Markers of dietary fat quality and fatty acid desaturation as predictors of total and cardiovascular mortality: a population-based prospective study

Dietary fatty acids and incident hip fractures in cohorts of women and men. A relative validation and follow-up study

OBJECTIVES

Hip fractures are associated with a high burden of morbidity and mortality. Diet is essential for preventing fragility fractures, but the role of dietary fatty acids on the risk of hip fracture is uncertain. The aim was to investigate how intake of different dietary fatty acids relates to the risk of hip fracture. A relative validation of the long-term intake of dietary fatty acids estimated from food frequency questionnaires (FFQs) was also performed.

DESIGN, SETTINGS AND PARTICIPANTS

We used data collected in two population-based cohorts, the Swedish Mammography Cohort and the Cohort of Swedish men (n = 83,603, 54% men, aged 45-82 years). Data from the repeated investigations in the cohorts and cross-sectional data from their clinical sub-cohorts were used.

MEASUREMENTS

Diet data was collected in FFQs. Incident hip fractures were gathered by individual linkage to national registers. We performed Cox regression analysis to investigate associations between dietary fatty acids and hip fracture. Follow-up time was between January 1st, 1998 and December 31st, 2020. The validation was performed using correlation analyses, comparing fatty acids measured in adipose tissue with estimated fatty acid intakes from FFQs.

RESULTS

During up to 23 years of follow-up (mean 18 years) and 1,538,627 person-years at risk, 7345 participants (2840 men) experienced a hip fracture. A low linoleic acid (LA) and high intakes of long-chain n-3 fatty acids were associated with higher hip fracture risk in a non-linear way. In quartile 4 compared to quartile 1 of LA, the multivariable-adjusted hazard ratio of hip fracture was 0.89 (95% Confidence Interval: 0.81, 0.97). The study confirmed the validity of FFQs to capture the intake of the specific dietary long-chain n-3 fatty acids. The estimated intake of LA, α-linolenic acid, and myristic acid were also adequately captured by the FFQs. Validity was confirmed in both women and men.

CONCLUSION

A low to moderate intake of linoleic acid and a higher intake of long-chain n-3 fatty acids were associated with a higher risk of hip fractures. The results indicate that attention should be paid to dietary fatty acid composition for the optimal prevention of fragility fractures.

Higher ratio of plasma omega-6/omega-3 fatty acids is associated with greater risk of all-cause, cancer, and cardiovascular mortality: A population-based cohort study in UK Biobank

Background

Circulating omega-3 and omega-6 polyunsaturated fatty acids (PUFAs) have been associated with various chronic diseases and mortality, but results are conflicting. Few studies examined the role of omega-6/omega-3 ratio in mortality.

Methods

We investigated plasma omega-3 and omega-6 PUFAs and their ratio in relation to all-cause and cause-specific mortality in a large prospective cohort, the UK Biobank. Of 85,425 participants who had complete information on circulating PUFAs, 6461 died during follow-up, including 2794 from cancer and 1668 from cardiovascular disease (CVD). Associations were estimated by multivariable Cox proportional hazards regression with adjustment for relevant risk factors.

Results

Risk for all three mortality outcomes increased as the ratio of omega-6/omega-3 PUFAs increased (all Ptrend <0.05). Comparing the highest to the lowest quintiles, individuals had 26% (95% CI, 15-38%) higher total mortality, 14% (95% CI, 0-31%) higher cancer mortality, and 31% (95% CI, 10-55%) higher CVD mortality. Moreover, omega-3 and omega-6 PUFAs in plasma were all inversely associated with all-cause, cancer, and CVD mortality, with omega-3 showing stronger effects.

Conclusions

Using a population-based cohort in UK Biobank, our study revealed a strong association between the ratio of circulating omega-6/omega-3 PUFAs and the risk of all-cause, cancer, and CVD mortality.

Funding

Research reported in this publication was supported by the National Institute of General Medical Sciences of the National Institute of Health under the award number R35GM143060 (KY). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Higher ratio of plasma omega-6/omega-3 fatty acids is associated with greater risk of all-cause, cancer, and cardiovascular mortality: a population-based cohort study in UK Biobank

Background

Circulating omega-3 and omega-6 polyunsaturated fatty acids (PUFAs) have been associated with various chronic diseases and mortality, but results are conflicting. Few studies examined the role of omega-6/omega-3 ratio in mortality.

Methods

We investigated plasma omega-3 and omega-6 PUFAs and their ratio in relation to all-cause and cause-specific mortality in a large prospective cohort, the UK Biobank. Of 85,425 participants who had complete information on circulating PUFAs, 6,461 died during follow-up, including 2,794 from cancer and 1,668 from cardiovascular disease (CVD). Associations were estimated by multivariable Cox proportional hazards regression with adjustment for relevant risk factors.

Results

Risk for all three mortality outcomes increased as the ratio of omega-6/omega-3 PUFAs increased (all Ptrend < 0.05). Comparing the highest to the lowest quintiles, individuals had 26% (95% CI, 15-38%) higher total mortality, 14% (95% CI, 0-31%) higher cancer mortality, and 31% (95% CI, 10-55%) higher CVD mortality. Moreover, omega-3 and omega-6 PUFAs in plasma were all inversely associated with all-cause, cancer, and CVD mortality, with omega-3 showing stronger effects.

Conclusions

Using a population-based cohort in UK Biobank, our study revealed a strong association between the ratio of circulating omega-6/omega-3 PUFAs and the risk of all-cause, cancer, and CVD mortality.

Effect of Primary Versus Revisional One Anastomosis Gastric Bypass (OAGB) on Fatty Acid Profile

INTRODUCTION

One anastomosis gastric bypass (OAGB) is one option of a revisional procedure for failed sleeve gastrectomy. Moreover, it can be used as a primary bariatric procedure, and is an effective surgery resulting in significant weight loss and the resolution or improvement of obesity-associated medical problems, accompanied by low perioperative complications. However, as with any therapy, OAGB has its limitations, including micronutrient deficiency or malnutrition. In our study, we compared the fatty acid (FA) profile in serum of patients after both primary OAGB (pOAGB) and revisional OAGB (rOAGB) to identify potential postsurgical FA alterations.

METHODS

This is a retrospective study on patients with obesity who underwent OAGB procedures (pOAGB n=68; rOAGB n=17), conducted from 2016 to 2018. In blood, we analyzed a series of biochemical parameters, and in the serum, the FA profile was determined using gas chromatography-mass spectrometry.

RESULTS

The percentage of excess BMI loss (% EBMIL) after pOAGB was 73.5 ± 2.47% in comparison to 45.9 ± 4.15% in the rOAGB group (p<0.001). In contrast to the lack of effect of rOAGB on most polyunsaturated FAs, in the pOAGB group, there was a decrease in eicosapentaenoic acid, and eicosatetraenoic and docosahexaenoic acid levels (p<0.001). We also found a decrease in very long-chain FAs (VLCFAs) and an increase in branched-chain FAs (BCFAs) after both types of OAGB procedure.

CONCLUSIONS

Both OAGB procedures improved the profile of most FAs, leading to a decrease in VLCFAs, which are considered harmful, and an improvement in BCFAs, which are considered to be beneficial. There is a need to further investigate the possibility of n-3 polyunsaturated FA supplementation after pOAGB, due to the large decrease in these FAs after pOAGB.

SCD1 is the critical signaling hub to mediate metabolic diseases: Mechanism and the development of its inhibitors

Metabolic diseases, featured with dysregulated energy homeostasis, have become major global health challenges. Patients with metabolic diseases have high probability to manifest multiple complications in lipid metabolism, e.g. obesity, insulin resistance and fatty liver. Therefore, targeting the hub genes in lipid metabolism may systemically ameliorate the metabolic diseases, along with the complications. Stearoyl-CoA desaturase 1(SCD1) is a key enzyme that desaturates the saturated fatty acids (SFAs) derived from de novo lipogenesis or diet to generate monounsaturated fatty acids (MUFAs). SCD1 maintains the metabolic and tissue homeostasis by responding to, and integrating the multiple layers of endogenous stimuli, which is mediated by the synthesized MUFAs. It critically regulates a myriad of physiological processes, including energy homeostasis, development, autophagy, tumorigenesis and inflammation. Aberrant transcriptional and epigenetic activation of SCD1 regulates AMPK/ACC, SIRT1/PGC1α, NcDase/Wnt, etc, and causes aberrant lipid accumulation, thereby promoting the progression of obesity, non-alcoholic fatty liver, diabetes and cancer. This review critically assesses the integrative mechanisms of the (patho)physiological functions of SCD1 in metabolic homeostasis, inflammation and autophagy. For translational perspective, potent SCD1 inhibitors have been developed to treat various types of cancer. We thus discuss the multidisciplinary advances that greatly accelerate the development of SCD1 new inhibitors. In conclusion, besides cancer treatment, SCD1 may serve as the promising target to combat multiple metabolic complications simultaneously.

Effects of Nutrition Education Program for the Japan Diet on Serum Phospholipid Fatty Acid Compositions in Patients with Dyslipidemia: Re-analysis of Data from a Previous Randomized Controlled Trial

AIM

We investigated changes in serum phospholipid fatty acid compositions with intake of the Japan Diet (JD) (higher consumption of fish, soybeans, vegetables, seaweed/mushrooms/konjak, and unrefined cereals with reduced consumption of animal fat, meat and poultry with fat, sweets and alcoholic drinks) recommended by the Japan Atherosclerosis Society.

METHODS

A randomized parallel controlled clinical trial on JD intake was conducted on Japanese patients with dyslipidemia. Nutrition education, based on the JD or partial JD (PJD) at baseline and at 3 months, was provided and the participants were followed up for 6 months. Fatty acids comprising serum phospholipids were measured in the JD (n=44) and PJD (n=44) groups.

RESULTS

Fatty acid intakes of C20:4, C20:5 and C22:6 increased in the JD group as compared with the PJD group. The percentages of serum phospholipid, C22:1 and C20:5 increased, while those of C18:1, C20:3(n-6) and C20:4(n-6) decreased in the JD as compared with the PJD group at 3 months. Changes in the phospholipid concentrations of C20:5, C22:5 and C22:6 reflected those intake volumes. Serum phospholipid C20:5 and C22:6 showed inverse correlations with C18:1, C18:2, and C20:3(n-6) at baseline and the changes at 3 and 6 months. In contrast, no correlation was observed between C20:4(n-6) and those n-3 fatty acids. The ratios of fatty acid concentrations, C16:1/C16:0 and C18:1/C18:0, decreased, but the ratio of C20:4(n-6)/C20:3(n-6) increased in the JD group.

CONCLUSION

Nutrition education on the JD changed serum phospholipid fatty acid profiles in favor to prevent against cardiovascular risk factors in patients with dyslipidemia.

Stearic Acid, but not Palmitic Acid, is Associated with Inflammatory and Endothelial Dysfunction Biomarkers in Individuals at Cardiovascular Risk

BACKGROUND

Several studies have associated dietary saturated fatty acids (SFAs) with cardiovascular risk but there are still many controversies. Most of these studies have focused on the effects of palmitic acid on circulating lipids. Stearic acid usually shows a neutral effect on blood lipids, however, there is a lack of clinical studies assessing the link with inflammatory and endothelial dysfunction markers.

OBJECTIVE

To evaluate the association of red blood cell (RBC) SFA (palmitic and stearic acids) with circulating inflammatory and endothelial dysfunction biomarkers.

METHODS

Cross-sectional study of 79 adults of both sexes with at least one cardiovascular risk factor but without previous events (acute myocardial infarction or stroke). Plasma biomarkers - lipids, glucometabolic markers, high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), interleukin-10 (IL-10), monocyte chemoattractant protein-1 (MCP-1), and tumor necrosis factor-α (TNF-α) - and RBC palmitic and stearic fatty acids were analyzed. The associations were assessed by correlation and multiple linear regression analyses, with statistical significance set at p < 0.05.

RESULTS

Palmitic acid showed no significant associations with traditional cardiovascular risk factors or inflammatory markers. Stearic acid, on the other hand, was inversely correlated with blood cholesterol and triglycerides, but independently associated with hs-CRP, IL-6, and TNF-α.

CONCLUSION

Stearic acid is associated with inflammatory and endothelial dysfunction biomarkers in individuals with at least one cardiovascular risk factor.

Dietary intake, biomarkers and supplementation of fatty acids and risk of coronary events: a systematic review and dose-response meta-analysis of randomized controlled trials and prospective observational studies

We aimed to review the association of dietary fats and risk of coronary events in adults. We searched PubMed, Embase, CENTRAL, Scopus, and Web of Sciences to April 2022 for prospective cohorts and randomized trials investigating the association of dietary intake and biomarkers of fats and fatty acid interventions and the risk of coronary events. We performed random-effects meta-analyses to estimate relative risk (RR) for the top versus bottom tertiles of exposures. One-hundered sixty-five prospective cohorts and randomized trials were included. Dietary intake and biomarkers of total fat and saturated, monounsaturated, and polyunsaturated fatty acids were not associated with the risk of coronary events. Dietary intake of trans fatty acids, palmitic acid, stearic acid, and saturated fatty acids from meat and unprocessed meat was modestly associated with a higher risk and, in contrast, intake of alpha-linolenic acid, long-chain omega-3 fatty acids, and linoleic acid was modestly associated with a lower risk. Supplementation with long-chain omega-3 fatty acids and increasing the consumption of alpha-linolenic and linoleic acids in place of saturated fats reduced the risk of coronary events. Existing evidence, in its totality, provides a modest support in favor of current recommendations suggesting replacement of saturated fats with polyunsaturated fats.

Role of Stearoyl-CoA Desaturase 1 in Cardiovascular Physiology

Stearoyl-CoA desaturase is a rate-limiting enzyme in the synthesis of monounsaturated fatty acids. Monounsaturated fatty acids limit the toxicity of exogenous saturated fats. Studies have shown that stearoyl-CoA desaturase 1 is involved in the remodeling of cardiac metabolism. The loss of stearoyl-CoA desaturase 1 reduces fatty acid oxidation and increases glucose oxidation in the heart. Such a change is protective under conditions of a high-fat diet, which reduces reactive oxygen species-generating β-oxidation. In contrast, stearoyl-CoA desaturase 1 deficiency predisposes individuals to atherosclerosis under conditions of hyperlipidemia but protects against apnea-induced atherosclerosis. Stearoyl-CoA desaturase 1 deficiency also impairs angiogenesis after myocardial infarction. Clinical data show a positive correlation between blood stearoyl-CoA Δ-9 desaturation rates and cardiovascular disease and mortality. Moreover, stearoyl-CoA desaturase inhibition is considered an attractive intervention in some obesity-associated pathologies, and the importance of stearoyl-CoA desaturase in the cardiovascular system might be a limitation for developing such therapy. This review discusses the role of stearoyl-CoA desaturase 1 in the regulation of cardiovascular homeostasis and the development of heart disease and presents markers of systemic stearoyl-CoA desaturase activity and their predictive potential in the diagnosis of cardiovascular disorders.

Characterization of serum polyunsaturated fatty acid profile in patients with inflammatory bowel disease

Background:

Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the digestive tract. The aetiology and pathogenesis of IBD are complex, which may lead to metabolic disorders. As a kind of metabolite, polyunsaturated fatty acid (PUFA) is closely related to IBD.

Objectives:

The aim of this study was to explore the correlation between the serum PUFAs and the pathogenesis of IBD.

Design:

The study is a hospital-based case-control study.

Methods:

The serum free PUFAs of all participants, including 104 patients with IBD and 101 normal controls, were detected by liquid chromatography–mass spectrometry (LC-MS).

Results:

Compared with the normal control, the levels of C18:2, α-C18:3 (ALA), ɤ-C18:3, C20:4 (AA), C20:5 (EPA), ω-3 C22:5, ω-6 C22:5 and C22:6 (DHA) PUFAs in patients with Crohn’s disease (CD) were obviously decreased. However, in patients with ulcerative colitis (UC), the levels of AA, EPA, ω-3 C22:5, ω-6 C22:5 and DHA were downregulated. The concentrations of seven PUFAs were significantly downregulated in the active CD group. In addition, four PUFAs had comparatively higher levels in the remission UC group.

Conclusion:

The present study revealed substantial differences in the levels of serum fatty acids between normal controls and patients with IBD. In detail, patients with CD were deficient in PUFAs, including the essential fatty acids. Moreover, as the disease activity aggravated, some PUFAs decreased dramatically.

Saturated fatty acid biomarkers and risk of cardiometabolic diseases: A meta-analysis of prospective studies

Background and aims

Evidence regarding associations of circulating saturated fatty acids (SFAs) with chronic diseases is mixed. The objective of this study was to determine the associations between total or individual SFA biomarkers and the risk of cardiometabolic diseases.

Methods

Four electronic databases were searched from inception to March 2022. Three investigators independently assessed for inclusion and extracted data. Random-effects or fixed-effects models was used to estimate the pooled relative risks (RRs) and corresponding 95% confidence intervals (CIs) for the association of total or individual SFA biomarkers, including even-chain SFAs (e.g., 14:0, myristic acid; 16:0, palmitic acid; 18:0, stearic acid), odd-chain SFAs (e.g., 15:0, pentadecanoic acid; 17:0, margaric acid) and very-long-chain SFAs (VLCSFAs; e.g., 20:0, arachidic acid; 22:0, behenic acid; 24:0, lignoceric acid), with risk of incident type 2 diabetes (T2D), cardiovascular disease [CVD; coronary heart disease (CHD) inclusive of stroke], CHD and stroke.

Results

A total of 49 prospective studies reported in 45 articles were included. Higher concentration of circulating total SFAs was associated with an increasing risk of cardiometabolic diseases, the risk increased significantly by 50% for CVD (95%CI:1.31–1.71), 63% for CHD (95%CI:1.38–1.94), 38% for stroke (95%CI:1.05–1.82), respectively. Similarly, levels of even-chain SFAs were positively associated with higher risk of chronic diseases, with RRs ranging from 1.15 to 1.43. In contrast, the risk of cardiometabolic diseases was reduced with increasing odd-chain SFA levels, with RRs ranging from 0.62 to 0.91. A higher level of VLCSFAs corresponded to 19% reduction in CVD. Further dose-response analysis indicated that each 50% increment in percentage of total SFAs in circulating was associated with an 8% higher risk of T2D (RR: 1.08, 95%CI: 1.02–1.14) and trends toward higher risk of CVD (RR: 1.15, 95%CI: 0.98–1.34). Inverse linear relationships were observed between 17:0 biomarker and T2D or CVD risk.

Conclusion

Our findings support the current recommendations of reducing intake of saturated fat as part of healthy dietary patterns. Further studies are needed to confirm our findings on these SFAs in relation to cardiometabolic outcomes and to elucidate underlying mechanisms.

Systematic review registration

[https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022329182], identifier [CRD42022329182].

Effects of sugar-sweetened soda on plasma saturated and monounsaturated fatty acids in individuals with obesity: A randomized study

Background

High carbohydrate, i.e., sugars, intake potentially drives the liver into a lipogenic state leading to elevated plasma fatty acids. Excessive intake of saturated fat and sugar-sweetened soda induces liver fat accumulation, but studying the effect of high intake from sugar-sweetened soda on the de novo lipogenesis (DNL) fatty acids in long-term randomized trials is lacking.

Objective

To study the effect of consuming 1 L/day of sugar-sweetened soda, semi-skimmed milk (milk), aspartame-sweetened soda or water over 24 weeks on DNL-derived fatty acids (i.e., palmitate (primary outcome) and other saturated and monounsaturated fatty acids), and markers of stearoyl-CoA desaturase activity (SCD1) in plasma phospholipids (PL), cholesteryl esters (CE), and triglycerides (TG).

Design and methods

A randomized parallel study was conducted simultaneously at Aarhus University Hospital and Copenhagen University, Denmark, including (n = 41) individuals aged 20–50 years, with BMI of 26–40 kg/m², and without diabetes. The groups consisted of 9 individuals in the sugar-sweetened soda, 10 in the milk, 11 in the aspartame-sweetened soda, and 11 in the water. The change at 24 weeks was assessed and compared across the groups using ANCOVA and mixed-effects models. Correlations of fatty acid changes with liver fat accumulation (magnetic resonance imaging) were explored.

Results

After 24 weeks, the groups differed in palmitate proportions in PL, oleate in CE and PL, and palmitoleate and SCD1 in all fractions (p < 0.05). Compared with water, the relative proportion of palmitate in PL increased by approximately 1% during both sugar-sweetened soda (p = 0.011) and milk (p = 0.006), whereas oleate and palmitoleate increased only during sugar-sweetened soda (CE 2.77%, p < 0.001; PL 1.51%, p = 0.002 and CE 1.46%, PL 0.24%, TG 1.31%, all p < 0.001, respectively). Liver fat accumulation correlated consistently with changes in palmitoleate, whereas correlations with palmitate and oleate were inconsistent across lipid fractions.

Conclusions

Although both sugar-sweetened soda and milk increased palmitate in PL, only excess intake of sugar-sweetened soda increased palmitoleate in all lipid fractions and correlated with liver fat. In contrast, isocaloric milk intake did not increase plasma monounsaturated fatty acids.

Clinical trial registration

[https://clinicaltrials.gov/ct2/show/NCT00777647], identifier [NCT00777647].

Plasma FA composition in familial LCAT deficiency indicates SOAT2-derived cholesteryl ester formation in humans

Mutations in the LCAT gene cause familial LCAT deficiency (Online Mendelian Inheritance in Man ID: #245900), a very rare metabolic disorder. LCAT is the only enzyme able to esterify cholesterol in plasma, whereas sterol O-acyltransferases 1 and 2 are the enzymes esterifying cellular cholesterol in cells. Despite the complete lack of LCAT activity, patients with familial LCAT deficiency exhibit circulating cholesteryl esters (CEs) in apoB-containing lipoproteins. To analyze the origin of these CEs, we investigated 24 carriers of LCAT deficiency in this observational study. We found that CE plasma levels were significantly reduced and highly variable among carriers of two mutant LCAT alleles (22.5 [4.0-37.8] mg/dl) and slightly reduced in heterozygotes (218 [153-234] mg/dl). FA distribution in CE (CEFA) was evaluated in whole plasma and VLDL in a subgroup of the enrolled subjects. We found enrichment of C16:0, C18:0, and C18:1 species and a depletion in C18:2 and C20:4 species in the plasma of carriers of two mutant LCAT alleles. No changes were observed in heterozygotes. Furthermore, plasma triglyceride-FA distribution was remarkably similar between carriers of LCAT deficiency and controls. CEFA distribution in VLDL essentially recapitulated that of plasma, being mainly enriched in C16:0 and C18:1, while depleted in C18:2 and C20:4. Finally, after fat loading, chylomicrons of carriers of two mutant LCAT alleles showed CEs containing mainly saturated FAs. This study of CEFA composition in a large cohort of carriers of LCAT deficiency shows that in the absence of LCAT-derived CEs, CEs present in apoB-containing lipoproteins are derived from hepatic and intestinal sterol O-acyltransferase 2.

Omega-3 polyunsaturated fatty acid biomarkers and risk of type 2 diabetes, cardiovascular disease, cancer, and mortality

BACKGROUND & AIMS

Considerable attention has focused on the role of omega-3 polyunsaturated fatty acids (PUFA) in the prevention of cardiometabolic diseases, which has led to dietary recommendations to increase omega-3 fatty acid intake. A meta-analysis was conducted to summarize evidence from prospective studies regarding associations between omega-3 PUFA biomarkers and risk of developing major chronic diseases.

METHODS

Four electronic databases were searched for articles from inception to March 1, 2022. Random-effects model was used to estimate the pooled relative risk (RR) and 95% confidence intervals (CIs) for the association of omega-3 PUFAs, including α-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA), with risk of developing type 2 diabetes (T2D), cardiovascular disease (CVD), including coronary heart disease (CHD) and stroke, cancer, and mortality. The Grades of Recommendation, Assessment, Development and Evaluation assessment tool was used to rates the confidence in estimates.

RESULTS

A total of 67 prospective studies comprised of 310,955 participants were identified. Individual omega-3 PUFAs showed divergent associations with the study outcomes of interest. A significant inverse association with T2D risk was observed across categories of ALA (relative risk [RR]: 0.89, 95% confidence interval [CI]: 0.82-0.96), EPA (RR: 0.85, 95% CI: 0.72-0.99) and DPA (RR: 0.84, 95% CI: 0.73-0.96) biomarkers. The marine-origin omega-3 fatty acids biomarkers but not ALA was significantly associated with lower risks of total CVD, CHD, and overall mortality, with RRs ranging from 0.70 for DHA-CHD association to 0.85 for EPA-CHD association. A lower risk of colorectal cancer was observed at higher levels of DPA (RR: 0.76, 95% CI: 0.59-0.98) and DHA (RR: 0.80; 95% CI: 0.65-0.99), whereas no association was noted for other outcomes. In addition, a dose-response relationship was observed between an increasing level of EPA, DPA, or DHA biomarker and lower risk of CVD.

CONCLUSIONS

Higher concentrations of marine-derived omega-3 PUFA biomarkers were associated with a significantly reduced risk of total CVD, CHD, and total mortality. Levels of ALA were inversely associated with a lower risk of T2D but not CVD-related outcomes. These data support the dietary recommendations advocating the role of omega-3 PUFAs in maintaining an overall lower risk of developing cardiovascular disease and premature deaths.

Macronutrient Proportions and Fat Type Impact Ketogenicity and Shape the Circulating Lipidome in Dogs

Many physiological processes including ketogenesis are similar in dogs and humans, but there is little information available on the effect of carbohydrate restriction in dogs. Here, the ketogenicity and serum metabolic profiles of dogs were assessed after they had consumed high carbohydrate (HiCHO); high protein, low carbohydrate (PROT_LoCHO); or high fat, low carbohydrate (FAT_LoCHO) foods. Thirty-six dogs were fed HiCHO for 4 weeks, then randomized to PROT_LoCHO or FAT_LoCHO for 5 weeks. Dogs then crossed over to the other food for an additional 5 weeks. Generally, reduction of dietary carbohydrate by replacement with either protein or fat increased the energy required to maintain body weight, and fat had a greater effect. Postabsorptive energy availability derived mainly from glucose and triglycerides with HiCHO, from gluconeogenic amino acids and fatty acids with PROT_LoCHO, and from fatty acids and β-hydroxybutyrate with FAT_LoCHO. This study demonstrated that the reduction of carbohydrate in canine foods is potentially beneficial to dogs based on improvements in metabolism and supports the use of low-carbohydrate foods as safe and effective for healthy adult dogs.

Blood levels of omega-6 fatty acids and coronary heart disease: a systematic review and metaanalysis of observational epidemiology

Individual omega-6 polyunsaturated fatty acids (PUFAs), principally linoleic acid (LA) and arachidonic acid (AA), may have differential impacts on cardiovascular risk. We aimed to summarize the up-to-date epidemiology evidence on the relationship between blood levels of omega-6 PUFAs and the risk of coronary heart disease (CHD). Population-based studies determining PUFA levels in blood were identified until May 2021 in PubMed, Embase, Web of Science, and Cochrane Library. Random-effects meta-analyses of cohorts comparing the highest versus lowest category were conducted to combine study-specific risk ratios (RRs) with 95% confidence intervals (CIs). Blood levels of omega-6 PUFAs were compared between the CHD case and non-case, presented as a weight mean difference (WMD). Twenty-one cohorts and eleven case-control studies were included. The WMD was -0.71 (95% CI: -1.20, -0.21) for LA and 0.08 (95% CI: -0.28, 0.43) for AA. LA levels were inversely associated with total CHD risk (RR: 0.85, 95% CI: 0.71, 1.00), but not AA. Each one-SD increase in LA levels resulted in 10% reductions in the risk of fatal CHD (RR: 0.90, 95% CI: 0.86, 0.95), but not in non-fatal CHD. Such findings highlight that the current recommendation for optimal intakes of omega-6 PUFAs (most LA) may offer a coronary benefit in primary prevention.Supplemental data for this article is available online at https://doi.org/10.1080/10408398.2022.2056867 .

Liraglutide Lowers Palmitoleate Levels in Type 2 Diabetes. A Post Hoc Analysis of the LIRAFLAME Randomized Placebo-Controlled Trial

Background

Liraglutide is a glucose-lowering medication used to treat type 2 diabetes and obesity. It is a GLP-1 receptor agonist with downstream metabolic changes beyond the incretin system, such as reducing the risk of cardiovascular complications. The understanding of these changes is critical for improving treatment outcomes. Herein, we present a post hoc experimental analysis using metabolomic phenotyping to discover molecular mecphanisms in response to liraglutide.

Method

Plasma samples were obtained from The LiraFlame Study (ClinicalTrials.gov identifier: NCT03449654), a randomized double-blinded placebo-controlled clinical trial, including 102 participants with type 2 diabetes randomized to either liraglutide or placebo treatment for 26 weeks. Mass spectrometry-based metabolomics analyses were carried out on samples from baseline and the end of the trial. Metabolites (n=114) were categorized into pathways and linear mixed models were constructed to evaluate the association between changes in metabolites and liraglutide treatment.

Results

We found the free fatty acid palmitoleate was significantly reduced in the liraglutide group compared to placebo (adjusted for multiple testing p-value = 0.04). The activity of stearoyl-CoA desaturase-1 (SCD1), the rate limiting enzyme for converting palmitate into palmitoleate, was found significantly downregulated by liraglutide treatment compared to placebo (p-value = 0.01). These metabolic changes have demonstrated to be linked to insulin sensitivity and cardiovascular health.

Essential Polyunsaturated Fatty Acids in Blood from Patients with and without Catheter-Proven Coronary Artery Disease

Coronary artery disease (CAD) is the leading cause of death worldwide. Statins reduce morbidity and mortality of CAD. Intake of n-3 polyunsaturated fatty acid (n-3 PUFAs), particularly eicosapentaenoic acid (EPA), is associated with reduced morbidity and mortality in patients with CAD. Previous data indicate that a higher conversion of precursor fatty acids (FAs) to arachidonic acid (AA) is associated with increased CAD prevalence. Our study explored the FA composition in blood to assess n-3 PUFA levels from patients with and without CAD. We analyzed blood samples from 273 patients undergoing cardiac catheterization. Patients were stratified according to clinically relevant CAD (n = 192) and those without (n = 81). FA analysis in full blood was performed by gas chromatography. Indicating increased formation of AA from precursors, the ratio of dihomo-gamma-linolenic acid (DGLA) to AA, the delta-5 desaturase index (D5D index) was higher in CAD patients. CAD patients had significantly lower levels of omega-6 polyunsaturated FAs (n-6 PUFA) and n-3 PUFA, particularly EPA, in the blood. Thus, our study supports a role of increased EPA levels for cardioprotection.

The associations of circulating common and uncommon polyunsaturated fatty acids and modification effects on dietary quality with all-cause and disease-specific mortality in NHANES 2003-2004 and 2011-2012

BACKGROUND

Associations of dietary or supplementary intake of several unsaturated fatty acids and mortality have been widely studied but the results were still hitherto inconsistent or limited. It is still need to explore the effects of these fatty acids by using the objective biomarkers.

OBJECTIVE

We aimed to investigate the relevancy of several serum n-3 and n-6 fatty acids with all-cause and disease-specific mortality to confirm their health effects and effects on the associations between dietary quality and all-cause mortality.

METHODS

A total of 4132 people from NHANES 2003-2004 and 2011-2012 and the mortality information was confirmed from the NDI. CPH models adjusted for known risk factors were conducted to explore the associations between circulating n-3 and n-6 fatty acids and all-cause or CVD or cancer mortality under complex sampling. We further evaluated their effects on association between dietary quality and all-cause mortality.

RESULTS

A total of 437 deaths occurred during the mean follow-up of 83.34 months, including 157 CVD death and 100 cancer death. Serum LA, ALA, EPA and DHA were associated with all-cause mortality (HR in quintile5: LA:0.584, 95%CI: 0.387-0.882, Ptrend = 0.011; ALA:0.626, 95%CI: 0.432-0.907, Ptrend = 0.008; EPA:0.535, 95%CI: 0.375-0.764, Ptrend = 0.001; DHA:0.669, 95%CI: 0.468-0.955, Ptrend = 0.031). Additionally, serum EPA and ALA were respectively related to CVD and cancer mortality (Q5 HR: EPA:0.450, 95%CI: 0.23-0.854, Ptrend = 0.009; ALA:0.387, 95%CI: 0.167-0.900, Ptrend = 0.022). Serum AA, GLA, DGLA and SDA were not associated with any risk of mortality. The effect on all-cause mortality of the lower AHEI scores can be improved by adherence to a higher serum LA, EPA and DHA (in the lowest AHEI strata, LA in tertile3 compared to tertile1 HR:0.596, 95%CI: 0.366-0.970; EPA:0.660, 95%CI: 0.454-0.959; DHA:0.666, 95%CI; 0.444-1.000).

CONCLUSIONS

Our results support the recent dietary recommendations to increase the intake of plant-derived and marine-derived n-6 and n-3 to improve the ability of primary and secondary prevention.

Dietary Intake and Biomarkers of α-Linolenic Acid and Mortality: A Meta-Analysis of Prospective Cohort Studies

Background: The association between α-linolenic acid (ALA) and mortality is inconsistent and has not been summarized systematically.

Objective: The purpose was to conduct a meta-analysis that synthesized the results of prospective cohort studies to investigate associations between ALA intake and mortality.

Methods: We conducted a comprehensive search on PubMed, Embase, and Web of Science databases on May 1, 2021, for relevant prospective cohort studies which reported associations of ALA (assessed by dietary surveys and/or ALA concentrations in body tissues) with mortality from all-cause, cardiovascular disease (CVD), and other diseases. Multivariable-adjusted relative risks (RRs) were pooled by a random or fixed-effects model.

Results: A total of 34 prospective cohort studies, of which 17 reported dietary ALA intake, 14 for ALA biomarkers, and the remaining 3 reported both of intake and biomarkers. The studies included 6,58,634 participants, and deaths were classified into all-cause mortality (56,898), CVD mortality (19,123), and other diseases mortality (19,061). Pooled RRs of ALA intake were 0.93 (95% CI: 0.86, 1.01, I² = 71.2%) for all-cause mortality, 0.90 (95% CI: 0.83, 0.98, I² = 22.1%) for CVD mortality, and 0.94 (95% CI: 0.83, 1.06, I² = 73.3%) for other diseases mortality. The two-stage random-effects dose-response analysis showed a linear relationship between dietary ALA intake and CVD-mortality and each 0.5% energy increment of ALA intake was associated with a 5% lower risk of CVD-mortality (RR: 0.95; 95% CI: 0.90, 1.00). Pooled RRs per SD increment of ALA biomarkers were 0.99 (95% CI: 0.96, 1.01, I² = 27%) for all-cause mortality, 1.00 (95% CI: 0.98, 1.03, I² = 0%) for CVD mortality and 0.98 (95% CI: 0.95, 1.01, I² = 0%) for other diseases mortality.

Conclusions: This meta-analysis summarizing the available prospective cohort studies indicated that ALA intake was associated with reduced risk of mortality, especially CVD mortality. Our findings suggest that ALA consumption may be beneficial for death prevention. Systematic Review Registration:https://www.crd.york.ac.uk/PROSPERO; identifier: CRD42021264532.

Dietary intake and biomarkers of alpha linolenic acid and risk of all cause, cardiovascular, and cancer mortality: systematic review and dose-response meta-analysis of cohort studies

OBJECTIVE

To examine the associations between dietary intake and tissue biomarkers of alpha linolenic acid (ALA) and risk of mortality from all causes, cardiovascular disease (CVD), and cancer.

DESIGN

Systematic review and meta-analysis of prospective cohort studies.

DATA SOURCES

PubMed, Scopus, ISI Web of Science, and Google Scholar to 30 April 2021.

STUDY SELECTION

Prospective cohort studies that reported the risk estimates for death from all causes, CVD, and cancer.

DATA SYNTHESIS

Summary relative risks and 95% confidence intervals were calculated for the highest versus lowest categories of ALA intake using random effects and fixed effects models. Linear and non-linear dose-response analyses were conducted to assess the dose-response associations between ALA intake and mortality.

RESULTS

41 articles from prospective cohort studies were included in this systematic review and meta-analysis, totalling 1 197 564 participants. During follow-up ranging from two to 32 years, 198 113 deaths from all causes, 62 773 from CVD, and 65 954 from cancer were recorded. High intake of ALA compared with low intake was significantly associated with a lower risk of deaths from all causes (pooled relative risk 0.90, 95% confidence interval 0.83 to 0.97, I2=77.8%, 15 studies), CVD (0.92, 0.86 to 0.99, I2=48.2%, n=16), and coronary heart disease (CHD) (0.89, 0.81 to 0.97, I2=5.6%, n=9), and a slightly higher risk of cancer mortality (1.06, 1.02 to 1.11, I2=3.8%, n=10). In the dose-response analysis, a 1 g/day increase in ALA intake (equivalent to one tablespoon of canola oil or 0.5 ounces of walnut) was associated with a 5% lower risk of all cause (0.95, 0.91 to 0.99, I2=76.2%, n=12) and CVD mortality (0.95, 0.91 to 0.98, I2=30.7%, n=14). The pooled relative risks for the highest compared with lowest tissue levels of ALA indicated a significant inverse association with all cause mortality (0.95, 0.90 to 0.99, I2=8.2%, n=26). Also, based on the dose-response analysis, each 1 standard deviation increment in blood concentrations of ALA was associated with a lower risk of CHD mortality (0.92, 0.86 to 0.98, I2=37.1%, n=14).

CONCLUSIONS

The findings show that dietary ALA intake is associated with a reduced risk of mortality from all causes, CVD, and CHD, and a slightly higher risk of cancer mortality, whereas higher blood levels of ALA are associated with a reduced risk of all cause and CHD mortality only.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42021229487.

Zinc Deficiency, Plasma Fatty Acid Profile and Desaturase Activities in Hemodialysis Patients: Is Supplementation Necessary?

Background: Desaturation and elongation are critical processes in endogenous metabolic fatty acid pathways. Zinc (Zn) is a cofactor for desaturases and elongases enzymes. There is limited evidence regarding the relationships between biomarkers of Zn status, nutritional intake, plasma phospholipid fatty acid profile and clinical outcomes among patients undergoing hemodialysis (HD). Objective: To examine the relationships between dietary and serum levels of Zn and Cu/Zn ratio and to explore associations of these micronutrients with PUFA profile and estimated desaturase and elongase enzyme activities in serum phospholipids among HD patients. Methods: This study included 40 adult patients undergoing hemodialysis treatment. Repeated 24-h recalls were applied for dietary intake assessment. Serum concentration of Zn and Cu were determined using inductively coupled plasma mass spectrometry and fatty acid composition by gas-liquid chromatography. Desaturase and elongase activities were calculated from product-precursor fatty acid ratios. Results: Inadequate dietary Zn intake was found in 55% of HD patients. They all had serum Zn concentration below the reference value of 60 μg/dL (mean 38.8 ± 7.72 μg/dL). Adequate zinc intake was accompanied with significantly higher intake of energy, total fats, SFA, MUFA and proteins. There was no correlation between Zn serum status and Zn intake estimates. Serum Cu/Zn ratio was high, (2.76 ± 0.68), directly and significantly associated with HD period, CRP, BMI, VFA, and inversely with Kt/V, albumin, iron, and iPTH. The n-6/n-3 ratio in plasma phospholipids was elevated (12.25 ± 3.45) and patients with inadequate Zn intake had lower n-3 PUFA intake and status compared to those with adequate intake. Serum Zn concentrations were inversely correlated with linoleic/dihomo-γ-linolenic acid ratio (LA/DGLA) (p = 0.037), related to D6-desaturase activity (p = 0.033) and directly with DGLA relative abundances (p = 0.024). Cu status was inversely associated with EPA level (p = 0.03) and estimates of elongase activity (p = 0.001). Furthermore, positive relationship was found between the Cu/Zn ratio and determined elongase value (p = 0.01). Conclusion: Findings of this study underpin the high prevalence of Zn deficiency and inadequate n-3 PUFA intake and status among subjects undergoing HD. The results obtained indicate that the assessment of Zn status should be a standard parameter of nutritional status screening in HD patients while emphasizing the importance of Cu/Zn determination. Although further research is warranted, Zn and-n-3 PUFA supplementation in HD patients might be beneficial for the prevention and attenuation of adverse health outcomes.

Serum Levels of Dihomo-Gamma (γ)-Linolenic Acid (DGLA) Are Inversely Associated with Linoleic Acid and Total Death in Elderly Patients with a Recent Myocardial Infarction

Dihomo-gamma-linolenic acid (DGLA) is an n-6 polyunsaturated fatty acid (PUFA) derived from linoleic acid (LA). The LA:DGLA ratio reflects conversion from LA to DGLA. Low levels of DGLA in serum have been related to poor outcome in myocardial infarction (MI) patients. Aims: To assess the association of DGLA and LA:DGLA with total death as a primary aim and incident cardiovascular events as a secondary objective. Methods: Baseline samples from 1002 patients, aged 70 to 82 years, included 2–8 weeks after an MI and followed for 2 years, were used. Major adverse clinical events (MACE) consisted of nonfatal MI, unscheduled coronary revascularization, stroke, hospitalization for heart failure or all-cause death. Cox regression analysis was used to relate serum n-6 PUFA phospholipid levels (%wt) to the risk of MACE, adjusting for the following: (1) age, sex and body mass index (BMI); (2) adding baseline cod liver oil supplementation; (3) adding prevalent hypertension, chronic kidney disease and diabetes mellitus. Results: Median DGLA level in serum phospholipids was 2.89 (Q1–Q3 2.43–3.38) %wt. DGLA was inversely related to LA and LA:DGLA ratio. There were 208 incident cases of MACE and 55 deaths. In the multivariable analysis, the hazard ratio (HR) for the total death in the three higher quartiles (Q2–4) of DGLA as compared to Q1 was 0.54 (0.31–0.95), with p = 0.03 (Model-1), 0.50 (0.28–0.91), with p = 0.02 (Model-2), and 0.47 (0.26–0.84), with p = 0.012 (Model-3), and non-significant for MACE. Risk of MACE (Model 3) approached borderline significance for LA:DGLA in Q2–4 vs. Q1 [HR 1.42 (1.00–2.04), p = 0.052]. Conclusions: Low levels of DGLA were related to a high LA:DGLA ratio and risk of total death in elderly patients with recent MI.

Alternative Dietary Patterns for Americans: Low-Carbohydrate Diets

The decades-long dietary experiment embodied in the Dietary Guidelines for Americans (DGA) focused on limiting fat, especially saturated fat, and higher carbohydrate intake has coincided with rapidly escalating epidemics of obesity and type 2 diabetes (T2D) that are contributing to the progression of cardiovascular disease (CVD) and other diet-related chronic diseases. Moreover, the lack of flexibility in the DGA as it pertains to low carbohydrate approaches does not align with the contemporary trend toward precision nutrition. We argue that personalizing the level of dietary carbohydrate should be a high priority based on evidence that Americans have a wide spectrum of metabolic variability in their tolerance to high carbohydrate loads. Obesity, metabolic syndrome, and T2D are conditions strongly associated with insulin resistance, a condition exacerbated by increased dietary carbohydrate and improved by restricting carbohydrate. Low-carbohydrate diets are grounded across the time-span of human evolution, have well-established biochemical principles, and are now supported by multiple clinical trials in humans that demonstrate consistent improvements in multiple established risk factors associated with insulin resistance and cardiovascular disease. The American Diabetes Association (ADA) recently recognized a low carbohydrate eating pattern as an effective approach for patients with diabetes. Despite this evidence base, low-carbohydrate diets are not reflected in the DGA. As the DGA Dietary Patterns have not been demonstrated to be universally effective in addressing the needs of many Americans and recognizing the lack of widely available treatments for obesity, metabolic syndrome, and T2D that are safe, effective, and sustainable, the argument for an alternative, low-carbohydrate Dietary Pattern is all the more compelling.

Metformin Affects Cardiac Arachidonic Acid Metabolism and Cardiac Lipid Metabolite Storage in a Prediabetic Rat Model

Metformin can reduce cardiovascular risk independent of glycemic control. The mechanisms behind its non-glycemic benefits, which include decreased energy intake, lower blood pressure and improved lipid and fatty acid metabolism, are not fully understood. In our study, metformin treatment reduced myocardial accumulation of neutral lipids—triglycerides, cholesteryl esters and the lipotoxic intermediates—diacylglycerols and lysophosphatidylcholines in a prediabetic rat model (p < 0.001). We observed an association between decreased gene expression and SCD-1 activity (p < 0.05). In addition, metformin markedly improved phospholipid fatty acid composition in the myocardium, represented by decreased SFA profiles and increased n3-PUFA profiles. Known for its cardioprotective and anti-inflammatory properties, metformin also had positive effects on arachidonic acid metabolism and CYP-derived arachidonic acid metabolites. We also found an association between increased gene expression of the cardiac isoform CYP2c with increased 14,15-EET (p < 0.05) and markedly reduced 20-HETE (p < 0.001) in the myocardium. Based on these results, we conclude that metformin treatment reduces the lipogenic enzyme SCD-1 and the accumulation of the lipotoxic intermediates diacylglycerols and lysophosphatidylcholine. Increased CYP2c gene expression and beneficial effects on CYP-derived arachidonic acid metabolites in the myocardium can also be involved in cardioprotective effect of metformin.

The Interaction Between Fatty Acid Desaturase-2 (FADS2) rs174583 Genetic Variant and Dietary Quality Indices (DASH and MDS) Constructs Different Metabolic Phenotypes Among Obese Individuals

Background and Aim: Genetic variation in fatty acid desaturases (FADS) has previously been linked to several diet-related diseases. We aimed to determine whether the FADS2 rs174583 variant interacts with the Dietary Approach to Stop Hypertension (DASH) score and Mediterranean dietary score (MDS) to influence cardio-metabolic risk factors among obese adults. Methods: This cross-sectional study was performed among 347 apparently healthy obese adults (aged 20-50 years). Dietary quality indicator scores (DASH and MDS) were generated using a validated 147-item Food Frequency Questionnaire (FFQ). The FADS2 rs174583 variant was genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The gene-diet interaction was analyzed by the ANCOVA multivariate interaction model. Results: A significant interaction was observed between rs174583 and adherence to the DASH score in relation to serum triglyceride (TG) concentration among the female group (P Interaction = 0.046); CT-genotype carriers who were assigned to the second tertile of DASH compared with those in the first tertile had a lower TG level (P < 0.05). Another significant interaction was revealed between adherence to MDS score and rs174583 polymorphism on serum glucose levels (P Interaction = 0.044); the lowest mean of glucose level was observed in homozygous minor subjects (TT) in the third tertile of MDS, in comparison with other tertiles of this dietary index (P < 0.05). There was a similar significant interaction between DASH and rs174583 in relation to diastolic blood pressure (P Interaction = 0.038) among the male group. Additionally, a significant positive association was found between TT genotype and odds of having high TG both in the crude (OR, 3.21; 95% CI, 1.02-10.14) and adjusted (OR, 3.58; 95% CI, 1.07-11.97) models, taking into account different confounders. Conclusion: Adherence to the dietary quality indicators (DASH and MDS) modified the relationship between FADS2 rs174583 polymorphism and cardio-metabolic risk factors in obese subjects. Prospective cohort studies are needed to confirm the results of our study.

Effects of Palm Stearin versus Butter in the Context of Low-Carbohydrate/High-Fat and High-Carbohydrate/Low-Fat Diets on Circulating Lipids in a Controlled Feeding Study in Healthy Humans

Background. Foods rich in saturated fatty acids (SFAs) have been discouraged by virtue of their cholesterol-raising potential, but this effect is modulated by the food source and background level of carbohydrate. Objective. We aimed to compare the consumption of palm stearin (PS) versus butter on circulating cholesterol responses in the setting of both a low-carbohydrate/high-fat (LC/HF) and high-carbohydrate/low-fat (HC/LF) diet in healthy subjects. We also explored effects on plasma lipoprotein particle distribution and fatty acid composition. Methods. We performed a randomized, controlled-feeding, cross-over study that compared a PS- versus a Butter-based diet in a group of normocholesterolemic, non-obese adults. A controlled canola oil-based ‘Run-In’ diet preceded the experimental PS and Butter diets. All diets were eucaloric, provided for 3-weeks, and had the same macronutrient distribution but varied in primary fat source (40% of the total fat). The same Run-In and cross-over experiments were done in two separate groups who self-selected to either a LC/HF (n = 12) or a HC/LF (n = 12) diet track. The primary outcomes were low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein (HDL)-C, triglycerides, and LDL particle distribution. Results. Compared to PS, Butter resulted in higher LDL-C in both the LC/HF (13.4%, p = 0.003) and HC/LF (10.8%, p = 0.002) groups, which was primarily attributed to large LDL I and LDL IIa particles. There were no differences between PS and Butter in HDL-C, triglycerides, or small LDL particles. Oxidized LDL was lower after PS than Butter in LC/HF (p = 0.011), but not the HC/LF group. Conclusions. These results demonstrate that Butter raises LDL-C relative to PS in healthy normocholesterolemic adults regardless of background variations in carbohydrate and fat, an effect primarily attributed to larger cholesterol-rich LDL particles.

Altered Indices of Fatty Acid Elongases ELOVL6, ELOVL5, and ELOVL2 Activities in Patients with Impaired Fasting Glycemia

Background: Dysregulation of fatty acids (FA) seems to participate in the pathogenesis of disorders such as metabolic syndrome (MetS), cardiovascular diseases, or some cancers. Activities of enzymes FA desaturases and elongases [elongation of very long-chain fatty acid (ELOVL)] significantly influence FA profile in different body compartments. Although the impact of activities of desaturases on cardiometabolic diseases was broadly studied, relatively little attention was devoted to the role of elongases. Methods: Case-control study was carried out in 36 patients (18 men/18 women) with impaired fasting glycemia (IFG) without MetS and 36 age and gender-matched healthy controls. FA profiles in plasma phospholipids (PL) were assessed using gas chromatograph-flame ionization detector and indices of desaturase and elongase activities were calculated. Results: In the IFG group, we observed decreased estimated activities of ELOVL2 and ELOVL5, whereas higher estimated activities of elongase ELOVL6 were noted. IFG group was also characterized by altered composition of plasma PL FA, above all by lower percentage of cis-vaccenic acid (cVA; 18:1n-7) and of total polyunsaturated FA n-6, especially linoleic acid, and by higher proportion of stearic acid and gamma-linolenic acid. Concurrently, elevated estimated activities of desaturases delta-9-desaturase (D9D), D6D were found. Conclusions: Lower estimated activities of ELOVL2 and ELOVL5 with lowered proportion of PL cVA could be associated with disturbances of glucose homeostasis development and their corresponding indices could serve as biomarkers of such risk.

Impact of curcumin on fatty acid metabolism

Free fatty acids (FFAs) and fatty acid synthesis (FAS) activity have significantly contributed to disease states such as insulin resistance, obesity, type 2 diabetes, myocardial infarction, blood pressure, and several types of cancer. Currently, several treatment options are available for patients with these conditions. Due to safety concerns, adverse effects, limited efficacy, and low tolerability associated with many medications, the identification of novel agents with less toxicity and a more favorable outcome is warranted. Curcumin is a phenolic compound derived from the turmeric plant with various biological activities, including anticarcinogenic, antioxidant, antiinflammatory, and hypolipidemic properties. PubMed, Scopus, and Web of Science were searched up to February 2020 for studies that demonstrated the efficacy and mechanisms of curcumin action on FFAs, FAS, and β-oxidation activity, as well as the desaturation system. Most of the evidence is in-vivo and in-vitro studies that demonstrate that curcumin possesses regulatory properties on FFAs levels through its effects on FAS and β-oxidation activity as well as desaturation system, which could improve insulin resistance, obesity, and other FFAs-related disorders. The present study provides a review of the existing in-vitro, in-vivo, and clinical evidence on the effect of curcumin on FFAs and FAS activity, β-oxidation, and desaturation system.

Technofunctional quality assessment of soymilk fermented with Lactobacillus acidophilus and Lactobacillus casei

The current research work was carried out to evaluate the effect of three different varieties (NARC-II, Williams 82, Ajmeri) of soybean along with single and coculture impact of Lactobacillus acidophilus and Lactobacillus casei on fermented soymilk. The periodically microbial and antioxidative activities of fermented soymilk were analyzed during the storage of 24 days. Moreover, the effect of fermentation on rheological and structural changes was examined along with isoflavone contents in fermented soymilk. Viability of cells and antioxidative activities were found to be significantly (P < 0.05) higher in fermented soymilk using mixed cultures. The rheological attributes demonstrated higher viscosity in coculture fermented soymilk. Scanning electron microscopic examination indicated that the growth characteristic of L. casei has a relatively more uniform texture and smaller pore size in comparison to L. acidophilus. Nevertheless, the combination of cultures exhibited precise pore formation with stronger cross-links of soybean protein throughout the structure. Assessment of isoflavones exhibited higher values, for daidzein (20.87 ppm) in comparison to genistein (6.57 ppm), in Ajmeri-based coculture soymilk. Conclusively, L. casei and L. acidophilous exhibited considerable antioxidant potential in the development of viscous, less porous, and rich in bioactive metabolites fermented soymilk, when used in combination and among varieties Ajmeri results it was the top of all. This suggests that the process evidence in this study could be recommended for high-quality soymilk production.

Dietary fat and alcohol in the prediction of indices of vascular health among young adults

OBJECTIVES

Arterial stiffness, particularly of the aorta, is an independent predictor of future cardiovascular disease, all-cause mortality, and hypertension. Arterial stiffening may be caused or exacerbated by the composition of the diet. Current research has indicated that habitual dietary patterns may influence arteriosclerosis, or the thickening and hardening of the artery walls, but has yet to identify a specific food group as the culprit. In young, college-aged adults, dietary fat intake and alcohol consumption tend to be higher compared to other periods throughout the life cycle. Therefore, the purpose of this study was to determine the influence of dietary fat and alcohol consumption on the vascular health of apparently healthy young adults.

METHODS

The data collected were assessed to determine if dietary fat and alcohol in young (18-30 y), college-aged adults (n = 50) were independent predictors of an increase in arterial stiffening. Vascular health was determined by the carotid-femoral pulse-wave velocity and the augmentation index corrected for a heart rate of 75 beats/min; dietary patterns were assessed using the Dietary Health Questionnaire II.

RESULTS

The gold standard marker of aortic stiffness, carotid femoral pulse-wave velocity, was positively correlated with cheese consumption (R² = 0.092, P = 0.033), alcohol consumption (R² = 0.102, P = 0.024), and total energy/calories (%) from alcohol (R² = 0.118, P = 0.015) in univariate analysis. In forward-selection multiple regression analysis, energy from alcohol and cheese consumption accounted for 23.7% of the variance in carotid-femoral pulse-wave velocity (P = 0.009). The augmentation index wave reflection marker was positively correlated with total dietary fat (R² = 0.110, P = 0.019), trans fatty acids (R² = 0.092, P = 0.032), saturated fatty acids (R² = 0.124, P = 0.012), monounsaturated fatty acids (R² = 0.012, P = 0.015), red-meat consumption (R² = 0.094, P = 0.030), and discretionary fat from solids in univariate analysis (R² = 0.137, P = 0.008). Discretionary fat from solids accounted for 13.7% of the variation in augmentation index in forward-selection multiple regression analysis (P = 0.008).

CONCLUSIONS

These results indicate the potential roles of dietary fat and alcohol consumption in early vascular aging by stiffening the arteries of young, college-aged adults, which may in turn contribute to future adverse cardiovascular disease outcomes.

Genetic variants for personalised management of very low carbohydrate ketogenic diets

The ketogenic diet (KD) is a low-carbohydrate, high-fat, adequate-protein diet proven to be effective for the reversal of obesity, metabolic syndrome and type 2 diabetes, and holding therapeutic potential for the prevention and treatment of other chronic diseases. Genetic and dynamic markers of KD response may help to identify individuals most likely to benefit from KD and point to individuals at higher risk for adverse health outcomes. Here, we provide a clinician-friendly review of state-of-the-art research on biomarkers of KD response for a variety of outcomes including weight loss, body composition and cognitive performance drawing data from both intervention trials and case reports of rare inborn errors of metabolism. We also present a selection of the most promising candidate genes to evaluate in future studies and discuss key aspects of study design and variant interpretation that may help accelerate the implementation of these biomarkers in clinical practice.

Plasma metabolomics are associated with metabolic syndrome: A targeted approach

OBJECTIVES

Advances in metabolomic tools have allowed us to gain a more comprehensive understanding of metabolic syndrome (MetS). The aim of this study was to evaluate the association between plasma metabolomic profiles and MetS.

METHODS

For this study, adults without diabetes, chronic kidney disease, stroke, heart disease, or cancer and with full metabolomics, biochemical, and dietetic data available, representing a subsample of the Health Survey of Sao Paulo study (ISA-Capital; N = 130), were included. The joint interim statement consensus criteria were used for diagnosing MetS. Absolute quantification (µmol/L) of blood metabolites was achieved by targeted quantitative profiling of annotated metabolites by electrospray ionization tandem mass spectrometry in plasma samples. Mean differences in the compounds for MetS were evaluated by linear regression adjusted for confounding factors.

RESULTS

Serine was inversely associated with MetS (β = -15.04; P = 0.014). In glycerophospholipids with acyl-alkyl bonds, there was an inverse association with MetS, including phosphatidylcholine (PC) ae C42:5 (β = -0.15; P = 0.040), PC ae C44:5 (β = -0.15; P = 0.046), PC ae C40:4 (β = -0.21; P = 0.014) and PC ae C44:4 (β = -0.04; P = 0.032).

CONCLUSION

Plasma metabolomic profiles were associated with MetS, especially the amino acid serine and some acyl-alkyl PCs.

Relationships of Fatty Acids, Delta-5 Desaturase Activity, and Lipid Profiles in Men with Acute Coronary Syndrome

AIMS

We evaluated the relationship between the ratios of eicosapentaenoic acid and arachidonic acid (EPA/AA), docosahexaenoic acid (DHA)/AA, and delta-5 desaturase activity (D5D) and atherogenic lipid profiles (ALP) and coronary atherosclerosis.

METHODS

Polyunsaturated fatty acids (PUFA) and ALP were assessed in 436 men with the first episode of acute coronary syndrome (ACS) not take any lipid-lowering drugs. D5D was estimated as the ratio of AA to dihomogamma-linolenic acid (DGLA). These biomarkers were compared between the lower and higher levels of EPA/AA (0.41) or DHA/AA (0.93) according to the levels in Japanese general population. The thrombolysis in myocardial infarction flow (TIMI) grade of the culprit coronary artery was visually estimated during the initial angiography.

RESULTS

Approximately 70% of patients had low EPA/AA or DHA/AA. Serum levels of LDL-cholesterol, apolipoprotein B (apoB), and remnant lipoprotein cholesterol (RL-C) were significantly higher in the low EPA/AA or DHA/AA groups, while those of triglycerides and malondialdehyde-modified LDL (MDA-LDL) were significantly higher in the low EPA/AA group alone. The levels of EPA, EPA/AA, DHA/AA, and HbA1c increased and those of DGLA and apoA1 decreased with increasing number of stenotic vessels. Patients with three stenotic coronary vessels or TIMI grade ≥ 1 had significantly higher EPA levels compared with the others. The levels of LDL-cholesterol, non-HDL-cholesterol, triglycerides, small dense LDL-cholesterol, RL-C, MDA-LDL, apoB, and apoE decreased progressively and those of EPA, DHA, EPA/AA and HDL-cholesterol increased as D5D increased.

CONCLUSIONS

The EPA/AA is a superior risk marker than DHA/AA in term of correlation with ALP in ACS patients.

Integrative Analysis of Lipid Profiles in Plasma Allows Cardiometabolic Risk Factor Clustering in Children with Metabolically Unhealthy Obesity

Hypertension, central obesity, hyperglycemia, and dyslipidemia are key risk factors for cardiovascular disease. However, the specific factors contributing to the development of unfavorable cardiometabolic characteristics in children with obesity are unknown. In this study, we investigated the cross-sectional relationships between cytokines, irisin, and fatty acid (FA) composition in plasma in school-age children with metabolically healthy and unhealthy obesity (MHO and MUO, respectively) of the same age and body mass index and waist circumference percentiles. We compared the data with that of children with normal weight (NW). We found that inflammatory cytokines and low irisin plasma concentrations are associated with obesity but not with cardiometabolic risk (CMR). Lipid profiles showed that children with MUO have a distinctive FA profile compared with children with MHO and NW, whereas children with MHO shared 88% of the FA profile with the NW group. Among all FAs, concentration of myristic acid (14 : 0), arachidic acid (20 : 0), and n-3 polyunsaturated FAs (PUFAs) was higher in children with MHO, whereas n-6 PUFAs such as arachidonic acid (20 : 4n6) had a significant contribution in defining MUO. These data suggest that the plasma FA profile is not only a central link to obesity but also may act as an indicator of CMR presence.

Metabolic syndrome in postmenopausal women is associated with lower erythrocyte PUFA/MUFA and n-3/n-6 ratio: A case-control study

The aim of this study was to compare fatty acid (FA) intake and status in postmenopausal women with or without metabolic syndrome (MetS). 131 women were recruited to a case-control study in 2016-2018 in Poznań, Poland. Dietary intake, anthropometric and biochemical measurements, FA level in red blood cells (RBCs), and FADS1 (rs174546) and FADS2 (rs3834458) genotypes were determined. Compared to women without MetS, those with MetS had lower levels of EPA, n-3, EPA/α-linolenic acid (ALA), EPA/AA, DHA/AA, EPA+DHA/AA, PUFA/saturated FA, PUFA/monounsaturated FA, and n-3/n-6 ratios in RBCs. Participants with at least one minor allele of each polymorphism had lower levels of EPA, and EPA/AA, and a higher level of DHA/EPA in RBCs than did women with major alleles. MetS is associated with lower levels FAs that have a protective effect on cardiometabolic health. FADS1 and FADS2 polymorphisms are associated with unfavorable FA and status EPA/AA in RBC contributes to MetS.

Desaturase Activity and the Risk of Type 2 Diabetes and Coronary Artery Disease: A Mendelian Randomization Study

Estimated Δ5-desaturase (D5D) and Δ6-desaturase (D6D) are key enzymes in metabolism of polyunsaturated fatty acids (PUFA) and have been associated with cardiometabolic risk; however, causality needs to be clarified. We applied two-sample Mendelian randomization (MR) approach using a representative sub-cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam Study and public data from DIAbetes Genetics Replication And Meta-analysis (DIAGRAM) and Coronary ARtery DIsease Genome wide Replication and Meta-analysis (CARDIoGRAM) genome-wide association studies (GWAS). Furthermore, we addressed confounding by linkage disequilibrium (LD) as all instruments from FADS1 (encoding D5D) are in LD with FADS2 (encoding D6D) variants. Our univariable MRs revealed risk-increasing total effects of both, D6D and D5D on type 2 diabetes (T2DM) risk; and risk-increasing total effect of D6D on risk of coronary artery disease (CAD). The multivariable MR approach could not unambiguously allocate a direct causal effect to either of the individual desaturases. Our results suggest that D6D is causally linked to cardiometabolic risk, which is likely due to downstream production of fatty acids and products resulting from high D6D activity. For D5D, we found indication for causal effects on T2DM and CAD, which could, however, still be confounded by LD.

Dietary intake and biomarkers of linoleic acid and mortality: systematic review and meta-analysis of prospective cohort studies

BACKGROUND

Current evidence on associations between intakes of linoleic acid (LA), the predominant n-6 (ω-6) fatty acid, and mortality is inconsistent and has not been summarized by a systematic review and meta-analysis.

OBJECTIVE

The aim was to perform a systematic review and meta-analysis of prospective cohort studies to examine associations between LA intake and mortality.

METHODS

We conducted a comprehensive search of MEDLINE and EMBASE databases through 31 July 2019 for prospective cohort studies reporting associations of LA (assessed by dietary surveys and/or LA concentrations in adipose tissue or blood compartments) with mortality from all causes, cardiovascular disease (CVD), and cancer. Multivariable-adjusted RRs were pooled using random-effects meta-analysis.

RESULTS

Thirty-eight studies reporting 44 prospective cohorts were identified; these included 811,069 participants with dietary intake assessment (170,076 all-cause, 50,786 CVD, and 59,684 cancer deaths) and 65,411 participants with biomarker measurements (9758 all-cause, 6492 CVD, and 1719 cancer deaths). Pooled RRs comparing extreme categories of dietary LA intake (high vs low) were 0.87 (95% CI: 0.81, 0.94; I2 = 67.9%) for total mortality, 0.87 (95% CI: 0.82, 0.92; I2 = 3.7%) for CVD mortality, and 0.89 (95% CI: 0.85, 0.93; I2 = 0%) for cancer mortality. Pooled RRs for each SD increment in LA concentrations in adipose tissue/blood compartments were 0.91 (95% CI: 0.87, 0.95; I2 = 64.1%) for total mortality, 0.89 (95% CI: 0.85, 0.94; I2 = 28.9%) for CVD mortality, and 0.91 (95% CI: 0.84, 0.98; I2 = 26.3%) for cancer mortality. Meta-regressions suggested baseline age and dietary assessment methods as potential sources of heterogeneity for the association between LA and total mortality.

CONCLUSIONS

In prospective cohort studies, higher LA intake, assessed by dietary surveys or biomarkers, was associated with a modestly lower risk of mortality from all causes, CVD, and cancer. These data support the potential long-term benefits of PUFA intake in lowering the risk of CVD and premature death.

Saturated Fats and Health: A Reassessment and Proposal for Food-Based Recommendations: JACC State-of-the-Art Review

The recommendation to limit dietary saturated fatty acid (SFA) intake has persisted despite mounting evidence to the contrary. Most recent meta-analyses of randomized trials and observational studies found no beneficial effects of reducing SFA intake on cardiovascular disease (CVD) and total mortality, and instead found protective effects against stroke. Although SFAs increase low-density lipoprotein (LDL) cholesterol, in most individuals, this is not due to increasing levels of small, dense LDL particles, but rather larger LDL particles, which are much less strongly related to CVD risk. It is also apparent that the health effects of foods cannot be predicted by their content in any nutrient group without considering the overall macronutrient distribution. Whole-fat dairy, unprocessed meat, and dark chocolate are SFA-rich foods with a complex matrix that are not associated with increased risk of CVD. The totality of available evidence does not support further limiting the intake of such foods.

Fatty Acid Profile and Desaturase Activities in 7-10-Year-Old Children Attending Primary School in Verona South District: Association between Palmitoleic Acid, SCD-16, Indices of Adiposity, and Blood Pressure

In previous studies, dietary and circulating fatty acids (FA) and desaturases activity (delta-5 desaturase [D5D], delta-6 desaturase [D6D], and stearoyl-CoA desaturase [SCD-16]) involved in their metabolism were associated with metabolic and cardiovascular disorders. The aim of the study was to assess the association between different FAs and desaturases activity (estimated as product:precursor ratios) with individual cardiovascular risk factors (in particular, anthropometric measurements and blood pressure [BP]) in children. The FA profile was determined on a whole-blood drop in 243 children (age: 8.6 ± 0.72 years) participating in a school-based cross-sectional study. Docosahexaenoic acid (DHA) inversely correlated with indices of adiposity, glucose, and triglycerides. Palmitoleic acid and SCD-16 were directly associated with markers of adiposity and BP, even after adjustment for main confounders. D6D correlated directly with the waist/height ratio. Children with excess weight (>85th percentile; that is overweight plus obese ones) showed higher palmitic acid, palmitoleic acid, and higher SCD-16 activity as compared to normal-weight children. Most of the associations were confirmed in the excess-weight group. Omega-3 FAs, particularly DHA, but not omega-6 FA, showed a potentially beneficial association with metabolic parameters, whereas palmitoleic acid and SCD-16 showed a potentially harmful association with indices of adiposity and BP, especially in obese children.

Association between Plasma N-6 Polyunsaturated Fatty Acids Levels and the Risk of Cardiovascular Disease in a Community-based Cohort Study

Most studies support that saturated fatty acid replacement with polyunsaturated fatty acids (PUFAs) may reduce the risk of cardiovascular diseases (CVDs) and put emphasis on the effects of N-3 PUFAs. The reported relationships between N-6 PUFAs and CVD risks vary. We aimed to examine the associations between N-6 PUFA concentrations and CVD risks. In this community-based prospective cohort study on CVD-free patients at baseline (N = 1835, age: 60.6 ± 10.5 years, women: 44.5%), we measured the fatty acid concentrations in the blood using gas chromatography. Four hundred twenty-four participants developed CVDs during follow up. The total N-6 PUFA concentration was inversely associated with the CVD risk, with a 48% lower risk in the highest N-6 PUFA concentration quartile (hazard ratio = 0.52; P for trend <0.001). The estimated population attributable risk of N-6 PUFAs indicated that approximately 20.7% of CVD events would have been prevented if the plasma N-6 PUFA concentration had been higher than the median value. The total N-6 PUFA concentration presented the highest net reclassification improvement (NRI = 7.2%, P = 0.03) for predicting incident CVD. Further studies on N-6 PUFAs, diet habits, and their relationships with healthcare are warranted.

Plasma Phospholipid Fatty Acids, FADS1 and Risk of 15 Cardiovascular Diseases: A Mendelian Randomisation Study

Whether circulating fatty acids (FAs) play a causal role in the development of cardiovascular disease (CVD) remains unclear. We conducted a Mendelian randomisation study to explore the associations between plasma phospholipid FA levels and 15 CVDs. Summary-level data from the CARDIoGRAMplusC4D, MEGASTROKE, and Atrial Fibrillation consortia and UK Biobank were used. Sixteen single-nucleotide polymorphisms (SNPs) associated with ten plasma FAs were used as instrumental variables. SNPs in or close to the FADS1 gene were associated with most FAs. We performed a secondary analysis of the association between a functional variant (rs174547) in FADS1, which encodes ?5-desaturase (a key enzyme in the endogenous FA synthesis), and CVD. Genetic predisposition to higher plasma α-linolenic, linoleic, and oleic acid levels was associated with lower odds of large-artery stroke and venous thromboembolism, whereas higher arachidonic and stearic acid levels were associated with higher odds of these two CVDs. The associations were driven by SNPs in or close to FADS1. In the secondary analysis, the minor allele of rs174547 in FADS1 was associated with significantly lower odds of any ischemic stroke, large-artery stroke, and venous thromboembolism and showed suggestive evidence of inverse association with coronary artery disease, abdominal aortic aneurysm and aortic valve stenosis. Genetically higher plasma α-linolenic, linoleic, and oleic acid levels are inversely associated with large-artery stroke and venous thromboembolism, whereas arachidonic and stearic acid levels are positively associated with these CVDs. The associations were driven by FADS1, which was also associated with other CVDs.

Integrated UPLC-Q/TOF-MS Technique and MALDI-MS to Study of the Efficacy of YiXinshu Capsules Against Heart Failure in a Rat Model

Background: Yixinshu Capsules (YXSC) are widely used in Chinese medicine for the treatment of cardiovascular diseases. However, the therapeutic mechanisms of action are not well understood.

Method: In this study, a metabonomic approach based on integrated UPLC-Q/TOF-MS technique and MALDI-MS was utilized to explore potential metabolic biomarkers that may help increase the understanding of heart failure (HF) and in order to assess the potential mechanisms of YXSC against HF. Plasma metabolic profiles were analyzed by UPLC-Q/TOF-MS with complementary hydrophilic interaction chromatography and reversed-phase liquid chromatography. Moreover, time-course analysis at the 2nd, 4th, and 10th week after permanent occlusion was conducted. In an effort to identify a more reliable potential metabolic marker, common metabolic markers of the 2nd, 4th, and 10th week were selected through multivariate data analysis. Furthermore, MALDI-MS was applied to identify metabolic biomarkers in the blood at apoptotic positions of heart tissues.

Results: The results showed that HF appeared at the fourth week after permanent occlusion based on echocardiographic assessment. Clear separations were observed between the sham and model group by loading plots of orthogonal projection to latent structure discrimination analysis (OPLS-DA) at different time points after permanent occlusion. Potential markers of interest were extracted from the combining S-plots, variable importance for the projections values (VIP > 1), and t-test (p < 0.05). Twenty-one common metabolic markers over the course of the development and progression of HF after permanent occlusion were identified. These were determined to be mainly related to disturbances in fatty acids, phosphatidylcholine, bile acids, amino acid metabolism, and pyruvate metabolism. Of the metabolic markers, 16 metabolites such as palmitoleic acid, arachidonic acid, and lactic acid showed obvious changes (p < 0.05) and a tendency for returning to baseline values in YXSC-treated HF rats at the 10th week. Moreover, four biomarkers, including palmitoleic acid, palmitic acid, arachidonic, acid and lactic acid, were further validated at the apoptotic position of heart tissue using MALDI-MS, consistent to the variation trends in the plasma.

Conclusions: Taken in concert, our proposed strategy may contribute to the understanding of the complex pathogenesis of ischemia-induced HF and the potential mechanism of YXSC.

Serial Plasma Phospholipid Fatty Acids in the De Novo Lipogenesis Pathway and Total Mortality, Cause-Specific Mortality, and Cardiovascular Diseases in the Cardiovascular Health Study

Background Synthesized fatty acids (FAs) from de novo lipogenesis may affect cardiometabolic health, but longitudinal associations between serially measured de novo lipogenesis-related fatty acid biomarkers and mortality or cardiovascular disease (CVD) are not well established. Methods and Results We investigated longitudinal associations between de novo lipogenesis-related fatty acids with all-cause mortality, cause-specific mortality, and incident CVD among 3869 older US adults, mean (SD) age 75 (5) years and free of prevalent CVD at baseline. Levels of plasma phospholipid palmitic (16:0), palmitoleic (16:1n-7), stearic (18:0), oleic acid (18:1n-9), and other risk factors were serially measured at baseline, 6 years, and 13 years. All-cause mortality, cause-specific mortality, and incident fatal and nonfatal CVD were centrally adjudicated. Risk was assessed in multivariable-adjusted Cox models with time-varying FAs and covariates. During 13 years, median follow-up (maximum 22.4 years), participants experienced 3227 deaths (1131 CVD, 2096 non-CVD) and 1753 incident CVD events. After multivariable adjustment, higher cumulative levels of 16:0, 16:1n-7, and 18:1n-9 were associated with higher all-cause mortality, with extreme-quintile hazard ratios (95% CIs) of 1.35 (1.17-1.56), 1.40 (1.21-1.62), and 1.56 (1.35-1.80), respectively, whereas higher levels of 18:0 were associated with lower mortality (hazard ratio=0.76; 95% CI=0.66-0.88). Associations were generally similar for CVD mortality versus non-CVD mortality, as well as total incident CVD. Changes in levels of 16:0 were positively, and 18:0 inversely, associated with all-cause mortality (hazard ratio=1.23, 95% CI=1.08-1.41; and hazard ratio=0.78, 95% CI=0.68-0.90). Conclusions Higher long-term levels of 16:0, 16:1n-7, and 18:1n-9 and changes in 16:0 were positively, whereas long-term levels and changes in 18:0 were inversely, associated with all-cause mortality in older adults.

A Dietary Pattern Derived from Reduced Rank Regression and Fatty Acid Biomarkers Is Associated with Lower Risk of Type 2 Diabetes and Coronary Artery Disease in Chinese Adults

BACKGROUND

Combinations of circulating fatty acids may affect the risk of type 2 diabetes (T2D) and coronary artery disease (CAD). No previous studies have identified a dietary pattern predicting fatty acid profiles using reduced rank regression (RRR) and evaluated its associations with the risk of T2D and CAD.

OBJECTIVE

The aim of this study was to derive a dietary pattern to explain variation in plasma fatty acid concentrations using RRR and evaluate these in relation to risk of T2D and CAD.

METHODS

We derived a dietary pattern using fatty acid concentrations from 711 controls of a nested case-control study in the Singapore Chinese Health Study using RRR with 36 food and beverages as predictors and 19 fatty acid biomarkers as responses. Dietary pattern scores were then calculated for the full cohort of men and women (mean age: 56 y). We followed up 45,411 and 58,065 participants for incident T2D and CAD mortality, respectively. Multivariable Cox regression models were used to estimate HRs and 95% CIs.

RESULTS

We identified a dietary pattern high in soy, vegetables, fruits, tea, tomato products, bread, fish, margarine and dairy, and low in rice, red meat, coffee, alcohol, sugar-sweetened beverages, and eggs. This pattern predicted higher circulating n-3 (ω-3) PUFAs (18:3n-3, 20:3n-3, 20:5n-3), odd-chain fatty acids (15:0, 17:0), 18:2n-6 and 20:1, and lower 20:4n-6 and 16:1. During a mean follow-up of 11 y and 19 y, 5207 T2D and 3016 CAD mortality events, respectively, were identified. Higher dietary pattern scores were associated with a lower risk of T2D [multivariable-adjusted HR comparing extreme quintiles, 0.86 (95% CI: 0.79, 0.95); P-trend <0.001] and CAD mortality [HR, 0.76 (95% CI: 0.68, 0.86); P-trend <0.001].

CONCLUSIONS

Dietary patterns reflecting higher circulating n-3 PUFAs, odd-chain fatty acids, and linoleic acid may be associated with lower T2D and CAD risk in Chinese adults. This trial was registered at www.clinicaltrials.gov as NCT03356340.

Association between carbohydrate intake and fatty acids in the de novo lipogenic pathway in serum phospholipids and adipose tissue in a population of Swedish men

PURPOSE

Fatty acid composition in blood and adipose tissue (AT) is a useful biomarker of dietary fat quality. However, circulating saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) have been proposed to also reflect carbohydrate-induced de novo lipogenesis (DNL) and stearoyl-CoA desaturase (SCD) activity. We aimed to test the hypothesis that high carbohydrate intake is related to SFA and MUFA in serum or AT in a Swedish population.

METHODS

Fatty acid composition was measured in serum phospholipids (PL) and AT by gas chromatography in 63-year-old men (n = 299). Carbohydrate and alcohol intake was assessed (validated 7-day food records) in relation to total SFA, 16:0 (palmitate), 16:1 (palmitoleate), and estimated SCD activity (16:1n-7/16:0-ratio) in serum PL and in AT, respectively.

RESULTS

Total carbohydrate intake was inversely associated with 16:0 in PL (P = 0.005), independently of BMI. Disaccharides were non-linearly (restricted cubic splines) and weakly associated with 16:1 and SCD activity in PL (nonlinear trend, P ≤ 0.02) but not AT. Carbohydrate intake and SCD expression were not associated (P ≥ 0.08, n = 81). Alcohol intake was, however, linearly associated with 16:0 in PL (P < 0.001), and with 16:1 (P < 0.001) and SCD activity (P ≤ 0.005) in both PL and AT.

CONCLUSIONS

Higher carbohydrate intake from sugar-rich foods or beverages was not clearly reflected by higher SFA or SCD activity in serum PL or AT. Alcohol was, however, associated with higher SFA and MUFA.

Dietary carbohydrate restriction improves metabolic syndrome independent of weight loss

BACKGROUNDMetabolic syndrome (MetS) is highly correlated with obesity and cardiovascular risk, but the importance of dietary carbohydrate independent of weight loss in MetS treatment remains controversial. Here, we test the theory that dietary carbohydrate intolerance (i.e., the inability to process carbohydrate in a healthy manner) rather than obesity per se is a fundamental feature of MetS.METHODSIndividuals who were obese with a diagnosis of MetS were fed three 4-week weight-maintenance diets that were low, moderate, and high in carbohydrate. Protein was constant and fat was exchanged isocalorically for carbohydrate across all diets.RESULTSDespite maintaining body mass, low-carbohydrate (LC) intake enhanced fat oxidation and was more effective in reversing MetS, especially high triglycerides, low HDL-C, and the small LDL subclass phenotype. Carbohydrate restriction also improved abnormal fatty acid composition, an emerging MetS feature. Despite containing 2.5 times more saturated fat than the high-carbohydrate diet, an LC diet decreased plasma total saturated fat and palmitoleate and increased arachidonate.CONCLUSIONConsistent with the perspective that MetS is a pathologic state that manifests as dietary carbohydrate intolerance, these results show that compared with eucaloric high-carbohydrate intake, LC/high-fat diets benefit MetS independent of whole-body or fat mass.TRIAL REGISTRATIONClinicalTrials.gov Identifier: NCT02918422.FUNDINGDairy Management Inc. and the Dutch Dairy Association.

Oxylipins in triglyceride-rich lipoproteins of dyslipidemic subjects promote endothelial inflammation following a high fat meal

Elevated triglyceride-rich lipoproteins (TGRL) in circulation is a risk factor for atherosclerosis. TGRL from subjects consuming a high saturated fat test meal elicited a variable inflammatory response in TNFα-stimulated endothelial cells (EC) that correlated strongly with the polyunsaturated fatty acid (PUFA) content. This study investigates how the relative abundance of oxygenated metabolites of PUFA, oxylipins, is altered in TGRL postprandially, and how these changes promote endothelial inflammation. Human aortic EC were stimulated with TNFα and treated with TGRL, isolated from subjects’ plasma at fasting and 3.5 hrs postprandial to a test meal high in saturated fat. Endothelial VCAM-1 surface expression stimulated by TNFα provided a readout for atherogenic inflammation. Concentrations of esterified and non-esterified fatty acids and oxylipins in TGRL were quantified by mass spectrometry. Dyslipidemic subjects produced TGRL that increased endothelial VCAM-1 expression by ≥35%, and exhibited impaired fasting lipogenesis activity and a shift in soluble epoxide hydrolase and lipoxygenase activity. Pro-atherogenic TGRL were enriched in eicosapentaenoic acid metabolites and depleted in esterified C18-PUFA-derived diols. Abundance of these metabolites was strongly predictive of VCAM-1 expression. We conclude the altered metabolism in dyslipidemic subjects produces TGRL with a unique oxylipin signature that promotes a pro-atherogenic endothelial phenotype.

Polyunsaturated Fatty Acids and Glycemic Control in Type 2 Diabetes

The impact of dietary fat on the risk of cardiovascular disease (CVD) has been extensively studied in recent decades. Solid evidence indicates that replacing saturated fatty acids (SFAs) with polyunsaturated fatty acids (PUFAs) decreases blood cholesterol levels and prevents CVD and CVD mortality. Studies indicate that fat quality also may affect insulin sensitivity and hence, the risk of type 2 diabetes (T2D). A high intake of SFAs has shown to increase the risk of T2D in prospective studies, while a high intake of PUFAs reduces the risk. Whether PUFAs from marine or vegetable sources affect glycemic regulation differently in T2D remains to be elucidated. The aim of the present review was therefore to summarize research on human randomized, controlled intervention studies investigating the effect of dietary PUFAs on glycemic regulation in T2D. About half of the studies investigating the effect of fish, fish oils, vegetable oils, or nuts found changes related to glycemic control in people with T2D, while the other half found no effects. Even though some of the studies used SFA as controls, the majority of the included studies compared PUFAs of different quality. Considering that both marine and vegetable oils are high in PUFAs and hence both oils may affect glycemic regulation, the lack of effect in several of the included studies may be explained by the use of an inappropriate control group. It is therefore not possible to draw a firm conclusion, and more studies are needed.