A new meta-analysis has shown that strictly following the Mediterranean diet reduces the risk of dying from cancer and cardiovascular disease as well as the risk of developing Parkinson’s and Alzheimer’s disease. The investigators say that greater adherence can be a relatively simple tool to reduce the risk of premature death in the general population. This meta-analysis shows, in an overall analysis comprising more than 1.5 million healthy subjects and 40 000 fatal and non-fatal events, that greater adherence to a Mediterranean diet is significantly associated with a reduced risk of overall mortality, cardiovascular mortality, cancer incidence and mortality, and incidence of Parkinson’s disease and Alzheimer’s disease.
“To the best of our knowledge, this is the first report that has systematically assessed, through meta-analysis, the possible association between adherence to a Mediterranean diet, mortality, and the occurrence of chronic diseases in the general population. The practical implication is that we are able to talk to our patients and show them that sticking to this diet, improves their overall health and quality of life,” lead investigator Dr Francesco Sofi commented.
Individuals who stuck strictly to a Mediterranean diet had significant improvements in their overall health, including a 9% reduction in all-cause mortality, a 9% reduction in mortality from cardiovascular disease, and 6% reduction in cancer mortality. Although only three trials examined the association between adhering to the diet and the risk of Parkinson’s and Alzheimer’s disease, there was a reduced risk of these diseases when individuals closely followed the Mediterranean diet.
Definition of adherence to Mediterranean diet
Adherence to a Mediterranean diet was defined through scores that estimated the conformity of the dietary pattern of the studied population with the traditional Mediterranean dietary pattern. Specifically, people whose consumption of components considered to be part of a Mediterranean diet (vegetables, fruits, legumes, cereals, fish, and a moderate intake of red wine during meals) was above the median consumption of the population were assigned a value of one, whereas a value of zero was given to those with consumptions below the median. By contrast, people whose consumption of components presumed not to form part of a Mediterranean diet (red and processed meats, dairy products) was above the median consumption of the population had a value of zero assigned, and the others had a value of one.
“The results overall showed that increasing two points on the adherence score results in a significant protective effect in terms of chronic diseases,” said Sofi. “The study supports the guidelines and recommendations of all the current scientific organisations that encourage the Mediterranean diet. It does say more, however, in terms of adherence, meaning it is important to actually stick with the diet.”
In terms of applying the findings to the real world, Sofi said creating an adherence score based on “a theoretically defined Mediterranean diet” could be used as preventive tool for reducing the risk of mortality and morbidity in the general population. However, he added, it is important to define the diet properly.
The full report is available at www.bmj.com/cgi/content/full/337/sep11_2/a1344
Source: Sofi F, Cesari F, Abbate R, et al. Adherence to Mediterranean diet and health status: meta-analysis. BMJ 2008; 337:a1344. DOI: 10.1136/bmj.a1344.