Reduction in saturated fat intake for cardiovascular disease

Effects of dietary fat sources on the intramuscular and subcutaneous adipose tissue fatty acid composition, and consumer acceptability of lamb

BACKGROUND

Lamb diets can alter the fatty acid (FA) profile of muscle and adipose tissue, which may affect the sensory quality and consumer acceptability of the meat. In this study, lambs received one of four pre-slaughter diets: a barley / maize / soya-based concentrate (C), supplemented with a saturated fat source (Megalac®) (SAT), or supplemented with protected linseed oil (PLO); or a by-product (citrus pulp / distillers' grain / soya-based) diet (BPR). Intramuscular FAs and adipose tissue branched-chain FAs were measured and consumer evaluation (hedonic liking and attribute intensity) was undertaken with cooked lamb.

RESULTS

Compared to the other diets, the BPR diet resulted in a higher muscle concentration and a greater proportion of C18:2n-6, and greater proportions of conjugated linoleic acid (c9,t11-C18:2) and n-6 polyunsaturated FAs (PUFA), whereas the PLO diet resulted in higher muscle proportions of C18:0 and saturated FAs, higher concentrations of C18:3n-3 and n-3 PUFA, and a lower n-6 to n-3 ratio. The consumer acceptability of lamb was not affected by the pre-slaughter diets.

CONCLUSION

Changes in the FA profile of lamb muscle and adipose tissue through the inclusion of sources of saturated fat, protected linseed oil, or by-products in the pre-slaughter diet did not result in consumer detection of significant effects on the acceptability of the cooked meat. © 2020 Society of Chemical Industry.

Circulating Fatty Acids and Risk of Coronary Heart Disease and Stroke: Individual Participant Data Meta-Analysis in Up to 16 126 Participants

Background We aimed at investigating the association of circulating fatty acids with coronary heart disease (CHD) and stroke risk. Methods and Results We conducted an individual-participant data meta-analysis of 5 UK-based cohorts and 1 matched case-control study. Fatty acids (ie, omega-3 docosahexaenoic acid, omega-6 linoleic acid, monounsaturated and saturated fatty acids) were measured at baseline using an automated high-throughput serum nuclear magnetic resonance metabolomics platform. Data from 3022 incident CHD cases (13 104 controls) and 1606 incident stroke cases (13 369 controls) were included. Logistic regression was used to model the relation between fatty acids and odds of CHD and stroke, adjusting for demographic and lifestyle variables only (ie, minimally adjusted model) or with further adjustment for other fatty acids (ie, fully adjusted model). Although circulating docosahexaenoic acid, but not linoleic acid, was related to lower CHD risk in the fully adjusted model (odds ratio, 0.85; 95% CI, 0.76-0.95 per standard unit of docosahexaenoic acid), there was evidence of high between-study heterogeneity and effect modification by study design. Stroke risk was consistently lower with increasing circulating linoleic acid (odds ratio for fully adjusted model, 0.82; 95% CI, 0.75-0.90). Circulating monounsaturated fatty acids were associated with higher CHD risk across all models and with stroke risk in the fully adjusted model (odds ratio, 1.22; 95% CI, 1.03-1.44). Saturated fatty acids were not related to increased CHD risk in the fully adjusted model (odds ratio, 0.94; 95% CI, 0.82-1.09), or stroke risk. Conclusions We found consistent evidence that linoleic acid was associated with decreased risk of stroke and that monounsaturated fatty acids were associated with increased risk of CHD. The different pattern between CHD and stroke in terms of fatty acids risk profile suggests future studies should be cautious about using composite events. Different study designs are needed to assess which, if any, of the associations observed is causal.

Omega-3 fatty acids for the primary and secondary prevention of cardiovascular disease

BACKGROUND

Omega-3 polyunsaturated fatty acids from oily fish (long-chain omega-3 (LCn3)), including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)), as well as from plants (alpha-linolenic acid (ALA)) may benefit cardiovascular health. Guidelines recommend increasing omega-3-rich foods, and sometimes supplementation, but recent trials have not confirmed this.

OBJECTIVES

To assess the effects of increased intake of fish- and plant-based omega-3 fats for all-cause mortality, cardiovascular events, adiposity and lipids.

SEARCH METHODS

We searched CENTRAL, MEDLINE and Embase to February 2019, plus ClinicalTrials.gov and World Health Organization International Clinical Trials Registry to August 2019, with no language restrictions. We handsearched systematic review references and bibliographies and contacted trial authors.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that lasted at least 12 months and compared supplementation or advice to increase LCn3 or ALA intake, or both, versus usual or lower intake.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion, extracted data and assessed validity. We performed separate random-effects meta-analysis for ALA and LCn3 interventions, and assessed dose-response relationships through meta-regression.

MAIN RESULTS

We included 86 RCTs (162,796 participants) in this review update and found that 28 were at low summary risk of bias. Trials were of 12 to 88 months' duration and included adults at varying cardiovascular risk, mainly in high-income countries. Most trials assessed LCn3 supplementation with capsules, but some used LCn3- or ALA-rich or enriched foods or dietary advice compared to placebo or usual diet. LCn3 doses ranged from 0.5 g a day to more than 5 g a day (19 RCTs gave at least 3 g LCn3 daily). Meta-analysis and sensitivity analyses suggested little or no effect of increasing LCn3 on all-cause mortality (risk ratio (RR) 0.97, 95% confidence interval (CI) 0.93 to 1.01; 143,693 participants; 11,297 deaths in 45 RCTs; high-certainty evidence), cardiovascular mortality (RR 0.92, 95% CI 0.86 to 0.99; 117,837 participants; 5658 deaths in 29 RCTs; moderate-certainty evidence), cardiovascular events (RR 0.96, 95% CI 0.92 to 1.01; 140,482 participants; 17,619 people experienced events in 43 RCTs; high-certainty evidence), stroke (RR 1.02, 95% CI 0.94 to 1.12; 138,888 participants; 2850 strokes in 31 RCTs; moderate-certainty evidence) or arrhythmia (RR 0.99, 95% CI 0.92 to 1.06; 77,990 participants; 4586 people experienced arrhythmia in 30 RCTs; low-certainty evidence). Increasing LCn3 may slightly reduce coronary heart disease mortality (number needed to treat for an additional beneficial outcome (NNTB) 334, RR 0.90, 95% CI 0.81 to 1.00; 127,378 participants; 3598 coronary heart disease deaths in 24 RCTs, low-certainty evidence) and coronary heart disease events (NNTB 167, RR 0.91, 95% CI 0.85 to 0.97; 134,116 participants; 8791 people experienced coronary heart disease events in 32 RCTs, low-certainty evidence). Overall, effects did not differ by trial duration or LCn3 dose in pre-planned subgrouping or meta-regression. There is little evidence of effects of eating fish. Increasing ALA intake probably makes little or no difference to all-cause mortality (RR 1.01, 95% CI 0.84 to 1.20; 19,327 participants; 459 deaths in 5 RCTs, moderate-certainty evidence),cardiovascular mortality (RR 0.96, 95% CI 0.74 to 1.25; 18,619 participants; 219 cardiovascular deaths in 4 RCTs; moderate-certainty evidence), coronary heart disease mortality (RR 0.95, 95% CI 0.72 to 1.26; 18,353 participants; 193 coronary heart disease deaths in 3 RCTs; moderate-certainty evidence) and coronary heart disease events (RR 1.00, 95% CI 0.82 to 1.22; 19,061 participants; 397 coronary heart disease events in 4 RCTs; low-certainty evidence). However, increased ALA may slightly reduce risk of cardiovascular disease events (NNTB 500, RR 0.95, 95% CI 0.83 to 1.07; but RR 0.91, 95% CI 0.79 to 1.04 in RCTs at low summary risk of bias; 19,327 participants; 884 cardiovascular disease events in 5 RCTs; low-certainty evidence), and probably slightly reduces risk of arrhythmia (NNTB 91, RR 0.73, 95% CI 0.55 to 0.97; 4912 participants; 173 events in 2 RCTs; moderate-certainty evidence). Effects on stroke are unclear. Increasing LCn3 and ALA had little or no effect on serious adverse events, adiposity, lipids and blood pressure, except increasing LCn3 reduced triglycerides by ˜15% in a dose-dependent way (high-certainty evidence).

AUTHORS' CONCLUSIONS

This is the most extensive systematic assessment of effects of omega-3 fats on cardiovascular health to date. Moderate- and low-certainty evidence suggests that increasing LCn3 slightly reduces risk of coronary heart disease mortality and events, and reduces serum triglycerides (evidence mainly from supplement trials). Increasing ALA slightly reduces risk of cardiovascular events and arrhythmia.

Optimum nutritional strategies for cardiovascular disease prevention and rehabilitation (BACPR)

Nutrition has a central role in both primary and secondary prevention of cardiovascular disease yet only relatively recently has food been regarded as a treatment, rather than as an adjunct to established medical and pharmacotherapy. As a field of research, nutrition science is constantly evolving making it difficult for patients and practitioners to ascertain best practice. This is compounded further by the inherent difficulties in performing double-blind randomised controlled trials. This paper covers dietary patterns that are associated with improved cardiovascular outcomes, including the Mediterranean Diet but also low-carbohydrate diets and the potential issues encountered with their implementation. We suggest there must be a refocus away from macronutrients and consideration of whole foods when advising individuals. This approach is fundamental to practice, as clinical guidelines have focused on macronutrients without necessarily considering their source, and ultimately people consume foods containing multiple nutrients. The inclusion of food-based recommendations aids the practitioner to help the patient make genuine and meaningful changes in their diet. We advocate that the cardioprotective diet constructed around the traditional Mediterranean eating pattern (based around vegetables and fruits, nuts, legumes, and unrefined cereals, with modest amounts of fish and shellfish, and fermented dairy products) is still important. However, there are other approaches that can be tried, including low-carbohydrate diets. We encourage practitioners to adopt a flexible dietary approach, being mindful of patient preferences and other comorbidities that may necessitate deviations away from established advice, and advocate for more dietitians in this field to guide the multi-professional team.

Mixed methods pilot study of a low-carbohydrate diabetes prevention programme among adults with pre-diabetes in the USA

OBJECTIVES

(1) To estimate weight change from a low-carbohydrate diabetes prevention programme (LC-DPP) and (2) to evaluate the feasibility and acceptability of an LC-DPP.

RESEARCH DESIGN

Single-arm, mixed methods (ie, integration of quantitative and qualitative data) pilot study.

SETTING

Primary care clinic within a large academic medical centre in the USA.

PARTICIPANTS

Adults with pre-diabetes and Body Mass Index of ≥25 kg/m².

INTERVENTION

We adapted the Centers for Disease Control and Prevention's National Diabetes Prevention Program (NDPP)-an evidence-based, low-fat dietary intervention-to teach participants to follow a very low-carbohydrate diet (VLCD). Participants attended 23 group-based classes over 1 year.

OUTCOME MEASURES

Primary outcome measures were (1) weight change and (2) percentage of participants who achieved ≥5% wt loss. Secondary outcome measures included intervention feasibility and acceptability (eg, attendance and qualitative interview feedback).

RESULTS

Our enrolment target was 22. One person dropped out before a baseline weight was obtained; data from 21 individuals were analysed. Mean weight loss in kilogram was 4.3 (SD 4.8) at 6 months and 4.9 (SD 5.8) at 12 months. Mean per cent body weight changes were 4.5 (SD 5.0) at 6 months and 5.2 (SD 6.0) at 12 months; 8/21 individuals (38%) achieved ≥5% wt loss at 12 months. Mean attendance was 10.3/16 weekly sessions and 3.4/7 biweekly or monthly sessions. Among interviewees (n=14), three factors facilitated VLCD adherence: (1) enjoyment of low-carbohydrate foods, (2) diminished hunger and cravings and (3) health benefits beyond weight loss. Three factors hindered VLCD adherence: (1) enjoyment of high-carbohydrate foods, (2) lack of social support and (3) difficulty preplanning meals.

CONCLUSIONS

An LC-DPP is feasible, acceptable and may be an effective option to help individuals with pre-diabetes to lose weight. Data from this pilot will be used to plan a fully powered randomised controlled trial of weight loss among NDPP versus LC-DPP participants.

TRIAL REGISTRATION NUMBER

NCT03258918.

Dietary Research on Coffee: Improving Adjustment for Confounding

Meta-analyses have reported higher levels of coffee consumption to be associated with lower mortality. In contrast, some systematic reviews have linked coffee consumption to increased risks for lung cancer and hypertension. Given these inconsistencies, this narrative review critically evaluated the methods and analyses of cohort studies investigating coffee and mortality. A specific focus was adjustment for confounding related to smoking, healthy and unhealthy foods, and alcohol. Assessment of 36 cohort samples showed that many did not adequately adjust for smoking. Consuming 1-5 cups of coffee per day was related to lower mortality among never smokers, in studies that adjusted for pack-years of smoking, and in studies adjusting for healthy and unhealthy foods. Possible reduced health benefits for coffee with added sugar have not been adequately investigated. Research on coffee and health should report separate analyses for never smokers, adjust for consumption of healthy and unhealthy foods, and for sugar added to coffee.

Dietary saturated fat and heart disease: a narrative review

The American Heart Association (AHA) recently published a meta-analysis that confirmed their 60-year-old recommendation to limit saturated fat (SFA, saturated fatty acid) and replace it with polyunsaturated fat to reduce the risk of heart disease based on the strength of 4 Core Trials. To assess the evidence for this recommendation, meta-analyses on the effect of SFA consumption on heart disease outcomes were reviewed. Nineteen meta-analyses addressing this topic were identified: 9 observational studies and 10 randomized controlled trials. Meta-analyses of observational studies found no association between SFA intake and heart disease, while meta-analyses of randomized controlled trials were inconsistent but tended to show a lack of an association. The inconsistency seems to have been mediated by the differing clinical trials included. For example, the AHA meta-analysis only included 4 trials (the Core Trials), and those trials contained design and methodological flaws and did not meet all the predefined inclusion criteria. The AHA stance regarding the strength of the evidence for the recommendation to limit SFAs for heart disease prevention may be overstated and in need of reevaluation.

Nutritional and other health properties of olive pomace oil

Olive-pomace oil is rich in oleic acid, and thus it can be an interesting dietary fat alternative as it can allow reaching the recommendation of consuming 20% of total diet energy in the form of monounsaturated fatty acids. In addition, olive-pomace oil also contains a wide range of minor components that may contribute to its healthy properties. The major components identified with healthy properties are triterpenic dialcohols and acids, squalene, tocopherols, sterols, fatty alcohols and phenolic compounds. The refining process, that the crude pomace-oil must undergo for commercial purposes, significantly reduces the content of phenolic compounds, while the other minor components remain at concentrations which can induce positive health effects, especially on cardiovascular health, outstanding pentacyclic triterpenes and aliphatic fatty alcohols in olive-pomace oil. Numerous in vitro and preclinical studies support that mainly the pure compounds, or extracts isolated from plant sources, play an important role in preventing cardiovascular disease and risk factors. Likewise, tocopherols, squalene and phytosterols, in addition to the minor fraction of phenolic compounds, have shown high biological activity with particular association to the cardiovascular function. In the light of the foregoing, and taking into consideration the absence of clinical studies with olive-pomace oil, it would be of great interest to develop randomized, crossover, controlled, double-blind studies to extend the knowledge and understanding on the health effects of olive-pomace olive.

Nutrient Composition of Popularly Consumed African and Caribbean Foods in The UK

(1) Background: Traditional foods are important in the diets of Black Africans and Caribbeans and, more widely, influence UK food culture. However, little is known about the nutritional status of these ethnic groups and the nutrient composition of their traditional foods. The aim was to identify and analyse African and Caribbean dishes, snacks and beverages popularly consumed in the UK for energy, macronutrients and micronutrients. (2) Methods: Various approaches including focus group discussions and 24-h dietary recalls were used to identify traditional dishes, snacks, and beverages. Defined criteria were used to prioritise and prepare 33 composite samples for nutrient analysis in a UK accredited laboratory. Quality assurance procedures and data verification were undertaken to ensure inclusion in the UK nutrient database. (3) Results: Energy content ranged from 60 kcal in Malta drink to 619 kcal in the shito sauce. Sucrose levels did not exceed the UK recommendation for adults and children. Most of the dishes contained negligible levels of trans fatty acid. The most abundant minerals were Na, K, Ca, Cu, Mn and Se whereas Mg, P, Fe and Zn were present in small amounts. (4) Conclusion: There was wide variation in the energy, macro- and micronutrients composition of the foods analysed.

Association between Macronutrient Intake and Excessive Daytime Sleepiness: An Iso-Caloric Substitution Analysis from the North West Adelaide Health Study

Epidemiological evidence on the association between macronutrient intake and excessive daytime sleepiness (EDS) is scarce. Using data from the North West Adelaide Health Study, we aimed to determine the association between iso-caloric substitution of macronutrients and EDS. Data from 1997 adults aged ≥ 24 years were analyzed. Daytime sleepiness was measured using the Epworth Sleepiness Scale, a score ≥ 11 was considered EDS. Dietary intake data were collected using a food frequency questionnaire. We determined absolute and relative energy intake based on consumption of saturated and unsaturated fats, protein, and carbohydrate. Odds ratios (ORs) were used to determine the associations using log-binomial logistic regression with and without iso-caloric substitution methods, and models were adjusted for confounders. The prevalence of EDS in the sample was 10.6%. After adjusting for potential confounders, substituting 5% energy intake from protein with an equal amount of saturated fat (OR = 1.57; 95% CI: 1.00–2.45) and carbohydrate (OR = 1.23; 95% CI: 0.92–1.65) increased the odds of EDS. When carbohydrate was substituted with saturated fat (OR = 1.27; 95% CI: 0.93–1.59), the odds of EDS were increased. The odds of EDS were lower when saturated fat was substituted with unsaturated fat (OR = 0.74; 95% CI: 0.51–1.06), protein (OR = 0.63; 95% CI: 0.41–0.99) or carbohydrate (OR = 0.79; 95% CI: 0.57–1.08). While these results were consistent over different iso-caloric substitution methods, inconsistent results were found with standard regression. While substitution of fat and carbohydrate with protein was inversely associated with EDS, substitution of protein with fat and carbohydrate was positively associated with EDS. Randomized trials are needed to confirm if dietary interventions can be used to improve daytime alertness in those with EDS.

Overview of Meta-Analyses: The Impact of Dietary Lifestyle on Stroke Risk

A stroke is one of the most prevalent cardiovascular diseases worldwide, both in high-income countries and in medium and low-medium income countries. The World Health Organization's (WHO) report on non-communicable diseases (NCDs) indicates that the highest behavioral risk in NCDs is attributable to incorrect nutrition. The objective of our work is to present an overview of meta-analyses that have investigated the impact of different foods and/or drinks in relationship with the risk of stroke events (ischemic/hemorrhagic). The papers to be included in the overview were found in MEDLINE, EMBASE, Scopus, Clinicaltrials.gov, Web of Science, and Cochrane Library and were selected according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) flow chart. Quality assessment were made according to the AMSTAR 2 scale. This overview shows that all primary studies came from countries with high income levels. This evidence shows that many countries are not represented. Therefore, different lifestyles, ethnic groups, potentially harmful or virtuous eating habits are not reported. It is important to underline how the choose of foods may help reduce the risk of cardiovascular diseases and stroke in particular.

Dietary Supplementation with Hazelnut Oil Reduces Serum Hyperlipidemia and Ameliorates the Progression of Nonalcoholic Fatty Liver Disease in Hamsters Fed a High-Cholesterol Diet

Objective: Hazelnut oil (HO) is rich in monounsaturated fatty acids and polyunsaturated fatty acids. This study intended to analyze the effects of hazelnut oil supplementation on the serum lipid profile and nonalcoholic fatty liver disease in hamsters fed a high-cholesterol (HC) diet. Methods: Hamsters were fed a basic diet (control group) and an HC diet (HC group) for 16 weeks (n = 10 in each group). Hamsters were fed an HC diet for four weeks to induce hyperlipidemia and were then fed an HC diet enriched with 5% (low-dose HC + HO group; n = 10) and 10% HO (high-dose HC + HO group; n = 10) for 12 weeks. Serum lipid levels, hepatic changes (including steatosis, inflammation, and fibrosis), and hepatic prooxidant-antioxidant status (malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPx), and glutathione S-transferase (GST)) were evaluated after the treatment period. Results: Hamsters in the control group showed normal serum lipid profiles, normal liver function, and moderate glycogen storage without hepatic steatosis. Hamsters in the HC group showed severe hyperlipidemia, severe hepatic steatosis, and moderate steatohepatitis (mononuclear cell and neutrophil infiltration, oval cell hyperplasia, and fibrosis). Compared to the HC group, both the low-dose and the high-dose HC + HO groups showed a significant reduction of hyperlipidemia (serum triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and very-low-density lipoprotein cholesterol (VLDL-C levels)) and improved liver function (serum glutamic-oxaloacetic transaminase (SGOT) and serum glutamic pyruvic transaminase (SGPT)). Additionally, compared to the HC group, intrahepatic triglyceride accumulation (IHTC) was significantly higher in the HC + HO group, while the incidence of steatohepatitis was significantly lower. The intake of the HC diet was associated with a higher level of lipid peroxidation (malondialdehyde, MDA) and a lower concentration of hepatic antioxidant enzymes (SOD, GPx, and GST), and all these factors were partially improved in the low-dose and high-dose HC + HO groups. Conclusions: Our findings indicate that the intake of HO reduced serum hyperlipidemia and oxidative stress and ameliorated the progression of nonalcoholic fatty liver disease in hamsters fed a high-cholesterol diet.

Effects of Full-Fat and Fermented Dairy Products on Cardiometabolic Disease: Food Is More Than the Sum of Its Parts

Current dietary recommendations to limit consumption of saturated fat are largely based on early nutrition studies demonstrating a direct link between dietary saturated fat, elevated blood cholesterol levels, and increased risk of cardiovascular disease. As full-fat dairy products are rich in saturated fat, these dietary guidelines recommend consumption of fat-free or low-fat dairy products in place of full-fat dairy. However, dairy products vary greatly in both their nutrient content and their bioactive ingredients, and research increasingly highlights the importance of focusing on whole foods (i.e., the food matrix) as opposed to single nutrients, such as saturated fat. In fact, the weight of evidence from recent large and well-controlled studies, systematic reviews, and meta-analyses of both observational studies and randomized controlled trials indicates that full-fat dairy products, particularly yogurt and cheese, do not exert the detrimental effects on insulin sensitivity, blood lipid profile, and blood pressure as previously predicted on the basis of their sodium and saturated fat contents; they do not increase cardiometabolic disease risk and may in fact protect against cardiovascular disease and type 2 diabetes. Although more research is warranted to adjust for possible confounding factors and to better understand the mechanisms of action of dairy products on health outcomes, it becomes increasingly clear that the recommendation to restrict dietary saturated fat to reduce risk of cardiometabolic disease is getting outdated. Therefore, the suggestion to restrict or eliminate full-fat dairy from the diet may not be the optimal strategy for reducing cardiometabolic disease risk and should be re-evaluated in light of recent evidence.

Implementation of a Brazilian Cardioprotective Nutritional (BALANCE) Program for improvement on quality of diet and secondary prevention of cardiovascular events: A randomized, multicenter trial

BACKGROUND

Appropriate dietary recommendations represent a key part of secondary prevention in cardiovascular disease (CVD). We evaluated the effectiveness of the implementation of a nutritional program on quality of diet, cardiovascular events, and death in patients with established CVD.

METHODS

In this open-label, multicenter trial conducted in 35 sites in Brazil, we randomly assigned (1:1) patients aged 45 years or older to receive either the BALANCE Program (experimental group) or conventional nutrition advice (control group). The BALANCE Program included a unique nutritional education strategy to implement recommendations from guidelines, adapted to the use of affordable and regional foods. Adherence to diet was evaluated by the modified Alternative Healthy Eating Index. The primary end point was a composite of all-cause mortality, cardiovascular death, cardiac arrest, myocardial infarction, stroke, myocardial revascularization, amputation, or hospitalization for unstable angina. Secondary end points included biochemical and anthropometric data, and blood pressure levels.

RESULTS

From March 5, 2013, to Abril 7, 2015, a total of 2534 eligible patients were randomly assigned to either the BALANCE Program group (n = 1,266) or the control group (n = 1,268) and were followed up for a median of 3.5 years. In total, 235 (9.3%) participants had been lost to follow-up. After 3 years of follow-up, mean modified Alternative Healthy Eating Index (scale 0-70) was only slightly higher in the BALANCE group versus the control group (26.2 ± 8.4 vs 24.7 ± 8.6, P < .01), mainly due to a 0.5-serving/d greater intake of fruits and of vegetables in the BALANCE group. Primary end point events occurred in 236 participants (18.8%) in the BALANCE group and in 207 participants (16.4%) in the control group (hazard ratio, 1.15; 95% CI 0.95-1.38; P = .15). Secondary end points did not differ between groups after follow-up.

CONCLUSIONS

The BALANCE Program only slightly improved adherence to a healthy diet in patients with established CVD and had no significant effect on the incidence of cardiovascular events or death.

Differential effects of saturated and unsaturated fatty acids on vascular reactivity in isolated mesenteric and femoral arteries of rats

Free fatty acid (FFA) intake regulates blood pressure and vascular reactivity but its direct effect on contractility of systemic arteries is not well understood. We investigated the effects of saturated fatty acid (SFA, palmitic acid), polyunsaturated fatty acid (PUFA, linoleic acid), and monounsaturated fatty acid (MUFA, oleic acid) on the contractility of isolated mesenteric (MA) and deep femoral arteries (DFA) of Sprague-Dawley rats. Isolated MA and DFA were mounted on a dual wire myograph and phenylephrine (PhE, 1-10 µM) concentration-dependent contraction was obtained with or without FFAs. Incubation with 100 µM of palmitic acid significantly increased PhE-induced contraction in both arteries. In MA, treatment with 100 µM of linoleic acid decreased 1 µM PhE-induced contraction while increasing the response to higher PhE concentrations. In DFA, linoleic acid slightly decreased PhE-induced contraction while 200 µM oleic acid significantly decreased it. In MA, oleic acid reduced contraction at low PhE concentration (1 and 2 µM) while increasing it at 10 µM PhE. Perplexingly, depolarization by 40 mM KCl-induced contraction of MA was commonly enhanced by the three fatty acids. The 40 mM KCl-contraction of DFA was also augmented by linoleic and oleic acids while not affected by palmitic acid. SFA persistently increased alpha-adrenergic contraction of systemic arteries whereas PUFA and MUFA attenuated PhE-induced contraction of skeletal arteries. PUFA and MUFA concentration-dependent dual effects on MA suggest differential mechanisms depending on the types of arteries. Further studies are needed to elucidate underlying mechanisms of the various effects of FFA on systemic arteries.

[Non-pharmaceutical treatment of dyslipidemia: review of current methods of diet and nutraceuticals]

The role of nutrition in the development and progression of atherosclerosis is well known. The correction of diet in patients with dyslipidemia is important as an independent intervention (in the group of patients with low and, partially, moderate cardiovascular risk), and as an addition to drug therapy in patients with at higher risk of cardiovascular events. The current review describes the effect of modern methods of diet therapy, as well as the use of a number of nutraceutical agents in terms of evidence-based medicine.

Consumption and Sources of Saturated Fatty Acids According to the 2019 Canada Food Guide: Data from the 2015 Canadian Community Health Survey

The 2019 revised version of Canada’s Food Guide (CFG) recommends limiting the consumption of processed foods that are high in saturated fatty acids (SFA). Yet, the contributions of each CFG group to the total SFA intake of Canadians are not specifically known. The objectives of this study were to quantify the total SFA intake of Canadians, determine the sources of SFA consumed by Canadian adults, and identify potential differences in these sources. A nation representative sample from the Canadian Community Health Survey (CCHS – Nutrition 2015) was used for these analyses. Dietary intakes were measured using a single 24-h recall. Food sources of SFA were classified according to the revised 2019 CFG categories. We have also examined the contribution of foods not included in these three categories to total SFA intake. Among Canadian adults, total SFA contributed to 10.4 ± 0.1% (SE) of total energy intake (E). The “Protein foods” (47.7 ± 0.5% with 23.2 ± 0.4% from milk and alternatives and 24.5 ± 0.4% from meats and alternatives) and “All other foods” (44.2 ± 0.5%) categories were the main sources of total SFA intake. Few differences in SFA sources were identified between sexes, age groups, education levels, and body mass index (BMI) categories. These data show that the mean SFA consumption is greater than the 10% E cut-off previously proposed in Canada. Future studies should examine which food substitution is most likely to contribute to a greater reduction in SFA intake at the population level.

Consumption of Milk and Alternatives and Their Contribution to Nutrient Intakes among Canadian Adults: Evidence from the 2015 Canadian Community Health Survey-Nutrition

As a staple food and dense source of nutrients, milk and alternatives play an important role in nutrient adequacy. The aims of this study were to quantify the consumption of milk and alternatives within Canadian self-selected diets and determine their contribution to intakes of nutrients and energy. First, 24-h dietary recalls from the 2015 Canadian Community Health Survey—Nutrition were used to assess 1-d food and nutrient intakes among Canadian adults ≥19 y (n = 13,616). Foods were classified as milk and alternatives according to the 2007 Canada’s Food Guide. Descriptive statistics were used to calculate daily servings of milk and alternatives by different age groups and demographic characteristics. Population ratios were used to discern their contribution to total intakes of nutrients and energy. Mean daily servings (±SE) were highest for milk (0.60 ± 0.02) and cheese (0.42 ± 0.01), intermediate for frozen dairy (0.16 ± 0.01) and yoghurt (0.14 ± 0.01), and lowest for soy and other dairy (<0.03). Intakes were lowest among Canadians 51 + y (1.3 ± 0.03), females (1.25 ± 0.03), non-Caucasians (1.06 ± 0.05), those with less than a secondary education (1.19 ± 0.05), and British Columbians (1.17 ± 0.05). Milk and alternatives contributed >20% to total intakes of calcium (52.62 ± 0.46%), vitamin D (38.53 ± 0.78%), saturated fat (28.84 ± 0.51%), vitamin B12 (27.73 ± 0.57%), vitamin A (26.16 ± 0.58%), phosphorus (24.76 ± 0.35%), and riboflavin (24.43 ± 0.37%), of which milk was the top source. Milk and alternatives contribute substantially to nutrient intakes and thus warrant further attention in terms of mitigating nutrient inadequacy among the Canadian population.

Pre-Conception Maternal Food Intake and the Association with Childhood Allergies

BACKGROUND

Periconceptional nutrition may have an important function in programming the immune function and allergies, however, there is a lack of studies assessing pre-conception food intake and childhood allergic disorders. The aim of the current study was to identify maternal pre-conception dietary components that may be associated with allergic disorders in children up to 3 years of age.

METHODS

Pregnant women attending their first antenatal visit and who were aged >18 years were invited to participate. Pre-conception food frequency data was retrospectively collected at 18 weeks' gestation. Childhood eczema, current wheeze, and rhinitis was assessed at 36 months of age using a questionnaire and doctor diagnosis (n = 234). Linear discriminant analysis (LDA) was used to explore the combination of dietary food components that best discriminated between allergy status in children.

RESULTS

Maternal pre-conception food intake such as low and high fat dairy, fresh fruit, unsaturated spreads, and take-away foods, were protective for any allergy assessed. Non-oily fish was protective for eczema and current wheeze; saturated spreads (e.g., butter) was protective for eczema, current wheeze, and rhinitis; poultry and fruit juice were adversely associated with each allergy.

CONCLUSIONS

Pre-conception food intakes demonstrate inconsistent and somewhat contrary relationships to the development of child allergies. Whether and how maternal food intake impacts the underlying fetal programming and the mechanisms of childhood allergy warrants further investigation.

Effects of Nutritional Supplements and Dietary Interventions on Cardiovascular Outcomes: An Umbrella Review and Evidence Map

BACKGROUND

The role of nutritional supplements and dietary interventions in preventing mortality and cardiovascular disease (CVD) outcomes is unclear.

PURPOSE

To examine evidence about the effects of nutritional supplements and dietary interventions on mortality and cardiovascular outcomes in adults.

DATA SOURCES

PubMed, CINAHL, and the Cochrane Library from inception until March 2019; ClinicalTrials.gov (10 March 2019); journal Web sites; and reference lists.

STUDY SELECTION

English-language, randomized controlled trials (RCTs) and meta-analyses of RCTs that assessed the effects of nutritional supplements or dietary interventions on all-cause mortality or cardiovascular outcomes, such as death, myocardial infarction, stroke, and coronary heart disease.

DATA EXTRACTION

Two independent investigators abstracted data, assessed the quality of evidence, and rated the certainty of evidence.

DATA SYNTHESIS

Nine systematic reviews and 4 new RCTs were selected that encompassed a total of 277 trials, 24 interventions, and 992 129 participants. A total of 105 meta-analyses were generated. There was moderate-certainty evidence that reduced salt intake decreased the risk for all-cause mortality in normotensive participants (risk ratio [RR], 0.90 [95% CI, 0.85 to 0.95]) and cardiovascular mortality in hypertensive participants (RR, 0.67 [CI, 0.46 to 0.99]). Low-certainty evidence showed that omega-3 long-chain polyunsaturated fatty acid (LC-PUFA) was associated with reduced risk for myocardial infarction (RR, 0.92 [CI, 0.85 to 0.99]) and coronary heart disease (RR, 0.93 [CI, 0.89 to 0.98]). Folic acid was associated with lower risk for stroke (RR, 0.80 [CI, 0.67 to 0.96]; low certainty), whereas calcium plus vitamin D increased the risk for stroke (RR, 1.17 [CI, 1.05 to 1.30]; moderate certainty). Other nutritional supplements, such as vitamin B6, vitamin A, multivitamins, antioxidants, and iron and dietary interventions, such as reduced fat intake, had no significant effect on mortality or cardiovascular disease outcomes (very low- to moderate-certainty evidence).

LIMITATIONS

Suboptimal quality and certainty of evidence.

CONCLUSION

Reduced salt intake, omega-3 LC-PUFA use, and folate supplementation could reduce risk for some cardiovascular outcomes in adults. Combined calcium plus vitamin D might increase risk for stroke.

PRIMARY FUNDING SOURCE

None.

Saturated Fat: Part of a Healthy Diet

PURPOSE OF REVIEW

Despite the American public following recommendations to decrease absolute dietary fat intake and specifically decrease saturated fat intake, we have seen a dramatic rise over the past 40 years in the rates of non-communicable diseases associated with obesity and overweight, namely cardiovascular disease. The development of the diet-heart hypothesis in the mid twentieth century led to faulty but long-held beliefs that dietary intake of saturated fat led to heart disease. Saturated fat can lead to increased LDL cholesterol levels, and elevated plasma cholesterol levels have been shown to be a risk factor for cardiovascular disease; however, the correlative nature of their association does not assign causation.

RECENT FINDINGS

Advances in understanding the role of various lipoprotein particles and their atherogenic risk have been helpful for understanding how different dietary components may impact CVD risk. Numerous meta-analyses and systematic reviews of both the historical and current literature reveals that the diet-heart hypothesis was not, and still is not, supported by the evidence. There appears to be no consistent benefit to all-cause or CVD mortality from the reduction of dietary saturated fat. Further, saturated fat has been shown in some cases to have an inverse relationship with obesity-related type 2 diabetes. Rather than focus on a single nutrient, the overall diet quality and elimination of processed foods, including simple carbohydrates, would likely do more to improve CVD and overall health. It is in the best interest of the American public to clarify dietary guidelines to recognize that dietary saturated fat is not the villain we once thought it was.

Effectiveness of Changes in Diet Composition on Reducing the Incidence of Cardiovascular Disease

PURPOSE OF REVIEW

To highlight dietary changes shown to be associated with a lower risk of cardiovascular events in epidemiological studies and that have been proven to be effective in preventing cardiovascular diseases in clinical trials RECENT FINDINGS: Since dietary changes always involve multiple variables, recent observational and intervention studies on dietary prevention of cardiovascular disease focus not only to the limitation of a single nutrient/food intake but also to the other dietary changes implemented to replace it. The available evidence supports three major dietary strategies for cardiovascular disease prevention: (1) the replacement of saturated fat with unsaturated fat and/or fiber-rich carbohydrate foods; (2) the reduction of salt intake; (3) the implementation of dietary patterns resembling the traditional Mediterranean diet. This support derives not only from RCTs but also from the combination of large observational cohort studies and relatively short-term randomized trials on cardiovascular risk factors.

Triglyceride-glucose index is associated with symptomatic coronary artery disease in patients in secondary care

BACKGROUND

The triglyceride-glucose index (TyG index) is a tool for insulin resistance evaluation, however, little is known about its association with coronary artery disease (CAD), which is the major cardiovascular death cause, and what factors may be associated with TyG index.

OBJECTIVE

To evaluate the association between the TyG index and the prevalence of CAD phases, as well as cardiovascular risk factors.

METHODS

The baseline data of patients in secondary care in cardiology from Brazilian Cardioprotective Nutritional Program Trial (BALANCE Program Trial) were analyzed. Anthropometric, clinical, socio-demographic and food consumption data were collected by trained professionals. The TyG index was calculated by the formula: Ln (fasting triglycerides (mg/dl) × fasting blood glucose (mg/dl)/2) and regression models were used to evaluate the associations.

RESULTS

We evaluated 2330 patients, which the majority was male (58.1%) and elderly (62.1%). The prevalence of symptomatic CAD was 1.16 times higher in patients classified in the last tertile of the TyG index (9.9 ± 0.5) compared to those in the first tertile (8.3 ± 0.3). Cardiometabolic risk factors were associated with TyG index, with the highlight for higher carbohydrate and lower lipid consumption in relation to recommendations that reduced the chance of being in the last TyG index tertile.

CONCLUSION

The TyG index was positively associated with a higher prevalence of symptomatic CAD, with metabolic and behavioral risk factors, and could be used as a marker for atherosclerosis. Trial registration ClinicalTrials.gov identifier: NCT01620398. Registered 15 June, 2012.

Plant-sourced and animal-sourced monounsaturated fatty acid intakes in relation to mortality: a prospective nationwide cohort study

PURPOSE

Monounsaturated fatty acids (MUFAs) are typical components of various plant-sourced and animal-sourced foods. However, the associations of MUFA consumption from different sources with mortality remain unclear. This study aimed to investigate the relationships between MUFA intakes from plant and animal sources and mortality.

METHODS

A total of 14,305 participants from China Health and Nutrition Survey were prospectively followed up for 14 years. Dietary intake of MUFAs was assessed by 3-day 24-h dietary records in each round. Cox proportional hazards regression models were used to compute hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

A total of 1006 deaths occurred during 199,091 person-years of follow-up. Intake of total MUFAs was not associated with mortality (P-trend = 0.17). The plant-sourced MUFA intake was strongly associated with lower mortality [HR_Q4vsQ1 (95% CI) 0.72 (0.58-0.89); P-trend = 0.008], whereas animal-sourced MUFA intake showed no significant association. Likewise, oleic acid (OA) and palmitoleic acid (PA) intakes from plant sources were also inversely associated with mortality [HR_Q4vsQ1 (95% CI) 0.66 (0.52-0.84) for OA and 0.73 (0.59-0.91) for PA], while animal-sourced OA and PA were not related to mortality. Theoretically replacing saturated fatty acids (SFAs) (5% of total energy) with isocaloric plant-sourced MUFAs was associated with 15% (95% CI 5-25%) lower mortality. In addition, 18% (95% CI 10-26%) lower mortality was observed when theoretically replacing the sum of SFAs and animal-sourced MUFAs with isocaloric plant-sourced MUFAs.

CONCLUSIONS

Intakes of MUFAs, including OA and PA, from plant but not animal sources were associated with lower total mortality. These findings suggested the importance of consuming MUFAs from plant-based foods for overall health.

Effect of 'rice' pattern on high blood pressure by gender and obesity: using the community-based KoGES cohort

OBJECTIVE

The present study aimed to examine the association between dietary pattern and the risk of high blood pressure (BP) and to estimate the attenuated effect by gender and obesity on the association using data from a prospective cohort study in Korea.

DESIGN

Prospective study. Diet was assessed using a validated 103-item FFQ and was input into factor analysis after adjustment for total energy intake.

SETTING

Community-based Korean Genome Epidemiology Study (KoGES) cohort.

PARTICIPANTS

Healthy individuals (n 5151) without high BP at recruitment from the community-based cohort study.

RESULTS

Dietary pattern was not associated with the risk of high BP regardless of the type of covariates, with the exception of the 'rice' pattern. The effect of the 'rice' pattern was observed in both men (Ptrend = 0·013) and women (Ptrend < 0·001), but the statistical significance remained only in women after adjustment for confounders (Ptrend = 0·004). The positive association of the 'rice' pattern with high BP risk was attenuated by obesity. After stratification by gender and obese status, in particular, the harmful effect of the 'rice' pattern was predominantly observed in obese women (Ptrend < 0·001) only.

CONCLUSIONS

This longitudinal study in Korean adults found a positive association of the 'rice' pattern with long-term development of incident high BP, predominantly in women. The association is likely to be attenuated by gender and obese status.

Substituting polyunsaturated fat for saturated fat: A health impact assessment of a fat tax in seven European countries

There is evidence that replacing saturated fat (SFA) with polyunsaturated fat (PUFA) lowers ischemic heart disease (IHD). In order to improve the population’s diet, the World Health Organization has called for the taxation of foods that are high in SFA. We aimed to assess the potential health gains of a European fat tax by applying the SFA intake reduction that has been observed under the Danish fat tax to six other European countries. For each country, we created a fat tax scenario with a decreased SFA intake and a corresponding increase in PUFA. We compared this fat tax scenario to a reference scenario with no change in SFA intake, and to a guideline scenario with a population-wide SFA intake in line with dietary recommendations. We used DYNAMO-HIA to dynamically project the policy-attributable IHD cases of these three scenarios 10 years into the future. A fat tax would reduce prevalent IHD cases by a minimum of 500 and 300 among males and females in Denmark, respectively, up to a maximum of 5,600 and 4,000 among males and females in the UK. Thereby, the prevented IHD cases under a fat tax scenario would correspond to between 11.0% (in females in the Netherlands) and 29.5% (in females in Italy) of the prevented IHD cases under a guideline scenario, which represents the maximum preventable disease burden. Henceforth, our quantification of beneficial health impacts makes the case for the policy debate on fat taxes.

Total and Subtypes of Dietary Fat Intake and Its Association with Components of the Metabolic Syndrome in a Mediterranean Population at High Cardiovascular Risk

Background: The effect of dietary fat intake on the metabolic syndrome (MetS) and in turn on cardiovascular disease (CVD) remains unclear in individuals at high CVD risk. Objective: To assess the association between fat intake and MetS components in an adult Mediterranean population at high CVD risk. Design: Baseline assessment of nutritional adequacy in participants (n = 6560, men and women, 55-75 years old, with overweight/obesity and MetS) in the PREvención con DIeta MEDiterránea (PREDIMED)-Plus randomized trial. Methods: Assessment of fat intake (total fat, monounsatured fatty acids: MUFA, polyunsaturated fatty acids: PUFA, saturated fatty acids: SFA, trans-fatty acids: trans-FA, linoleic acid, α-linolenic acid, and ω-3 FA) using a validated food frequency questionnaire, and diet quality using 17-item Mediterranean dietary questionnaire and fat quality index (FQI). Results: Participants in the highest quintile of total dietary fat intake showed lower intake of energy, carbohydrates, protein and fiber, but higher intake of PUFA, MUFA, SFA, TFA, LA, ALA and ω-3 FA. Differences in MetS components were found according to fat intake. Odds (5th vs. 1st quintile): hyperglycemia: 1.3-1.6 times higher for total fat, MUFA, SFA and ω-3 FA intake; low high-density lipoprotein cholesterol (HDL-c): 1.2 higher for LA; hypertriglyceridemia: 0.7 lower for SFA and ω-3 FA intake. Conclusions: Dietary fats played different role on MetS components of high CVD risk patients. Dietary fat intake was associated with higher risk of hyperglycemia.

Prominent positioning and food swaps are effective interventions to reduce the saturated fat content of the shopping basket in an experimental online supermarket: a randomized controlled trial

BACKGROUND

Interventions to reduce the saturated fat (SFA) content of food purchases may help reduce SFA consumption and lower cardiovascular risk. This factorial RCT aimed to examine the effect of altering the default order of foods and being offered a swap on the SFA content of food selected during an online shopping experiment.

METHODS

UK adults who were the primary grocery shoppers for their household were recruited online and invited to select items in a custom-made experimental online supermarket using a 10-item shopping list. Participants were randomly allocated to one of four groups (i) to see products within a category ranked in ascending order of SFA content, (ii) receive an offer to swap to a product with less SFA, (iii) a combination of both interventions, or (iv) no intervention. The primary outcome was the difference in percentage energy from SFA in the shopping basket between any of the four groups. The outcome assessors and statistician were blinded to intervention allocation.

RESULTS

Between March and July 2018, 1240 participants were evenly randomised and 1088 who completed the task were analysed (88%). Participants were 65% female and aged 38y (SD 12). Compared with no intervention (n = 275) where the percentage energy from SFA was 25.7% (SD 5.6%), altering the order of foods (n = 261) reduced SFA by [mean difference (95%CI)] -5.0% (- 6.3 to - 3.6) and offering swaps (n = 279) by - 2.0% (- 3.3 to - 0.6). The combined intervention (n = 273) was significantly more effective than swaps alone (- 3.4% (- 4.7 to - 2.1)) but not different than altering the order alone (- 0.4% (- 1.8 to 0.9)), p = 0.04 for interaction.

CONCLUSIONS

Altering the default order to show foods in ascending order of SFA and offering a swap with lower SFA reduced percentage energy from SFA in an experimental online supermarket. Environmental-level interventions, such as altering the default order, may be a more promising way to improve food purchasing than individual-level ones, such as offering swaps.

TRIAL REGISTRATION

ISRCTN13729526 https://doi.org/10.1186/ISRCTN13729526 26th February 2018.

Patterns of plant and animal protein intake are strongly associated with cardiovascular mortality: the Adventist Health Study-2 cohort

Background

Current evidence suggests that plant and animal proteins are intimately associated with specific large nutrient clusters that may explain part of their complex relation with cardiovascular health. We aimed at evaluating the association between specific patterns of protein intake with cardiovascular mortality.

Methods

We selected 81 337 men and women from the Adventist Health Study-2. Diet was assessed between 2002 and 2007, by using a validated food frequency questionnaire. Dietary patterns based on the participants' protein consumption were derived by factor analysis. Cox regression analysis was used to estimate multivariate-adjusted hazard ratios (HRs) adjusted for sociodemographic and lifestyle factors and dietary components.

Results

There were 2276 cardiovascular deaths during a mean follow-up time of 9.4 years. The HRs for cardiovascular mortality were 1.61 [98.75% confidence interval (CI), 1.12 2.32; P-trend < 0.001] for the 'Meat' protein factor and 0.60 (98.75% CI, 0.42 0.86; P-trend < 0.001) for the 'Nuts & Seeds' protein factor (highest vs lowest quintile of factor scores). No significant associations were found for the 'Grains', 'Processed Foods' and 'Legumes, Fruits & Vegetables' protein factors. Additional adjustments for the participants' vegetarian dietary pattern and nutrients related to cardiovascular disease outcomes did not change the results.

Conclusions

Associations between the 'Meat' and 'Nuts & Seeds' protein factors and cardiovascular outcomes were strong and could not be ascribed to other associated nutrients considered to be important for cardiovascular health. Healthy diets can be advocated based on protein sources, preferring low contributions of protein from meat and higher intakes of plant protein from nuts and seeds.

Trends in Levels of Lipids and Apolipoprotein B in US Youths Aged 6 to 19 Years, 1999-2016

Importance

Favorable trends occurred in the lipid levels of US youths through 2010, but these trends may be altered by ongoing changes in the food supply, obesity prevalence, and other factors.

Objective

To analyze trends in levels of lipids and apolipoprotein B in US youths during 18 years from 1999 through 2016.

Design, Setting, and Participants

Serial cross-sectional analysis of US population-weighted data for youths aged 6 to 19 years from the National Health and Nutrition Examination Surveys for 1999 through 2016. Linear temporal trends were analyzed using multivariable regression models with regression coefficients (β) reported as change per 1 year.

Exposures

Survey year; examined periods spanned 10 to 18 years based on data availability.

Main Outcomes and Measures

Age- and race/ethnicity-adjusted mean levels of high-density lipoprotein (HDL), non-HDL, and total cholesterol. Among fasting adolescents (aged 12-19 years), mean levels of low-density lipoprotein cholesterol, geometric mean levels of triglycerides, and mean levels of apolipoprotein B. Prevalence of ideal and adverse (vs borderline) levels of lipids and apolipoprotein B per pediatric lipid guidelines.

Results

In total, 26 047 youths were included (weighted mean age, 12.4 years; female, 51%). Among all youths, the adjusted mean total cholesterol level declined from 164 mg/dL (95% CI, 161 to 167 mg/dL) in 1999-2000 to 155 mg/dL (95% CI, 154 to 157 mg/dL) in 2015-2016 (β for linear trend, -0.6 mg/dL [95% CI, -0.7 to -0.4 mg/dL] per year). Adjusted mean HDL cholesterol level increased from 52.5 mg/dL (95% CI, 51.7 to 53.3 mg/dL) in 2007-2008 to 55.0 mg/dL (95% CI, 53.8 to 56.3 mg/dL) in 2015-2016 (β, 0.2 mg/dL [95% CI, 0.1 to 0.4 mg/dL] per year) and non-HDL cholesterol decreased from 108 mg/dL (95% CI, 106 to 110 mg/dL) to 100 mg/dL (95% CI, 99 to 102 mg/dL) during the same years (β, -0.9 mg/dL [95% CI, -1.2 to -0.6 mg/dL] per year). Among fasting adolescents, geometric mean levels of triglycerides declined from 78 mg/dL (95% CI, 74 to 82 mg/dL) in 1999-2000 to 63 mg/dL (95% CI, 58 to 68 mg/dL) in 2013-2014 (log-transformed β, -0.015 [95% CI, -0.020 to -0.010] per year), mean levels of low-density lipoprotein cholesterol declined from 92 mg/dL (95% CI, 89 to 95 mg/dL) to 86 mg/dL (95% CI, 83 to 90 mg/dL) during the same years (β, -0.4 mg/dL [95% CI, -0.7 to -0.2 mg/dL] per year), and mean levels of apolipoprotein B declined from 70 mg/dL (95% CI, 68 to 72 mg/dL) in 2005-2006 to 67 mg/dL (95% CI, 65 to 70 mg/dL) in 2013-2014 (β, -0.4 mg/dL [95% CI, -0.7 to -0.04 mg/dL] per year). Favorable trends were generally also observed in the prevalence of ideal and adverse levels. By the end of the study period, 51.4% (95% CI, 48.5% to 54.2%) of all youths had ideal levels for HDL, non-HDL, and total cholesterol; among adolescents, 46.8% (95% CI, 40.9% to 52.6%) had ideal levels for all lipids and apolipoprotein B, whereas 15.2% (95% CI, 13.1% to 17.3%) of children aged 6 to 11 years and 25.2% (95% CI, 22.2% to 28.2%) of adolescents aged 12 to 19 years had at least 1 adverse level.

Conclusions and Relevance

Between 1999 and 2016, favorable trends were observed in levels of lipids and apolipoprotein B in US youths aged 6 to 19 years.

Primary Care SHOPping intervention for cardiovascular disease prevention (PC-SHOP): protocol for a randomised controlled trial to reduce saturated fat intake

INTRODUCTION

A diet high in saturated fat (SFA) increases the risk of cardiovascular disease (CVD) and intakes in the UK exceed dietary recommendations. The Primary Care Shopping Intervention for Cardiovascular Disease Prevention (PC-SHOP) study aims to test the effect of an intervention for people with raised low-density lipoprotein (LDL) cholesterol involving health professional (HP) advice alone, or in combination with personalised feedback based on nutritional analysis of grocery store loyalty card data, on SFA intake and blood lipids in comparison with no intervention.

METHODS AND ANALYSIS

PC-SHOP is a three-arm parallel randomised controlled trial with an allocation ratio of 1:3:3 ('no intervention': n=16, 'brief support': n=48, 'brief support plus shopping feedback': n=48, respectively). Participants with raised LDL will be recruited from general practitioner (GP) practices for a 3-month intervention period. In brief support, an HP will deliver a behaviourally informed 10 min consultation and provide a written self-help guide to inform and motivate people to reduce their SFA intake. In brief support plus shopping feedback, the participants will receive the same HP-led behavioural support and, based on data from their grocery store loyalty card, personalised feedback on the SFA content of their grocery shopping, identifying high SFA purchases and suggesting swaps to similar but lower SFA items.Measurements for the primary and secondary outcomes will be collected at baseline and at follow-up (3 months). The primary outcome measure will be the between-group difference in the reduction of SFA intake between baseline and follow-up. Secondary outcomes include changes in blood lipids and SFA content of food purchases, with process measures to consider the feasibility and acceptability of the intervention.

ETHICS AND DISSEMINATION

This study has been reviewed and approved by the National Health Service Health Research Authority Research Ethics Committee (Ref: 17/SC/0168). The trial findings will be disseminated to academic and HPs through presentations at meetings and peer-reviewed journals and to the public through the media. If the intervention is effective, the results will be communicated to relevant stakeholders, including policymakers and retailers.

TRIAL REGISTRATION NUMBER

ISRCTN14279335; Pre-results.

Chokeberry Juice Containing Polyphenols Does Not Affect Cholesterol or Blood Pressure but Modifies the Composition of Plasma Phospholipids Fatty Acids in Individuals at Cardiovascular Risk

Chokeberry polyphenols have been suggested to reduce cholesterol and blood pressure and thus protect against cardiovascular diseases (CVD), but the evidence in humans is limited and inconsistent. This randomized double-blinded three-parallel groups trial investigated the changes in various anthropometric and clinical biomarkers, and in plasma phospholipids fatty acids (PPFA) in volunteers at cardiovascular risk after a four-week intervention with 100 mL/day of (1) chokeberry juice with a high-dose of polyphenols (1177.11 mg gallic acid equivalents, GAE); (2) chokeberry juice with a low-dose of polyphenols (294.28 mg GAE) and; (3) a nutritionally matched polyphenol-free placebo drink. Our results indicate that the intake of chokeberry juice containing either the low or the high dose of polyphenols cannot be linked with a reduction in total- and low-density lipoprotein (LDL)cholesterol or in systolic (SBP) and diastolic (DBP) blood pressure in comparison with the consumption of the placebo drink. However, we found evidence of moderate changes in the PPFA, i.e., increased saturated fatty acids (SFA), mostly palmitic acid, and reduced n-6 polyunsaturated fatty acids (PUFA), principally linoleic acid (LA) with the intake of chokeberry against the placebo. These effects may be associated with the polyphenols but we could not differentiate a clear dose-response effect. Further research is still needed to elucidate the contribution of the polyphenolic fraction to the potential cardiovascular effects of the chokeberry and to build up the evidence of its potential benefit via the modulation of PPFA composition.

Dietary total fat, fatty acids intake, and risk of cardiovascular disease: a dose-response meta-analysis of cohort studies

BACKGROUND

Several epidemiological studies have investigated the association between dietary fat intake and cardiovascular disease. However, dietary recommendations based on systematic review and meta-analysis might be more credible.

METHODS AND RESULTS

Pubmed, Embase and Cochrane library were searched up to July 1st 2018 for cohort studies reporting associations of dietary fat intake and risk of CVDs. By comparing the highest vs. the lowest categories of fat or fatty acids intake, we found that higher dietary trans fatty acids (TFA) intake was associated with increased risk of CVDs [RR:1.14(1.08-1.21)]. However, no association was observed between total fat, monounsaturated fatty acids (MUFA), saturated fatty acids (SFA), and polyunsaturated fatty acids (PUFA), and risk of CVDs. Subgroup analysis found a cardio-protective effect of PUFA in the studies that has been followed up more than 10 years [0.95(0.91-0.99), I2 = 62.4%]. Dose-response analysis suggested that the risk of CVDs increased 16% [1.16 (1.07-1.25), Plinearity = 0.033] for an increment of 2% energy/day of TFA intake.

CONCLUSIONS

This current meta-analysis of cohort studies suggested that total fat, SFA, MUFA, and PUFA intake were not associated with the risk of cardiovascular disease. However, we found that higher TFA intake is associated with greater risk of CVDs in a dose-response fashion. Furthermore, the subgroup analysis found a cardio-protective effect of PUFA in studies followed up for more than 10 years.

Consumo de alimentos y ataque cerebrovascular isquémico agudo. Estudio multicéntrico de casos y controles

Introducción. La dieta es uno de los factores asociados al ataque cerebrovascular (ACV) con un impacto particular sobre las diferentes poblaciones.Objetivo. Evaluar la asociación entre el consumo de alimentos y el ACV isquémico en una muestra de pacientes adultos en Colombia.Materiales y métodos. Estudio de casos (n=357) y controles (n=348) con casos incidentes de ACV isquémico agudo. El consumo de alimentos fue evaluado mediante un cuestionario de frecuencia de consumo. Se calculó el odds ratio (OR) con sus respectivos intervalos de confianza (IC) del 95% mediante modelos de regresión logística.Resultados. Se identificaron 10 alimentos asociados con el ACV isquémico agudo. Según la escala propuesta (número de modelos con asociación significativa), un solo alimento se ubicó en la categoría de evidencia fuerte de asociación (gallina), cuatro en categoría débil (chocolate, harina de trigo, manteca, aguacate) y cinco en la categoría sospechosa (pollo con piel, pollo sin piel, arroz, arracacha, yuca).Conclusiones. El consumo de chocolate de mesa (preparado en leche con una composición de 70% azúcar y 30% cacao), aguacate y pollo sin piel podría sugerir un efecto protector, mientras la alta ingesta de harina de trigo, gallina, manteca, atún en agua, arroz, pollo con piel, arracacha y yuca podría aumentar el riesgo de presentar ACV isquémico agudo.

Health-Associated Nutrition and Exercise Behaviors in Relation to Metabolic Risk Factors Stratified by Body Mass Index

This study aimed to investigate the relationships of nutrition and exercise behaviors on metabolic risk factors (MRF) when body mass index (BMI) was considered. Health-associated nutrition and exercise behaviors were assessed by a questionnaire, anthropometric values, blood pressure and biochemical determinations that were obtained from 4017 workers. The nutrition score was negatively associated with triglycerides in the overweight subgroup and with systolic blood pressure (SBP) in the obese subgroup. The exercise score was negatively associated with triglycerides and waist circumference (WC) and positively associated with SBP and high-density lipoprotein cholesterol (HDL-C) in the ideal weight subgroup as well as being negatively associated with WC and positively associated with HDL-C in the overweight subgroup. Similarly, the exercise score was negatively associated with WC and positively associated with SBP in the obese subgroup. However, no significant association was found between nutrition or exercise behavior and MRF in the underweight subgroup. In conclusion, the relationships of exercise and nutrition behaviors on MRF varied for different levels of BMI. Exercise showed a significant association with lower WC. Moreover, its effect showed a gradient trend in accordance with the levels of BMI. For ameliorating MRF, exercise seemed to have better effects than nutrition behavior, especially in the ideal weight subgroup.

Trends in total fat and fatty acid intakes and chronic health conditions in Korean adults over 2007-2015

Objective

To investigate trends in total fat and fatty acid intakes and chronic health conditions among Korean adults over nine years between 2007 and 2015.

Design

Cross-sectional, observational study using a stratified, multistage probability sampling design at a national level. Intakes of total fat and fatty acids were estimated from 24 h dietary recalls by sex and age groups. Trends of total fat and fatty acid intakes were determined by multiple linear regression after adjusting for covariates. Trends in age-standardized prevalence of obesity, hypercholesterolaemia and hypertriacylglycerolaemia were examined by sex.

Setting

Korea.

Participants

Population data of 47749 healthy adults (aged ≥19 years) derived from the Korea National Health and Nutrition Examination Survey between 2007 and 2015.

Results

Over the survey period, daily intakes of energy and total, saturated, monounsaturated, polyunsaturated, n-3 and n-6 fats (grams and percentage of energy (%E)) increased steadily. In all sex and age groups, significant increases were seen in SFA intake from 9·9 g (4·7 %E) to 12·0 g (5·3 %E) and in MUFA intake from 9·9 g (4·6 %E) to 13·3 g (5·8 %E). The prevalence of hypercholesterolaemia increased from 10·7 to 17·9 % over the same period.

Conclusions

In Korean adults, total fat, SFA and other fatty acids have been increasing along with the prevalence of hypercholesterolaemia. This information can help set adequate macronutrient and fatty acid distribution ranges in developing population-specific preventive strategies against diet-related illness.

Plant-derived polyunsaturated fatty acids and markers of glucose metabolism and insulin resistance: a meta-analysis of randomized controlled feeding trials

The objective of this meta-analysis was to investigate the effects of plant-derived polyunsaturated fatty acids (PUFAs) on glucose metabolism and insulin resistance. Scopus and PubMed databases were searched until January 2018. Eligible studies were randomized controlled feeding trials that investigated the effects of a diet high in plant-derived PUFA as compared with saturated fatty acids (SFA) or carbohydrates and measured markers of glucose metabolism and insulin resistance as outcomes. Data from 13 relevant studies (19 comparisons of plant-derived PUFA with control) were retrieved. Plant-derived PUFA did not significantly affect fasting glucose (-0.01 mmol/L (95 % CI - 0.06 to 0.03 mmol/L)), but lowered fasting insulin by 2.6 pmol/L (-4.9 to -0.2 pmol/L) and homeostatic model assessment-insulin resistance (HOMA-IR) by 0.12 units (-0.23 to - 0.01 units). In dose-response analyses, a 5% increase in energy (En%) from PUFA significantly reduced insulin by 5.8 pmol/L (95% CI -10.2 to -1.3 pmol/L), but not glucose (change -0.07, 95% CI -0.17 to 0.04 mmol/L) and HOMA-IR (change - 0.24, 95% CI -0.56 to 0.07 units). In subgroup analyses, studies with higher PUFA dose (upper tertiles) reduced insulin (-6.7, -10.5 to -2.9 pmol/L) and HOMA-IR (-0.28, -0.45 to -0.12 units), but not glucose (-0.09, 95% CI -0.18 to 0.01 mmol/L), as compared with an isocaloric control. Subgroup analyses showed no differences in effects between SFA and carbohydrates as replacement nutrients (p interaction ≥0.05). Evidence from randomized controlled trials indicated that plant-derived PUFA as an isocaloric replacement for SFA or carbohydrates probably reduces fasting insulin and HOMA-IR in populations without diabetes.

DASH Dietary Pattern and Cardiometabolic Outcomes: An Umbrella Review of Systematic Reviews and Meta-Analyses

BACKGROUND

The Dietary Approaches to Stop Hypertension (DASH) dietary pattern, which emphasizes fruit, vegetables, fat-free/low-fat dairy, whole grains, nuts and legumes, and limits saturated fat, cholesterol, red and processed meats, sweets, added sugars, salt and sugar-sweetened beverages, is widely recommended by international diabetes and heart association guidelines.

OBJECTIVE

To summarize the available evidence for the update of the European Association of the Study of Diabetes (EASD) guidelines, we conducted an umbrella review of existing systematic reviews and meta-analyses using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach of the relation of the DASH dietary pattern with cardiovascular disease and other cardiometabolic outcomes in prospective cohort studies and its effect on blood pressure and other cardiometabolic risk factors in controlled trials in individuals with and without diabetes.

METHODS

MEDLINE and EMBASE were searched through 3 January 2019. We included systematic reviews and meta-analyses assessing the relation of the DASH dietary pattern with cardiometabolic disease outcomes in prospective cohort studies and the effect on cardiometabolic risk factors in randomized and non-randomized controlled trials. Two independent reviewers extracted relevant data and assessed the risk of bias of individual studies. The primary outcome was incident cardiovascular disease (CVD) in the prospective cohort studies and systolic blood pressure in the controlled trials. Secondary outcomes included incident coronary heart disease, stroke, and diabetes in prospective cohort studies and other established cardiometabolic risk factors in controlled trials. If the search did not identify an existing systematic review and meta-analysis on a pre-specified outcome, then we conducted our own systematic review and meta-analysis. The evidence was summarized as risk ratios (RR) for disease incidence outcomes and mean differences (MDs) for risk factor outcomes with 95% confidence intervals (95% CIs). The certainty of the evidence was assessed using GRADE.

RESULTS

We identified three systematic reviews and meta-analyses of 15 unique prospective cohort studies (n = 942,140) and four systematic reviews and meta-analyses of 31 unique controlled trials (n = 4,414) across outcomes. We conducted our own systematic review and meta-analysis of 2 controlled trials (n = 65) for HbA1c. The DASH dietary pattern was associated with decreased incident cardiovascular disease (RR, 0.80 (0.76⁻0.85)), coronary heart disease (0.79 (0.71⁻0.88)), stroke (0.81 (0.72⁻0.92)), and diabetes (0.82 (0.74⁻0.92)) in prospective cohort studies and decreased systolic (MD, -5.2 mmHg (95% CI, -7.0 to -3.4)) and diastolic (-2.60 mmHg (-3.50 to -1.70)) blood pressure, Total-C (-0.20 mmol/L (-0.31 to -0.10)), LDL-C (-0.10 mmol/L (-0.20 to -0.01)), HbA1c (-0.53% (-0.62, -0.43)), fasting blood insulin (-0.15 μU/mL (-0.22 to -0.08)), and body weight (-1.42 kg (-2.03 to -0.82)) in controlled trials. There was no effect on HDL-C, triglycerides, fasting blood glucose, HOMA-IR, or CRP. The certainty of the evidence was moderate for SBP and low for CVD incidence and ranged from very low to moderate for the secondary outcomes.

CONCLUSIONS

Current evidence allows for the conclusion that the DASH dietary pattern is associated with decreased incidence of cardiovascular disease and improves blood pressure with evidence of other cardiometabolic advantages in people with and without diabetes. More research is needed to improve the certainty of the estimates.

Dietary Fiber Is Independently Related to Blood Triglycerides Among Adults with Overweight and Obesity

BACKGROUND

Metabolic syndrome (MetS), a cluster of visceral adiposity-related risk factors, affects approximately 35% of the United States population. Although improvement in diet quality is an important approach to reducing MetS risk, the role of particular dietary components remains unclear, especially among younger adults. Individual dietary components have been implicated in ameliorating or exacerbating MetS risk; however, the extent to which these factors contribute to MetS prevention has received little attention.

OBJECTIVE

This cross-sectional study aimed to assess relations between diet and individual MetS components in young to middle-aged adults who are overweight and/or obese.

METHODS

Participants aged 25-45 y (N = 117) with overweight and obesity, but no other diagnosed metabolic disease, recorded dietary intake over 7 d. MetS components (waist circumference, blood pressure, glucose, triglycerides [TGs], and high-density lipoprotein cholesterol [HDL]) were measured. Visceral adipose tissue was measured by dual-energy X-ray absorptiometry. Linear regression was used to assess relations between diet and MetS risk factors, adjusting for age, sex, and visceral adipose tissue.

RESULTS

MetS prevalence in this sample was 32%. Energy-adjusted total fiber intake (β = -0.21, P = 0.02) was inversely associated with TG concentrations. No significant relations were observed between other dietary factors and MetS components. These findings indicate that among MetS components, TG concentrations are potentially sensitive to fiber consumption.

CONCLUSIONS

These results provide cross-sectional evidence supporting the protective influence of dietary fiber on MetS components among young to middle-aged adults. Additional, well-designed clinical trials are needed to assess the causal relations between various types of dietary fiber and metabolic disease.

General health checks in adults for reducing morbidity and mortality from disease

BACKGROUND

General health checks are common elements of health care in some countries. They aim to detect disease and risk factors for disease with the purpose of reducing morbidity and mortality. Most of the commonly used individual screening tests offered in general health checks have been incompletely studied. Also, screening leads to increased use of diagnostic and therapeutic interventions, which can be harmful as well as beneficial. It is therefore important to assess whether general health checks do more good than harm. This is the first update of the review published in 2012.

OBJECTIVES

To quantify the benefits and harms of general health checks.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, two other databases and two trials registers on 31 January 2018. Two review authors independently screened titles and abstracts, assessed papers for eligibility and read reference lists. One review author used citation tracking (Web of Knowledge) and asked trial authors about additional studies.

SELECTION CRITERIA

We included randomised trials comparing health checks with no health checks in adults unselected for disease or risk factors. We did not include geriatric trials. We defined health checks as screening for more than one disease or risk factor in more than one organ system.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the risk of bias in the trials. We contacted trial authors for additional outcomes or trial details when necessary. When possible, we analysed the results with a random-effects model meta-analysis; otherwise, we did a narrative synthesis.

MAIN RESULTS

We included 17 trials, 15 of which reported outcome data (251,891 participants). Risk of bias was generally low for our primary outcomes. Health checks have little or no effect on total mortality (risk ratio (RR) 1.00, 95% confidence interval (CI) 0.97 to 1.03; 11 trials; 233,298 participants and 21,535 deaths; high-certainty evidence, I² = 0%), or cancer mortality (RR 1.01, 95% CI 0.92 to 1.12; 8 trials; 139,290 participants and 3663 deaths; high-certainty evidence, I² = 33%), and probably have little or no effect on cardiovascular mortality (RR 1.05, 95% CI 0.94 to 1.16; 9 trials; 170,227 participants and 6237 deaths; moderate-certainty evidence; I² = 65%). Health checks have little or no effect on fatal and non-fatal ischaemic heart disease (RR 0.98, 95% CI 0.94 to 1.03; 4 trials; 164,881 persons, 10,325 events; high-certainty evidence; I² = 11%), and probably have little or no effect on fatal and non-fatal stroke (RR 1.05 95% CI 0.95 to 1.17; 3 trials; 107,421 persons, 4543 events; moderate-certainty evidence, I² = 53%).

AUTHORS' CONCLUSIONS

General health checks are unlikely to be beneficial.

Contrasting Effects of Short-Term Mediterranean and Vegan Diets on Microvascular Function and Cholesterol in Younger Adults: A Comparative Pilot Study

The Mediterranean diet has been shown to improve cardiovascular health. Vegan diets have demonstrated similar benefits, albeit in fewer studies. In a comparative pilot study, we compared the effects of a short-term Mediterranean Diet (MD) and Vegan Diet (VD) on microvascular function and cholesterol levels in a healthy population. Twenty-four young (aged 18 to 35 years) healthy volunteers followed a four-week intervention (MD = 12; VD = 12) ad libitum. Pre and post-intervention anthropometrics, microvascular function (assessed via LDF and expressed as raw CVC and %CVC MAX), dietary-analysis data (Calories, Protein, Carbohydrates, Total Fat, Saturated Fat, Fibre), Mean Arterial Pressure (MAP), Blood Pressure, Total Cholesterol (TC), High Density Lipoprotein (HDL-C) and TC:HDL-C were compared. MD participants reduced Total Fat intake (p = 0.05). Saturated Fat decreased (MD: p = < 0.001; VD: p = 0.004) and Fibre increased (MD: p = 0.02; VD: p = < 0.001) in both groups. Dietary changes reflected improvements in plateau raw CVC in the MD group (p = 0.005), and a reduction in TC (p = 0.045) and weight loss (p = 0.047) in the VD group. The MD led to improvements in microvascular function; the VD led to reduced TC and weight loss. Although both diets might offer CVD risk-reduction benefits, evidence for the MD appeared to be stronger due to changes in vasodilatory ability and NO bioavailability.

Omega-3 fatty acids for the primary and secondary prevention of cardiovascular disease

BACKGROUND

Researchers have suggested that omega-3 polyunsaturated fatty acids from oily fish (long-chain omega-3 (LCn3), including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)), as well as from plants (alpha-linolenic acid (ALA)) benefit cardiovascular health. Guidelines recommend increasing omega-3-rich foods, and sometimes supplementation, but recent trials have not confirmed this.

OBJECTIVES

To assess effects of increased intake of fish- and plant-based omega-3 for all-cause mortality, cardiovascular (CVD) events, adiposity and lipids.

SEARCH METHODS

We searched CENTRAL, MEDLINE and Embase to April 2017, plus ClinicalTrials.gov and World Health Organization International Clinical Trials Registry to September 2016, with no language restrictions. We handsearched systematic review references and bibliographies and contacted authors.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that lasted at least 12 months and compared supplementation and/or advice to increase LCn3 or ALA intake versus usual or lower intake.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion, extracted data and assessed validity. We performed separate random-effects meta-analysis for ALA and LCn3 interventions, and assessed dose-response relationships through meta-regression.

MAIN RESULTS

We included 79 RCTs (112,059 participants) in this review update and found that 25 were at low summary risk of bias. Trials were of 12 to 72 months' duration and included adults at varying cardiovascular risk, mainly in high-income countries. Most studies assessed LCn3 supplementation with capsules, but some used LCn3- or ALA-rich or enriched foods or dietary advice compared to placebo or usual diet. LCn3 doses ranged from 0.5g/d LCn3 to > 5 g/d (16 RCTs gave at least 3g/d LCn3).Meta-analysis and sensitivity analyses suggested little or no effect of increasing LCn3 on all-cause mortality (RR 0.98, 95% CI 0.90 to 1.03, 92,653 participants; 8189 deaths in 39 trials, high-quality evidence), cardiovascular mortality (RR 0.95, 95% CI 0.87 to 1.03, 67,772 participants; 4544 CVD deaths in 25 RCTs), cardiovascular events (RR 0.99, 95% CI 0.94 to 1.04, 90,378 participants; 14,737 people experienced events in 38 trials, high-quality evidence), coronary heart disease (CHD) mortality (RR 0.93, 95% CI 0.79 to 1.09, 73,491 participants; 1596 CHD deaths in 21 RCTs), stroke (RR 1.06, 95% CI 0.96 to 1.16, 89,358 participants; 1822 strokes in 28 trials) or arrhythmia (RR 0.97, 95% CI 0.90 to 1.05, 53,796 participants; 3788 people experienced arrhythmia in 28 RCTs). There was a suggestion that LCn3 reduced CHD events (RR 0.93, 95% CI 0.88 to 0.97, 84,301 participants; 5469 people experienced CHD events in 28 RCTs); however, this was not maintained in sensitivity analyses - LCn3 probably makes little or no difference to CHD event risk. All evidence was of moderate GRADE quality, except as noted.Increasing ALA intake probably makes little or no difference to all-cause mortality (RR 1.01, 95% CI 0.84 to 1.20, 19,327 participants; 459 deaths, 5 RCTs),cardiovascular mortality (RR 0.96, 95% CI 0.74 to 1.25, 18,619 participants; 219 cardiovascular deaths, 4 RCTs), and CHD mortality (1.1% to 1.0%, RR 0.95, 95% CI 0.72 to 1.26, 18,353 participants; 193 CHD deaths, 3 RCTs) and ALA may make little or no difference to CHD events (RR 1.00, 95% CI 0.80 to 1.22, 19,061 participants, 397 CHD events, 4 RCTs, low-quality evidence). However, increased ALA may slightly reduce risk of cardiovascular events (from 4.8% to 4.7%, RR 0.95, 95% CI 0.83 to 1.07, 19,327 participants; 884 CVD events, 5 RCTs, low-quality evidence with greater effects in trials at low summary risk of bias), and probably reduces risk of arrhythmia (3.3% to 2.6%, RR 0.79, 95% CI 0.57 to 1.10, 4,837 participants; 141 events, 1 RCT). Effects on stroke are unclear.Sensitivity analysis retaining only trials at low summary risk of bias moved effect sizes towards the null (RR 1.0) for all LCn3 primary outcomes except arrhythmias, but for most ALA outcomes, effect sizes moved to suggest protection. LCn3 funnel plots suggested that adding in missing studies/results would move effect sizes towards null for most primary outcomes. There were no dose or duration effects in subgrouping or meta-regression.There was no evidence that increasing LCn3 or ALA altered serious adverse events, adiposity or lipids, except LCn3 reduced triglycerides by ˜15% in a dose-dependant way (high-quality evidence).

AUTHORS' CONCLUSIONS

This is the most extensive systematic assessment of effects of omega-3 fats on cardiovascular health to date. Moderate- and high-quality evidence suggests that increasing EPA and DHA has little or no effect on mortality or cardiovascular health (evidence mainly from supplement trials). Previous suggestions of benefits from EPA and DHA supplements appear to spring from trials with higher risk of bias. Low-quality evidence suggests ALA may slightly reduce CVD event and arrhythmia risk.

Omega-6 fats for the primary and secondary prevention of cardiovascular disease

BACKGROUND

Omega-6 fats are polyunsaturated fats vital for many physiological functions, but their effect on cardiovascular disease (CVD) risk is debated.

OBJECTIVES

To assess effects of increasing omega-6 fats (linoleic acid (LA), gamma-linolenic acid (GLA), dihomo-gamma-linolenic acid (DGLA) and arachidonic acid (AA)) on CVD and all-cause mortality.

SEARCH METHODS

We searched CENTRAL, MEDLINE and Embase to May 2017 and clinicaltrials.gov and the World Health Organization International Clinical Trials Registry Platform to September 2016, without language restrictions. We checked trials included in relevant systematic reviews.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing higher versus lower omega-6 fat intake in adults with or without CVD, assessing effects over at least 12 months. We included full texts, abstracts, trials registry entries and unpublished studies. Outcomes were all-cause mortality, CVD mortality, CVD events, risk factors (blood lipids, adiposity, blood pressure), and potential adverse events. We excluded trials where we could not separate omega-6 fat effects from those of other dietary, lifestyle or medication interventions.

DATA COLLECTION AND ANALYSIS

Two authors independently screened titles/abstracts, assessed trials for inclusion, extracted data, and assessed risk of bias of included trials. We wrote to authors of included studies. Meta-analyses used random-effects analysis, while sensitivity analyses used fixed-effects and limited analyses to trials at low summary risk of bias. We assessed GRADE quality of evidence for 'Summary of findings' tables.

MAIN RESULTS

We included 19 RCTs in 6461 participants who were followed for one to eight years. Seven trials assessed the effects of supplemental GLA and 12 of LA, none DGLA or AA; the omega-6 fats usually displaced dietary saturated or monounsaturated fats. We assessed three RCTs as being at low summary risk of bias.Primary outcomes: we found low-quality evidence that increased intake of omega-6 fats may make little or no difference to all-cause mortality (risk ratio (RR) 1.00, 95% confidence interval (CI) 0.88 to 1.12, 740 deaths, 4506 randomised, 10 trials) or CVD events (RR 0.97, 95% CI 0.81 to 1.15, 1404 people experienced events of 4962 randomised, 7 trials). We are uncertain whether increasing omega-6 fats affects CVD mortality (RR 1.09, 95% CI 0.76 to 1.55, 472 deaths, 4019 randomised, 7 trials), coronary heart disease events (RR 0.88, 95% CI 0.66 to 1.17, 1059 people with events of 3997 randomised, 7 trials), major adverse cardiac and cerebrovascular events (RR 0.84, 95% CI 0.59 to 1.20, 817 events, 2879 participants, 2 trials) or stroke (RR 1.36, 95% CI 0.45 to 4.11, 54 events, 3730 participants, 4 trials), as we assessed the evidence as being of very low quality. We found no evidence of dose-response or duration effects for any primary outcome, but there was a suggestion of greater protection in participants with lower baseline omega-6 intake across outcomes.Additional key outcomes: we found increased intake of omega-6 fats may reduce myocardial infarction (MI) risk (RR 0.88, 95% CI 0.76 to 1.02, 609 events, 4606 participants, 7 trials, low-quality evidence). High-quality evidence suggests increasing omega-6 fats reduces total serum cholesterol a little in the long term (mean difference (MD) -0.33 mmol/L, 95% CI -0.50 to -0.16, I² = 81%; heterogeneity partially explained by dose, 4280 participants, 10 trials). Increasing omega-6 fats probably has little or no effect on adiposity (body mass index (BMI) MD -0.20 kg/m², 95% CI -0.56 to 0.16, 371 participants, 1 trial, moderate-quality evidence). It may make little or no difference to serum triglycerides (MD -0.01 mmol/L, 95% CI -0.23 to 0.21, 834 participants, 5 trials), HDL (MD -0.01 mmol/L, 95% CI -0.03 to 0.02, 1995 participants, 4 trials) or low-density lipoprotein (MD -0.04 mmol/L, 95% CI -0.21 to 0.14, 244 participants, 2 trials, low-quality evidence).

AUTHORS' CONCLUSIONS

This is the most extensive systematic assessment of effects of omega-6 fats on cardiovascular health, mortality, lipids and adiposity to date, using previously unpublished data. We found no evidence that increasing omega-6 fats reduces cardiovascular outcomes other than MI, where 53 people may need to increase omega-6 fat intake to prevent 1 person from experiencing MI. Although benefits of omega-6 fats remain to be proven, increasing omega-6 fats may be of benefit in people at high risk of MI. Increased omega-6 fats reduce serum total cholesterol but not other blood fat fractions or adiposity.