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

Beyond Calories: Individual Metabolic and Hormonal Adaptations Driving Variability in Weight Management-A State-of-the-Art Narrative Review

The global rise in obesity underscores the need for effective weight management strategies that address individual metabolic and hormonal variability, moving beyond the simplistic "calories in, calories out" model. Body types-ectomorph, mesomorph, and endomorph-provide a framework for understanding the differences in fat storage, muscle development, and energy expenditure, as each type responds uniquely to caloric intake and exercise. Variability in weight outcomes is influenced by factors such as genetic polymorphisms and epigenetic changes in hormonal signaling pathways and metabolic processes, as well as lifestyle factors, including nutrition, exercise, sleep, and stress. These factors impact the magnitude of lipogenesis and myofibrillar protein synthesis during overfeeding, as well as the extent of lipolysis and muscle proteolysis during caloric restriction, through complex mechanisms that involve changes in the resting metabolic rate, metabolic pathways, and hormonal profiles. Precision approaches, such as nutrigenomics, indirect calorimetry, and artificial-intelligence-based strategies, can potentially leverage these insights to create individualized weight management strategies aligned with each person's unique metabolic profile. By addressing these personalized factors, precision nutrition offers a promising pathway to sustainable and effective weight management outcomes. The main objective of this review is to examine the metabolic and hormonal adaptations driving variability in weight management outcomes and explore how precision nutrition can address these challenges through individualized strategies.

Effects of coconut oil, olive oil, and butter on plasma fatty acids and metabolic risk factors: a randomized trial

There is limited evidence on the effects of different dietary sources of fats on detailed blood fatty acids (FAs). We aimed to evaluate the effects of coconut oil, olive oil and butter on circulating FA concentrations, and examine the associations between changes in plasma FAs and changes in metabolic markers. We conducted secondary analyses in the COB (coconut oil, olive oil and butter) Trial that evaluated 96 healthy adults in a 4-week parallel randomized clinical trial of three dietary interventions: 50 g/d of extra-virgin coconut oil (n = 30), extra-virgin olive oil (n = 33), or unsalted butter (n = 33). We measured plasma phospholipid FA concentrations (mol% of total) using gas chromatography. Using linear regression, we estimated the effects of the interventions on changes in FAs and the associations of changes in selected FAs with changes in metabolic markers. Coconut oil doubled lauric acid (C12:0) and myristic acid (C14:0), butter increased those to a lesser extent, and olive oil reduced those. β (95% confidence interval) for changes in C12:0 comparing coconut oil to butter and olive oil were +0.04 (0.03-0.05) and +0.05 (0.04-0.06) mol%, respectively; for C14:0, +0.24 (0.17-0.32) and +0.37 (0.29-0.45), respectively. Olive oil increased oleic acid (OA) approximately by 1 mol%, while coconut oil and butter had little effect on OA. Butter increased odd-chain SFAs and trans-FAs while olive oil and coconut oil decreased them. Changes in FAs mostly showed no significant associations with changes in metabolic markers. The interventions of equal amounts of different food FA sources altered circulating FA concentrations differently.

Association between Serum Fatty Acids Profile and MetScore in Women with Severe Obesity

BACKGROUND

Metabolic syndrome (MetS) is a set of conditions associated with an increased cardiovascular risk. Several serum fatty acids (FAs) seem to play an essential role in the development of cardiometabolic diseases and mortality. Thus, it is imperative to explore the impact of FAs on MetS parameters, using an early MetS screening tool such as MetScore, which is readily available in clinical practice.

AIM

The aim of this study was to assess the potential correlation between serum FAs and cardiovascular risk using a MetScore.

METHODS

This cross-sectional study involved 41 women with severe obesity. The MetScore was calculated, and participants were categorized into high- and low-cardiovascular-risk groups based on the median MetScore value. Gas chromatography was used to quantify serum FAs. Generalized Linear Models were used to compare group means. The association was assessed through simple logistic regression, and an adjusted logistic regression was conducted to validate the association between Metscore and serum FAs.

RESULTS

The high-cardiovascular-risk group exhibited elevated values of HOMA-IR, palmitic, oleic, cis-vaccenic, and monounsaturated fatty acids, as well as the SCD-18C, indicating a heightened cardiovascular risk. Conversely, HDL-c, QUICK, gamma-linolenic, and eicosatetraenoic fatty acids showed lower values compared to the low-risk group.

CONCLUSIONS

Women with severe obesity and high cardiovascular risk have lower values of some omega-3 and omega-6 FAs, considered cardioprotective and anti-inflammatory, and have higher lipogenic activity and FAs, correlated with high cardiovascular risk. These findings emphasize the need to address lipid metabolism in this population as a therapeutic target to reduce cardiovascular risk. Future research should explore clinical interventions that modulate fatty acid metabolism to mitigate cardiometabolic complications.

MRI assessment of adipose tissue fatty acid composition in the UK Biobank and its association with diet and disease

OBJECTIVE

This study aimed to assess the fatty acid (FA) composition of abdominal subcutaneous and visceral adipose tissue (ASAT and VAT, respectively) in the UK Biobank imaging cohort (N = 33,823) using magnetic resonance imaging (MRI).

METHODS

We measured the fractions of saturated, monounsaturated, and polyunsaturated FA (fSFA, fMUFA, and fPUFA, respectively) in ASAT and VAT from multiecho MRI scans. We selected a subcohort of participants who followed a vegan and an omnivore diet (N = 36) to validate the effect of diet on adipose tissue. In the wider imaging cohort, we examined the relationships between adipose tissue FA composition and various traits related to disease and body size.

RESULTS

We measured adipose tissue FA composition for over 33,000 participants, revealing higher fSFA and fPUFA and lower fMUFA in VAT (p < 0.00016). fMUFA and fPUFA were higher in ASAT and lower in VAT for women (p < 0.00016). Vegan participants exhibited lower fSFA in both ASAT and VAT (p < 0.00016). VAT fSFA and fMUFA showed significant associations with disease, as well as anthropometric variables.

CONCLUSIONS

This extensive analysis revealed the relationships between adipose tissue FA composition and a range of factors in a diverse population, highlighting the importance of studying body adipose tissue beyond its quantity.

The causal relationship between human blood metabolites and the risk of visceral obesity: a mendelian randomization analysis

BACKGROUND

We aimed to explore the causal relationship between blood metabolites and the risk of visceral obesity, as measured by visceral adipose tissue (VAT).

METHODS

Summary statistics for 486 blood metabolites and total, as well as sex-stratified, MRI-derived VAT measurements, adjusted for body mass index (BMI) and height, were collected from previous genome-wide association studies (GWAS). A two-sample Mendelian Randomization (MR) design was used. Comprehensive evaluation was further conducted, including sensitivity analysis, linkage disequilibrium score (LDSC) regression, Steiger test, and metabolic pathway analysis.

RESULTS

After multiple testing correction, arachidonate (20:4n6) has been implicated in VAT accumulation (β = 0.35, 95%CI:0.18-0.52, P < 0.001; FDR = 0.025). Additionally, several blood metabolites were identified as potentially having causal relationship (FDR < 0.10). Among them, lysine (β = 0.67, 95%CI: 0.28-1.06, P < 0.001; FDR = 0.074), proline (β = 0.30, 95%CI:0.13-0.48, P < 0.001; FDR = 0.082), valerate (β = 0.50, 95%CI:0.23-0.78, P < 0.001, FDR = 0.091) are associated with an increased risk of VAT accumulation. On the other hand, glycine (β=-0.21, 95%CI: -0.33-0.09), P < 0.001, FDR = 0.076) have a protective effect against VAT accumulation. Most blood metabolites showed consistent trends between different sexes. Multivariable MR analysis demonstrated the effect of genetically predicted arachidonate (20:4n6) and proline on VAT remained after accounting for BMI and glycated hemoglobin (HbA1c). There is no evidence of heterogeneity, pleiotropy, and reverse causality.

CONCLUSION

Our MR findings suggest that these metabolites may serve as biomarkers, as well as for future mechanistic exploration and drug target selection of visceral obesity.

Plasma fatty acid composition and some markers of dietary habits are associated with cardiovascular disease risk determined by an atherogenic plasma index in postmenopausal women

It is hypothesized that plasma proportion of selected fatty acids (FAs) and dietary habits are linked with the risk of cardiovascular disease (CVD) in postmenopausal women. Therefore, this study was designed to determine the association of plasma FA composition and markers of dietary habits with an atherogenic index of plasma (AIP), a predictor of CVD risk in postmenopausal women. In total, 87 postmenopausal women with an average age of 57 ± 7 years were recruited and their dietary intake, anthropometric and biochemical parameters, and FA status in total plasma lipid proportions were determined, showing that 65.5% of the participants had a high risk of CVD according to their AIP value. After adjusting for some confounders (age, body mass index, and physical activity level), the risk of CVD was only positively associated with the frequency of consumption of animal fat spreads (butter and lard) of terrestrial origin. Regarding the FA profile, CVD risk was positively associated with the percentages of vaccenic acid, dihomo-γ-linolenic acid, and monounsaturated fatty acids (MUFA; mainly n-7) in total FA, as well as the MUFA/SFA ratio in total plasma and stearoyl-CoA desaturase-16 activity (16:1/16:0 ratio). In contrast, the risk of CVD was negatively associated with percentages of α-linolenic acid, total polyunsaturated fatty acids (PUFA), and PUFA/MUFA ratio in total plasma lipid, and the estimated activity of Δ5-desaturase (20:4/20:3 n-6 ratio). These results support the current recommendations to decrease the frequency of animal fat spread intake because it is associated with a reduced CVD risk based on AIP in postmenopausal women. In accordance with these plasma percentages of ALA, vaccenic acid, dihomo-γ-linolenic acid, PUFA, PUFA/MUFA ratio, and 16:1/16:0 ratio may be important parameters in CVD risk assessment.

Targeting the Inflammatory Hallmarks of Obesity-Associated Osteoarthritis: Towards Nutraceutical-Oriented Preventive and Complementary Therapeutic Strategies Based on n-3 Polyunsaturated Fatty Acids

Obesity (Ob), which has dramatically increased in the last decade, is one of the main risk factors that contribute to the incidence and progression of osteoarthritis (OA). Targeting the characteristics of obesity-associated osteoarthritis (ObOA) may offer new chances for precision medicine strategies in this patient cohort. First, this review outlines how the medical perspective of ObOA has shifted from a focus on biomechanics to the significant contribution of inflammation, mainly mediated by changes in the adipose tissue metabolism through the release of adipokines and the modification of fatty acid (FA) compositions in joint tissues. Preclinical and clinical studies on n-3 polyunsaturated FAs (PUFAs) are critically reviewed to outline the strengths and weaknesses of n-3 PUFAs' role in alleviating inflammatory, catabolic and painful processes. Emphasis is placed on potential preventive and therapeutic nutritional strategies based on n-3 PUFAs, with a focus on ObOA patients who could specifically benefit from reformulating the dietary composition of FAs towards a protective phenotype. Finally, tissue engineering approaches that involve the delivery of n-3 PUFAs directly into the joint are explored to address the perspectives and current limitations, such as safety and stability issues, for implementing preventive and therapeutic strategies based on dietary compounds in ObOA patients.

Impact of a food-based dietary fat exchange model for replacing dietary saturated with unsaturated fatty acids in healthy men on plasma phospholipids fatty acid profiles and dietary patterns

PURPOSE

UK guidelines recommend dietary saturated fatty acids (SFAs) should not exceed 10% total energy (%TE) for cardiovascular disease prevention, with benefits observed when SFAs are replaced with unsaturated fatty acids (UFAs). This study aimed to assess the efficacy of a dietary exchange model using commercially available foods to replace SFAs with UFAs.

METHODS

Healthy men (n = 109, age 48, SD 11 year) recruited to the Reading, Imperial, Surrey, Saturated fat Cholesterol Intervention-1 (RISSCI-1) study (ClinicalTrials.Gov n°NCT03270527) followed two sequential 4-week isoenergetic moderate-fat (34%TE) diets: high-SFA (18%TE SFAs, 16%TE UFAs) and low-SFA (10%TE SFAs, 24%TE UFAs). Dietary intakes were assessed using 4-day weighed diet diaries. Nutrient intakes were analysed using paired t-tests, fasting plasma phospholipid fatty acid (PL-FA) profiles and dietary patterns were analysed using orthogonal partial least square discriminant analyses.

RESULTS

Participants exchanged 10.2%TE (SD 4.1) SFAs for 9.7%TE (SD 3.9) UFAs between the high and low-SFA diets, reaching target intakes with minimal effect on other nutrients or energy intakes. Analyses of dietary patterns confirmed successful incorporation of recommended foods from commercially available sources (e.g. dairy products, snacks, oils, and fats), without affecting participants' overall dietary intakes. Analyses of plasma PL-FAs indicated good compliance to the dietary intervention and foods of varying SFA content.

CONCLUSIONS

RISSCI-1 dietary exchange model successfully replaced dietary SFAs with UFAs in free-living healthy men using commercially available foods, and without altering their dietary patterns. Further intervention studies are required to confirm utility and feasibility of such food-based dietary fat replacement models at a population level.

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].

Lipophagy mediated glucose-induced changes of lipid deposition and metabolism via ROS dependent AKT-Beclin1 activation

High dietary carbohydrate intake leads to lipid accumulation in the intestinal tract, but the molecular mechanism remains unknown. In the present study, using yellow catfish (Pelteobagrus fulvidraco) as a model, we found that (1) high carbohydrate diets (HCD) and high glucose (HG) increased lipid deposition, up-regulated lipogenesis and fatty acid β-oxidation, activated autophagy and induced oxidative stress in the intestinal tissues and intestinal epithelial cells (IECs); (2) lipophagy alleviated HG-induced lipid accumulation via the up-regulation of fatty acid β-oxidation; (3) Akt interacted directly with Beclin1; (4) HG suppressed Akt1 phosphorylation, downregulated Akt1-mediated phosphorylation of Beclin1, activated lipophagy and alleviated the increment of TG deposition induced by HG with S87 and S292 being the key phosphorylation residues of Beclin1 in response to HG; (5) ROS generation mediated HG-induced activation of lipophagy and HG-induced suppression of AKT phosphorylation, activated AMPK and alleviated HG-induced increase of TG deposition. Our study provides mechanistic evidence that high carbohydrate- and glucose-induced lipophagy in intestine and IECs is associated with ROS-AKT-Beclin1-dependent activation of autophagy, which alleviates glucose-induced lipid accumulation. Our findings are important since the regulation of autophagy can be used as potential molecular targets for the prevention and treatment of lipotoxicity in the intestine of vertebrates, including humans.

Low Levels of Omega-3 Long-Chain Polyunsaturated Fatty Acids Are Associated with Bone Metastasis Formation in Premenopausal Women with Breast Cancer: A Retrospective Study

In the present study, we investigated various biochemical, clinical, and histological factors associated with bone metastases in a large cohort of pre- and postmenopausal women with breast cancer. Two hundred and sixty-one consecutive women with breast cancer were included in this study. Breast adipose tissue specimens were collected during surgery. After having established the fatty acid profile of breast adipose tissue by gas chromatography, we determined whether there were differences associated with the occurrence of bone metastases in these patients. Regarding the clinical and histological criteria, a majority of the patients with bone metastases (around 70%) had tumors with a luminal phenotype and 59% of them showed axillary lymph node involvement. Moreover, we found a negative association between the levels of n-3 long-chain polyunsaturated fatty acids (LC-PUFA) in breast adipose tissue and the development of bone metastases in premenopausal women. No significant association was observed in postmenopausal women. In addition to a luminal phenotype and axillary lymph node involvement, low levels of n-3 LC-PUFA in breast adipose tissue may constitute a risk factor that contributes to breast cancer bone metastases formation in premenopausal women.

Fatty acids in the de novo lipogenesis pathway and incidence of type 2 diabetes: A pooled analysis of prospective cohort studies

BACKGROUND

De novo lipogenesis (DNL) is the primary metabolic pathway synthesizing fatty acids from carbohydrates, protein, or alcohol. Our aim was to examine associations of in vivo levels of selected fatty acids (16:0, 16:1n7, 18:0, 18:1n9) in DNL with incidence of type 2 diabetes (T2D).

METHODS AND FINDINGS

Seventeen cohorts from 12 countries (7 from Europe, 7 from the United States, 1 from Australia, 1 from Taiwan; baseline years = 1970-1973 to 2006-2010) conducted harmonized individual-level analyses of associations of DNL-related fatty acids with incident T2D. In total, we evaluated 65,225 participants (mean ages = 52.3-75.5 years; % women = 20.4%-62.3% in 12 cohorts recruiting both sexes) and 15,383 incident cases of T2D over the 9-year follow-up on average. Cohort-specific association of each of 16:0, 16:1n7, 18:0, and 18:1n9 with incident T2D was estimated, adjusted for demographic factors, socioeconomic characteristics, alcohol, smoking, physical activity, dyslipidemia, hypertension, menopausal status, and adiposity. Cohort-specific associations were meta-analyzed with an inverse-variance-weighted approach. Each of the 4 fatty acids positively related to incident T2D. Relative risks (RRs) per cohort-specific range between midpoints of the top and bottom quintiles of fatty acid concentrations were 1.53 (1.41-1.66; p < 0.001) for 16:0, 1.40 (1.33-1.48; p < 0.001) for 16:1n-7, 1.14 (1.05-1.22; p = 0.001) for 18:0, and 1.16 (1.07-1.25; p < 0.001) for 18:1n9. Heterogeneity was seen across cohorts (I2 = 51.1%-73.1% for each fatty acid) but not explained by lipid fractions and global geographical regions. Further adjusted for triglycerides (and 16:0 when appropriate) to evaluate associations independent of overall DNL, the associations remained significant for 16:0, 16:1n7, and 18:0 but were attenuated for 18:1n9 (RR = 1.03, 95% confidence interval (CI) = 0.94-1.13). These findings had limitations in potential reverse causation and residual confounding by imprecisely measured or unmeasured factors.

CONCLUSIONS

Concentrations of fatty acids in the DNL were positively associated with T2D incidence. Our findings support further work to investigate a possible role of DNL and individual fatty acids in the development of T2D.