A study with more than 100,000 people concludes that adhering to diets such as the Mediterranean diet reduces the risk of mortality by between 18% and 24%, regardless of genetic predisposition.

Eating healthily reduces mortality and increases life expectancy, regardless of our genetic profile. This is confirmed by a new study based on the biomedical data of 104,000 people.

The authors of this study, published in the journal Science  Advances , sought to determine whether there was an association between adherence to any of five diets considered healthy and mortality and life expectancy. To do this, they used the UK Biobank, a database containing biological samples, health information, genetic data, and lifestyle data from 500,000 people living in the United Kingdom who agreed to provide their biomedical data for research. The researchers analyzed data collected over 11 years from 104,000 participants in the UK Biobank.

The five diets considered in this study have “a lot of similarities, in that they emphasize the intake of fruits, vegetables, whole grains. And they often assign a negative score to red meat and sugary drinks,” summarizes Anne-Julie Tessier, professor in the Department of Nutrition at the University of Montreal and researcher at the Montreal Heart Institute, who published a very similar study in 2025 in Nature Medicine .

The Dietary Approaches to Stop Hypertension ( DASH ) differs from the other four in that it is much stricter regarding sodium. The Healthy Plant-Based Diet Index ( hPDI), on the other hand, assigns negative points to all animal-based foods (dairy products, eggs, fish, and seafood) and positive points to plant-based foods, with the exception of refined grains, fruit juices, and potatoes. Potatoes are also excluded from the Alternate Healthy Eating Index ( AHEI ) . The Alternate Mediterranean Diet ( AMED ) emphasizes fish consumption and stresses the importance of eating fruits and vegetables.

The diabetes risk reduction diet [ DRRD ] was developed using scientific data with the aim of achieving an optimal diet that can be associated with a reduction in inflammation and insulin resistance, among other things.

The study showed that these five dietary patterns reduced the risk of all-cause mortality by 18% to 24% (depending on participants’ adherence to the diet). Furthermore, they added 2 to 3 years of life to the lifespan of 45-year-old men, and 1.5 to 2.3 years to that of women. The authors also emphasize that these healthy diets extended life expectancy regardless of whether individuals carried longevity genes.

The authors specify that all five diets were associated with a lower risk of chronic diseases — cardiovascular disease, stroke, cancer, type 2 diabetes — which would explain a longer life expectancy for those who adopted one of these diets.

Mortality and diabetes

The results indicate that the diabetes risk-reducing diet (DRRD) had the greatest impact on reducing all-cause mortality. This association was even stronger in individuals carrying genes predisposing them to a shorter life expectancy, as well as in current and former smokers.

According to the authors, this result could be explained by the fiber intake and low glycemic index targeted in the DRRD diet.  

“Dietary fiber, found in fruits, vegetables, and whole grains, helps control blood sugar. Poor blood sugar control is linked to cardiovascular disease, which affects brain health. This explains the link with mortality in general.”

“Another possible explanation is that a diet that is particularly effective at improving insulin sensitivity [such as the DRRD] could have greater potential to prevent chronic diseases and premature deaths, as insulin sensitivity plays a crucial role in the development and progression of chronic diseases,” they argue in their article.

Insulin is the key that allows glucose to enter the cells of our body where it will be used. When a person has developed insulin resistance, their cells respond less effectively to insulin, leading to an accumulation of glucose in the bloodstream, which will have a negative effect on blood vessels, explains Ms. ^Tessier  .

In this regard, the results of their study indicate that a diet with a high glycemic index, that is to say, whose foods cause a rapid and significant increase in blood sugar levels, was associated with an increase in all-cause mortality.

“These dietary patterns emphasize the consumption of vegetables, fruits and whole grains that are rich in fiber, flavonoids and other antioxidants, compounds that help improve metabolic regulation, reduce inflammation and maintain a balanced gut microbiota,” the researchers say.

“The antioxidant potential of these diets could explain the very strong association observed between the DRRD diet and reduced mortality in smokers, given that smoking is known to increase oxidative stress, inflammation and dysregulation of metabolism,” they note.

They also point out that the various diets advise against “sugary drinks which promote insulin resistance, the conversion of carbohydrates into triglycerides by the liver, which disrupt the intestinal microbiota and, as a result, hinder general metabolism.”