What about the Mediterranean lifestyle reduces mortality? Scientists find out

by | Sep 26, 2023

Scientists unravel the factors of the Mediterranean lifestyle that lead to reduced mortality and how it can be adopted in non-Mediterranean populations.
Picture of a salad on a pink background.

Picture this: Olive oil, tomato, garlic, and an abundance of fruits — a delightful communal meal followed by a short nap. Throw in some sun and moderate warm temperatures and you might find yourself transported to the idyllic Mediterranean.

But what if I told you that you bring the benefits of the Mediterranean lifestyle home with you, even if you live far from the region? Just like a cherished souvenir brought back from holidays.

“The Mediterranean lifestyle represents a traditional way of living based on a plant-based diet rich in fruits, vegetables, legumes, nuts, whole grains, and healthy oils (e.g., olive oil), moderated intake of fish, dairy and very low in red and processed meats or sweets along with food habits such as adding spices instead of salt,” explained Mercedes Sotos-Prieto, assistant professor at the Department of Preventive Medicine, Public Health and Microbiology at the Universidad Autónoma de Madrid.

“Meals are something that happens around family and friends,” she continued. “The conviviality and social aspect are also characteristic. Physical activity is important in the context of community life, and adequate rest including the typical short mid nap or siesta.”

Sotos-Prieto and researchers from the Universidad Autónoma de Madrid in Spain and the Harvard Chan School of Public Health in the USA are exploring the feasibility and impact of adopting the Mediterranean diet and lifestyle among non-Mediterranean populations using locally available products and within their own cultural contexts.

“We are seeing the transferability of the lifestyle [outside the Mediterranean] and its positive effects on health,” she added. The most significant perk? A 29% lower risk of mortality in both men and women.

Breaking down the effects

Scientists stress that the Mediterranean diet should be understood more as a way of life than a mere dietary pattern with scientific evidence acquired over the last four decades establishing its benefits on life expectancy, quality of life, and the prevention of several chronic diseases.

However, the challenge lies in deciphering which elements of the Mediterranean lifestyle contribute most significantly to improved health. Sotos-Prieto and her team designed and developed a Mediterranean lifestyle index called MEDLIFE using a questionnaire that calculated an individual’s adherence to a Mediterranean way of life. This index considers three primary components: food consumption, dietary habits, and physical activity, including rest, social habits, and conviviality.

This type of analysis allowed the researchers to dissect the impact of each of these components, even drilling down to specific items like “hours of sleep” or “socializing with friends”. Moreover, the MEDLIFE index could help capture synergistic effects of multiple components that may not be apparent when examining individual components in isolation.

In their study, the team evaluated the impact of a Mediterranean-like lifestyle over the course of ten years in more than 110,000 participants located in the UK.

The scientists found that adoption of the Mediterranean lifestyle was indeed feasible and could be adapted to local contexts, such as availability of ingredients, their affordability, local culinary traditions, and food preferences. Participants were found to have lowered their risk of cancer and cardiovascular disease relative to the general population.

“We found that the three blocks of the MEDLIFE were independently associated with lower […] mortality,” explained Sotos-Prieto. “And within block 3 [physical activity, rest, social habits, and conviviality] we found that participating in collective sports, limiting sedentary activities, and having adequate hours of sleep (6-8 hours) were associated with lower mortality.” 

However, there were some variables that could not be taken into account due to a lack of information. This was the case for olive oil consumption, a prominent component of the Mediterranean diet previously associated with protective roles in many chronic diseases. “It is probable that we are underestimating the Mediterranean lifestyle association,” said Sotos-Prieto.

To nap or not to nap?

The siesta, a brief afternoon nap, is a traditional habit in Mediterranean countries. But scientists are undecided as to whether it is a healthy practice.

In the current study, specific napping habits were found to be associated with higher risk of mortality and cardiovascular disease. However, and similar to the case of olive oil consumption, the researchers say they did not have detailed information on frequency and duration of naps or sleep structure, such as how often and for how long, which they say weakens their conclusion.

“Moreover, reverse causation is also possible, with people napping because of subclinical conditions or other chronic diseases (for instance, if they had more prevalence of sleep apnea), especially since napping faces a stigma in Anglo-Saxon countries,” said Sotos-Preito.

”Previous studies have found a J-shaped relationship — a smile-like curve — between napping and cardiovascular diseases,” said Sotos-Prieto. This type of chart illustrates situations in which low values of one variable (in this case, a short nap duration) lead to a decrease in the values of the second variable (incidence of cardiovascular events), while the trend reverses at higher values.

“Short naps, which range from 0 to 30 minutes, were associated with lower incident cardiovascular disease,” said Sotos-Preito. “An inverse association between short naps and mortality and cardiovascular diseases was found in our previous publications.”

When asked for a definitive answer as to whether napping was indeed beneficial or not, Sotos-Prieto indicated that more research is needed in this regard.

Adapting to the lifestyle

The challenge remains in how to put these results into practice in other countries with different, deep-rooted customs. Cultural adaptation of beneficial practices is essential to make the Mediterranean diet and habits more appealing and practical for diverse populations in non-Mediterranean countries. 

“One way to start could be to emphasize the use of fresh, local products and ingredients in Mediterranean-style meals,” said Sotos-Prieto. “[But] changing dietary habits and lifestyle is a gradual process, and affordability is also an important question.” 

Other questions remain as to how governments should invest in introducing new healthy habits, which ones should be given preference, and how much change is it enough to start seeing benefits.

The task is not simple since culture can define anything from ingredients and recipes to different social habits and work-life schedules. But Sotos-Prieto is optimistic.

“I think that picking realistic goals, even if small, and sustaining them over time can make a difference [in public health],” concluded Sotos-Prieto.

Reference: Maroto-Rodriguez J. et al., Association of a Mediterranean Lifestyle With All-Cause and Cause-Specific Mortality: A Prospective Study from the UK Biobank, Mayo Clinic proceedings (2023). DOI: 10.1016/j.mayocp.2023.05.031

Feature image credit: Brooke Lark on Unsplash

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