Why the Mediterranean diet allows you to live longer in good health

What is meant by “Mediterranean diet”

This mode of eating, characteristic of populations around the Mediterranean, is based on a few simple principles: a large place given to vegetables, fruits, legumes, fish, whole grains and nuts; L’olive oil as the main fatty substance; a moderate presence of meat, dairy products and red wine. Conversely, ultra-processed products and added sugars occupy a marginal place.

It is less a diet in the restrictive sense of the term than an art of living anchored in a culture: studies on populations who practice it naturally show that its benefits are built over years, even decades. In addition to its effects on the heart, the Mediterranean diet is associated with many other health benefits, including longevity. So can we live longer eating Mediterranean and why?

Read: The Mediterranean diet is good for memory and Alzheimer’s

What Studies Show on the Mediterranean Diet

Two extra years of life

In 2016, Swedish researchers analyzed data from 71,333 people followed from 1998 to 2012. Each participant was assigned a score for adherence to the Mediterranean diet, from 0 to 8. Result: between the people least and most faithful to this dietary pattern, the gap in life expectancy reached 23 monthsor almost two additional years (1).

Live longer and healthier

The Great American Nurses’ Cohort Health Study confirms and clarifies this benefit : women following a Mediterranean diet around the age of 60 would more often reach the age of 70, and with a 40% greater chance of remaining in good health. Not only did they more often exceed the age of 70, but they suffered less from chronic diseases (heart, diabetes) or other physical or mental problems (2). The gain is therefore not only quantitative: it is the quality of the years gained that is at stake.

More recently, a study carried out by researchers from Harvard, Copenhagen and Montreal on 105,000 health professionals followed for 30 years estimated the additional chances of remaining in good health after age 70 at 86% for those adopting a diet rich in plants, whole grains, good fats and legumes — so many pillars of the Mediterranean model (3).

More centenarians in the Mediterranean: the “blue zones”

These figures echo a field observation. Certain regions of the world, which Dan Buettner called “blue zones”, concentrate a high number of healthy centenarians : Sardinia in Italy, Icaria in Greece, Okinawa in Japan, or the Nicoya Peninsula in Costa Rica (4).

Dan Buettner describes the lifestyle choices, dietary and otherwise, that would allow you to live longer.

• In Ikaria, the low prevalence of dementia is linked not only to the Mediterranean diet, but also to the daily consumption of infusions (rosemary, sage, mint) with anti-inflammatory and diuretic properties.
• In Sardinia, meat is reserved for special occasions, and one or two glasses of red wine accompany meals.

But the longevity of these populations cannot be reduced to their food. Gentle, daily physical activity (walking), strong social bonds and the meaning given to existence are equally determining components.

Read: Is there a long-life diet?

Why it works: the mechanisms

Protective effects on DNA

Eating Mediterranean preserves chromosomes. This is what a study suggests Harvard Medical School of Boston (5). In this article, the researchers wanted to know if adherence to a Mediterranean diet was associated with longer telomeres. Telomeres are repeated DNA sequences located at the ends of chromosomes that gradually wear away with each cell division. Telomere length is a marker of aging: shorter telomeres are associated with reduced life expectancy and an increased frequency of age-related chronic diseases.

The researchers used data from the cohort Nurses’Health Study. Results: The higher the adherence to the Mediterranean diet, the longer the telomeres. For one point difference on the adherence scale, the difference in telomere length was equivalent to approximately 1.5 years of life. A 3-point change in this adherence score was equivalent to 4.5 years of aging, a difference comparable to that between smokers and non-smokers.

The explanation lies in the anti-inflammatory and antioxidant properties of the diet: fruits, vegetables, nuts, herbs and red wine moderate oxidative stress and chronic inflammation, two of the main accelerators of telomeric wear.

A rejuvenated intestinal microbiota

More recent research has shed light on another mechanism: the effect of the Mediterranean diet on the intestinal microbiota. A study published in the journal Gut analyzed the intestinal microbiota of 612 people aged 65 to 79 years, before and after they followed a Mediterranean diet specially adapted for older people for 12 months (6). Participants were either “non-frail” or “pre-frail” and lived in 5 European countries (France, Italy, Netherlands, Poland, United Kingdom).

The results show that following a Mediterranean diet for a year stimulates intestinal bacteria linked to “healthy” aging, those found in non-frail seniors, while reducing intestinal bacteria associated with inflammation.

The Mediterranean diet has in fact made it possible to contain the loss of bacterial diversity and to increase the presence of certain bacteria previously associated, on the one hand, with markers of reduced fragility and on the other hand, with an improvement in brain function. Finally, these beneficial intestinal bacteria, whose production is favored by a Mediterranean dietare also associated with a reduction in markers of inflammation. The bacteria present in the microbiota of people who followed the Mediterranean diet promote the production of short-chain fatty acids, which are beneficial for health.

Cardiovascular and cerebral protection

This is the longest documented effect. Olive oil improves lipid profile ; omega-3s from fish reduce inflammation; B group vitamins slow down brain atrophy. Conversely, limiting grilled meat reduces exposure to advanced glycation products, implicated in the risk of dementia. Current evidence suggests that the Mediterranean diet may delay the onset of the first symptoms of Alzheimer’s disease.

In conclusion, the Mediterranean diet works as a whole: it is the overall consistency of the diet, and not the presence of an isolated “superfood”, which explains its effects. And as we see in the blue zones, diet is not everything. It acts in synergy with regular physical activity, quality sleep and strong social connections.

Read also: Evi Siougari: “The Cretan way of life contributes to good health”