A Mediterranean diet can reduce the risk of a heart attack, stroke, or early death for hundreds of millions of individuals who are more likely to develop cardiovascular disease, a global evaluation of the evidence revealed.

A diet rich in olive oil, almonds, fish, whole grains, and vegetables has been linked to a number of advantages in the past, and it is generally known that it can help healthy people live longer.

However, there hasn't been much research on how it might benefit people who are at higher risk for cardiovascular disease, including the hundreds of millions of people who are physically sedentary, smoke, or drink excessive amounts of alcohol, as well as those who have high blood pressure, type 2 diabetes, obesity, or high cholesterol.

Presently, guidelines suggest different diets for people who are more likely to develop heart disease, but they frequently rely on evidence with a low degree of reliability from non-randomized research. The world's largest study to date, which included 40 randomized controlled trials involving more than 35,000 participants, has now provided strong evidence.

According to the first comparative assessment of seven programs, which was published in the BMJ journal, Mediterranean and low-fat diets lower the risk of death and heart attack in people who have a higher risk of cardiovascular disease.

Researchers from the US, Canada, China, Spain, Colombia, and Brazil examined 40 trials involving 35,548 participants who were tracked for an average of three years over seven diet programs.

The seven diets were: Mediterranean, low fat, very low fat, modified fat, combined low fat and low sodium, Ornish (a vegetarian diet, low in fat and refined sugar), and Pritikin (a plant-based diet, limiting processed food).

Based on data with a moderate degree of certainty, Mediterranean diet programs were more effective than minimal intervention in reducing cardiovascular diseases risk factors such as all-cause mortality, nonfatal heart attacks, and stroke.

With a certain degree of assurance, low-fat programs outperformed basic interventions in preventing both fatal and non-fatal heart attacks.

Based mostly on evidence with low to moderate certainty, the five additional dietary programs generally had little to no benefit when compared with minimum intervention.

The researchers acknowledged that their study had a number of limitations, including the inability to assess diet program adherence and the potential that some of the benefits might have come from other aspects of the programs, such as medication and assistance with quitting smoking. Nonetheless, the BMJ said it was a thorough review.