Barriers to adopting a Mediterranean diet in Northern European adults at high risk of developing cardiovascular disease

Background

Strong evidence links the consumption of a Mediterranean diet (MD) with a reduced cardiovascular disease (CVD) risk; however, there is uncertainty as to whether non‐Mediterranean regions will adopt this diet. The present qualitative research aimed to investigate attitudes towards a MD in individuals at high CVD risk in a Northern European population. This information is needed to inform development of MD interventions in non‐Mediterranean high‐risk populations.

Methods

Focus groups (n = 12) were held with individuals at high CVD risk from Northern Europe (≥2 CVD risk factors, aged ≥50 years, no established CVD/type 2 diabetes). Attitudes to dietary change towards a MD were explored. Data were analysed using inductive thematic analysis.

Results

Sixty‐seven adults participated (60% female, mean age 64 years). There was some awareness of the term MD but limited knowledge of its composition. Barriers to general dietary change were evident, including perception of expense , concern over availability , expectation of time commitment , limited knowledge , lack of cooking skills , amount and conflicting nature of media information on diets , changing established eating habits and resistance to dietary change . Barriers specific to MD adoption were also identified, including perceived difficulty living in a colder climate , perceived impact on body weight , acceptability of a MD and cultural differences .

Conclusions

Knowledge of a MD was limited in this Northern European sample at high CVD risk. In addition to general barriers to dietary change, barriers specific to a MD were identified. These findings have implications for the development of interventions aiming to promote MD adoption in non‐Mediterranean populations.

     

Lack of effect of dietary n-6:n-3 PUFA ratio on plasma lipids and markers of insulin responses in Indian Asians living in the UK

Summary Background Indian Asians living in Western Countries have an over 50 % increased risk of coronary heart disease (CHD) relative to their Caucasians counterparts. The atherogenic lipoprotein phenotype (ALP), which is more prevalent in this ethnic group, may in part explain the increased risk. A low dietary long chain n-3 fatty acid (LC n-3 PUFA) intake and a high dietary n-6 PUFA intake and n-6:n-3 PUFA ratio in Indian Asians have been proposed as contributors to the increased ALP incidence and CHD risk in this subgroup. Aim To examine the impact of dietary n-6:n-3 PUFA ratio on membrane fatty acid composition, blood lipid levels and markers of insulin sensitivity in Indian Asians living in the UK. Methods Twentynine males were assigned to either a moderate or high n-6:n-3 PUFA (9 or 16) diet for 6 weeks. Fasting blood samples were collected at baseline and 6 weeks for analysis of triglycerides, total-, LDL- and HDL-cholesterol, non-esterified fatty acids, glucose, insulin, markers of insulin sensitivity and C-reactive protein. Results Group mean saturated fatty acid, MUFA, n-6 PUFA and n-3 PUFA on the moderate and high n-6:n-3 PUFA diets were 26 g/d, 43 g/d, 15 g/d, 2 g/d and 25 g/d, 25 g/d, 28 g/d, 2 g/d respectively. A significantly lower total membrane n-3 PUFA and a trend towards lower EPA and DHA levels were observed following the high n-6:n-3 PUFA diet. However no significant effect of treatment on plasma lipids was evident. There was a trend towards a loss of insulin sensitivity on the high n-6:n- 3 PUFA diet, with the increase in fasting insulin (P = 0.04) and HOMA IR [(insulin x glucose)/ 22.5] (P = 0.02) reaching significance. Conclusion The results of the current study suggest that, within the context of a western diet, it is unlikely that dietary n-6:n-3 PUFA ratio has any major impact on the levels of LC n-3 PUFA in membrane phospholipids or have any major clinically relevant impact on insulin sensitivity and its associated dyslipidaemia. Source of support: This project was funded by the Food Standards Agency (FSA), UK.     

2-OHOA supplementation reduced adiposity and improved cardiometabolic risk to a greater extent than n-3 PUFA in obese mice

ObjectiveWe aimed to assess whether 2-hydroxyoleic acid (2-OHOA) and n-3 polyunsaturated fatty acids (PUFA) could counteract changes on adipokine secretion and cardiometabolic risk biomarkers associated with high-fat diet-induced obesity in mice.MethodsFemale ICR/CD1 mice (8 weeks old) were divided into four groups receiving different diets (n = 8/group): (1) standard chow (control) for 18 weeks; (2) 22% fat for 4 weeks + 60% fat for 14 weeks (obesogenic diet, OD); 3) OD + 2-OHOA (1500 mg kg^?1 diet) for the last 6 weeks (ODHO); and 4) OD + n-3 PUFA (eicosapentaenoic + docosahexaenoic acids, 1500 + 1500 mg kg^?1 diet) for the last 6 weeks (OD-N3). After 18 weeks, body weight, periovarian visceral fat, heart and liver weights were measured, as well as cardiometabolic parameters (systolic and diastolic blood pressure, blood glucose, insulin, HOMA index, triglycerides, total cholesterol, apolipoproteins A1 and E), plasma adipokines and inflammatory proteins (leptin, adiponectin, plasminogen activator inhibitor 1 [PAI1], soluble E-selectin [sE-selectin], matrix metalloproteinase-9 [MMP-9], fibrinogen, soluble intercellular adhesion molecule [sICAM] and soluble vascular adhesion molecule [sVCAM]), and secretion of pro-inflamatory cytokines and inflammatory biomarkers from periovarian adipocytes.ResultsOD mice had greater body and heart weights, and plasma leptin, and lower adiponectin and resistin secretion from adipocytes. Supplementation with 2-OHOA reduced body and heart weights, blood pressure, triglycerides and leptin, and restored adiponectin and resistin secretion, while n-3 PUFA only reduced triglyceride levels (all P < 0.05).Conclusion2-OHOA supplementation was more effective in reducing adiposity, modulating adipokine secretion and ameliorating cardiometabolic risk than n-3 PUFA.     

Low n-6:n-3 fatty acid ratio,with fish- or flaxseed oil,in a high fat diet improves plasma lipids and beneficially alters tissue fatty acid composition in mice

BACKGROUND: Health benefits from low n-6:n-3 fatty acid (FA) ratio on cardiovascular risk have been shown. However, the impact of the source of n-3 FAs has not been fully investigated. AIM: Our purpose was to investigate cardiovascular benefits of oils with a low ratio of n-6:n-3 FAs, but different sources of n-3 FAs in C57BL/6 mice. METHODS: Twenty-one mice were divided into 3 groups (n=7) and fed a diet supplemented with either a fish or flaxseed oil-based 'designer oils' with an approximate n-6:n-3 FA ratio of 2/1 or with a safflower-oil-based diet with a ratio of 25/1, for 16 weeks. Plasma lipids and fatty acid profile of the liver tissue were characterized. RESULTS: Compared to baseline, plasma triacylglycerol levels declined (>50%) in all groups by week 4. Plasma cholesterol levels were reduced in both fish and flax groups by 27% and 36%, respectively, as compared to controls at endpoint. The levels of EPA and DHA in liver phospholipids were significantly increased in both fish and flax groups as compared to the control group, with more profound increases in the fish group. Arachidonic acid levels were similarly decreased in the liver tissues from both fish and flax groups as compared to controls. CONCLUSIONS: Our data suggest that health benefits may be achieved by lowering dietary n-6:n-3 FA even in a high fat diet medium.