Nuts, metabolic syndrome and diabetes

Abstract

The ability of nuts to improve the blood lipid profile and reduce the risk of CHD is now well established. The interest that health effects of nuts have gained recently has brought the possible benefits of consuming nuts, such as improvement in the conditions of the metabolic syndrome, and their potential to prevent and control diabetes into focus. Results from cohort studies have associated nut consumption with a reduced risk of developing diabetes and CVD. However, few randomised controlled trials have assessed the effect of nuts on diabetes control, and those that have been undertaken have shown improvements in blood lipids but not in the glycaemic control. Diabetes agencies are increasingly recognising the importance of controlling postprandial glycaemia fluctuations. Acute feeding studies indicate that nuts have minimal effects on rising postprandial blood glucose levels when eaten alone, and diminish the postprandial glycaemic response when consumed with high-glycaemic index carbohydrate foods in both normoglycaemic and type 2 diabetic individuals. Nuts have a healthy nutritional profile, high in MUFA and PUFA, are a good source of vegetable protein and are rich in fibre, vitamins and minerals. Incorporation of nuts in the diet may therefore improve the overall nutritional quality of the diet. While more research is required to establish the ability of nuts to improve glycaemic control in the long run, early data indicate that the inclusion of nuts in the diets of individuals with diabetes and the metabolic syndrome is warranted, in view of their potential to reduce CHD risk. Nuts: CHD: Diabetes: Metabolic syndromeThe worldwide prevalence of the metabolic syndrome and type 2 diabetes is increasing. Currently, 27 % of adults in the United States and 20 -25 % of adults worldwide suffer from the metabolic syndrome, and evidence suggests that the rates are on the rise (1,2) . Similarly, current estimates predict a further 50 % increase in the worldwide prevalence of type 2 diabetes by the year 2030 (3)

Frequency of nut consumption and mortality risk in the PREDIMED nutrition intervention trial

“…The frequency of nut consumption has been inversely related to several chronic prevalent conditions, such as diabetes, hyperlipidemia, hypertension, obesity, metabolic syndrome, cancer, and CHD, among others [5,26]. These inverse associations can be influenced by various mechanisms: nuts improve the blood lipid profile [6] and appear to decrease insulin resistance [8], and there is also evidence suggesting that they can modulate inflammation [35], oxidative stress [36], and endothelial function [37]. As a large body of evidence supports the beneficial effects of frequent nut consumption on many health outcomes, it is plausible that nuts protect as well against all-cause mortality.…”

“…The frequency of nut consumption was also related to lower rates of sudden cardiac death in a large cohort of men [7]. Furthermore, epidemiologic studies and clinical trials have shown that frequent nut consumption is associated with a reduced load of cardiovascular disease risk factors, such as dyslipidemia, type 2 diabetes, and metabolic syndrome [4,6,8,9]. In addition, reports from the Iowa Women’s Health study [10], a large Dutch cohort [11], and the US Nurses’ Health Study [12], which assessed populations with relatively low overall nut intake, suggested that frequent nut consumption related inversely to total mortality, albeit the protective effect was weak, with adjusted risk reductions ranging from 5% to 15% [10]–[12].…”

Evaluation of the content and bioaccessibility of iron, zinc, calcium and magnesium from groats, rice, leguminous grains and nuts

“…By virtue of their unique composition, nuts are likely to beneficially impact heart health and reduce the incidence of diabetes. Epidemiologic studies have associated nut consumption with a reduced incidence of coronary heart disease in both genders and diabetes in women (Kendall et al 2010;Ros et al 2010). Brazil nuts were found to contain highly variable and often very high concentrations of Se, Ba and Sr (Caglarirmak 2003).…”

Complementary and alternative medicine: Herbals and supplements: A review for the primary care physician

“…Nuts are a worthwhile inclusion in the diet of patients with metabolic syndrome and diabetes, as data provides support for improved glycemic control and decreased cardiovascular risk [102]. Nut consumption four times a week has been demonstrated to decrease risk for coronary artery disease by 37% based on four large prospective studies [103].…”