The Mediterranean diet, its components, and cardiovascular disease

Abstract

One of the best-studied diets for cardiovascular health is the Mediterranean diet. This consists of fish, monounsaturated fats from olive oil, fruits, vegetables, whole grains, legumes/nuts, and moderate alcohol consumption. The Mediterranean diet has been shown to reduce the burden, or even prevent the development, of cardiovascular disease, breast cancer, depression, colorectal cancer, diabetes, obesity, asthma, erectile dysfunction, and cognitive decline. This diet is also known to improve surrogates of cardiovascular disease, such as waist-to-hip ratio, lipids, and markers of inflammation, as well as primary cardiovascular disease outcomes such as death and events in both observational and randomized controlled trial data. These enhancements easily rival those seen with more established tools used to fight cardiovascular disease such as aspirin, beta-blockers, angiotensin-converting enzyme inhibitors, and exercise. However, it is unclear if the Mediterranean diet offers cardiovascular disease benefit from its individual constituents or in aggregate. Furthermore, the potential benefit of the Mediterranean diet or its components is not yet validated by concrete cardiovascular disease endpoints in randomized trials or observational studies. This review will focus on the effects of the whole and parts of the Mediterranean diet with regard to both population-based and experimental data highlighting cardiovascular disease morbidity or mortality and cardiovascular disease surrogates when hard outcomes are not available. Our synthesis will highlight the potential for the Mediterranean diet to act as a key player in cardiovascular disease prevention, and attempt to identify certain aspects of the diet that are particularly beneficial for cardioprotection.

Keywords: Cardiovascular disease; Mediterranean diet.

Figure 1

Estimates of risk ratio reduction based on recent meta-analyses of trials examining medication adherence vs. placebo and lifestyle interventions vs. control. Estimates on the effect of niacin were removed as there are no recent meta-analyses which include recent negative data. Relative risks are reported with logarithmic conversions and standard errors plotted on the Forest plot. Estimates of lifestyle modifications such as the Mediterranean diet as a whole (106), fruits and vegetables (59, 61, 62), smoking cessation (103), moderate alcohol (105), omega-3 fatty acids (110), and improved physical activity (102) have substantial benefits for CVD prevention not seen with commonly used standard medical therapies such as statins (100, 101), renin-angiotensin system blockade (104), Fibrates (107), aspirin (108), beta-blockers (109),

Figure 2

Collective mechanisms proposed to underlie the protective effect of foods against cardiovascular disease. Clearly, no single ingredient or mechanism can account for all the advantages of certain food groups, and it takes a calorically sensible and balanced variety to derive the greatest benefit for patients.