The favourable effect of a Mediterranean diet in preventing myocardial infarction and cerebral thrombosis, published last February by researchers using the results from the random PREDIMED trials, has now been extended to encompass the prevention of type 2 diabetes.
This group of Spanish online researchers, coordinated by Miguel Ángel Martínez-González, Professor of Preventive Medicine at the University of Navarra, has just published, in Annals of Internal Medicine, a clinical trial of 3,541 men and women between 55 and 80 years with cardiovascular risk, and all initially free of diabetes. The research, in which the Rovira Virgili University of Reus (Catalonia) also notably participated, has shown that a dietetic intervention promoting the following of a Mediterranean diet (rich in virgin olive oil, nuts, vegetables, fruit, fish, red wine and legumes, but restricted in red meats and sugary desserts) obtained a relative reduction of 30 per cent in risk of developing diabetes. This reduction of risks was observed after combining the results of the two groups assigned a Mediterranean diet and comparing them to a control group which had received advice for following a low-fat diet.
Reduction of risk of up to 40%
The participants were randomly assigned three possible diets: a Mediterranean one supplemented with virgin olive oil, a Mediterranean diet supplemented with nuts, and a control diet (with advice for a low-fat diet). The programme of intervention included termly personal interviews with dieticians, apart from group sessions, also every three months. This programme was continued on average for more than 4 years. No hypocalorific diets or physical exercise programmes were used.
The effectiveness was much higher amongst the group receiving extra-virgin olive oil, with a statistically significant reduction in risk of 40%; the group receiving a nuts-based diet obtained a reduction of 18%.
According to Mr. Martínez-González, lead author of the article, “we knew that diabetes could be prevented by acting intensively on lifestyles through weight-loss programmes (reduction of total number of calories ingested) and encouraging physical exercise, but this is the first time that a random trial has demonstrated that it is also possible to prevent it solely by changing the dietetic pattern, without reduction in calories, nor with weight-loss or physical exercise targets. Moreover”, he added, “this is possible amongst elderly persons”.
The results confirm research published previously by another Spanish study, also directed by Professor Martínez-González, using data from the SUN (University of Navarra Study in its Spanish initials) research, an observational cohort of university graduates. Amongst these graduates a stricter following of a Mediterranean diet was strongly associated with a reduction of risk of contracting diabetes.