Why one particular diet is found to be the best year after year

Over years of research and diet rankings, one regimen has consistently been found to bring a host of health benefits, and it hasn’t fallen out of favor amid changing fads.

The Mediterranean diet once again topped the list in U.S. News & World Reports’ annual ranking for 2024 — for the seventh consecutive time — earning it a renewed wave of media attention.

The eating regimen is plant-based and emphasizes multiple servings of fruits and vegetables daily, alongside whole grains, legumes, nuts, olive oil and seafood.

Red meats are eaten only occasionally, and dairy and poultry are consumed in moderation, as well. Highly processed foods or those with added sugars are generally avoided.

Researchers and dietitians say following the diet long term can increase the odds of living a longer, healthier life. A wealth of studies suggest it lowers risk of heart disease and Type 2 diabetes, while potentially slowing cognitive decline.

“It’s a way of life, it’s a cuisine, it dates back thousands of years, and in the last five to six decades, it is the most highly researched cuisine in the world,” said Dr. Catherine Itsiopoulos, a professor of nutrition and dietetics at RMIT University in Melbourne, Australia, who has published several books on the Mediterranean diet.

Here’s what sets the Mediterranean diet apart.

The diet reduces the risk of heart disease

The bulk of evidence centers on the Mediterranean diet’s link to a lower risk of cardiovascular disease and related conditions like obesity, high cholesterol and hypertension.

According to a 2021 review of research, the diet has been shown to reduce the risk of coronary heart disease in women by 29% and stroke by 13%. A 2017 analysis, meanwhile, found that it can lower the risk of coronary heart disease, heart attacks and strokes by 40%, on average.

That may be because the fats in olive oil, seeds, fish and nuts are the healthy kind: monounsaturated or polyunsaturated fats. By contrast, red meat, cheese, dairy and highly processed foods like cookies or chips are packed with unhealthy fats that can clog arteries with plaque.

Those fatty foods can also cause chronic, low-grade inflammation, which occurs when certain types of immune system cells remain present too long, according to Dr. Selvi Rajagopal, an assistant professor of medicine at the Johns Hopkins University School of Medicine. Those active cells can attack and damage organs and healthy tissue.

“This is affecting how people’s bodies create cholesterol and how they are able to regulate blood sugar and form plaque,” Rajagopal said.

Some studies have suggested the Mediterranean diet helps combat chronic inflammation because of its emphasis on fruits, vegetables and legumes, which contain antioxidants and other beneficial compounds.

Regular use of extra virgin olive oil may also help reduce inflammation and lower blood pressure, according to a review of research published in June. But it’s not enough on its own.

“If someone is having McDonald’s and drinking a lot of soft drinks, but they’re using olive oils, I don’t think you’re going to get the same benefit as someone who’s really embraced the overall diet,” said Kelly LeBlanc, a registered dietitian and vice president of nutrition programming at Oldways, a nonprofit that promotes sustainable eating. “There isn’t one singular dietary magic bullet or villain.”

A lower chance of developing Type 2 diabetes

Research has long linked excessive consumption of sugar to a risk of Type 2 diabetes. Because the Mediterranean diet relies on honey and cinnamon as sweeteners, and the primary source of sugar is fruit, it’s associated with a decreased risk of the disease.

An April study, which compared blood samples from more than 300,000 participants, found that those who adhered to the Mediterranean diet had a nearly 30% lower risk of Type 2 diabetes.

The effect may also be influenced by the consumption of plant-based fats from nuts, olive oil, and avocados, which can improve insulin sensitivity.

Good for your gut

The fibrous staples in the Mediterranean diet, like beans, lentils, apples and brown rice, are also associated with more regular bowel movements and lower blood pressure, cholesterol and blood sugar levels, according to the Food and Drug Administration.

These foods impact the health of the gut microbiome — the ecosystem of bacteria in our digestive systems that aids in breaking down food and extracting nutrients. The microbiome also helps defend the body against pathogens.

“Good bacteria in our gut feed off of that good fiber, and that allows them to proliferate,” Rajagopal said.

This creates a strong lining in the intestines, she added: “The more of that we have, it’s like a protection. It’s like a separate army against disease.”

The Mediterranean diet’s benefits go even further

Adhering to the Mediterranean diet may also lower the risk of death from cancer, in addition to reducing the chances of several particular types — including breast, colorectal, head and neck and lung cancers — according to a 2020 review of research.

Then there are the diet’s benefits for the mind: A March study found that adhering to a Mediterranean diet could reduce risk of dementia among seniors by almost 25%. According to the National Institute on Aging, the diet is associated with fewer signs of Alzheimer’s disease in the brain.

More research is needed to understand that link, but one hypothesis is that the antioxidants in fruits and vegetables can prevent damage to brain cells, according to a 2019 study.

Despite the Mediterranean diet’s myriad benefits, there’s a drawback: It won’t necessarily help you shed pounds quickly, since foods like olive oil and nuts are high in fat and calories. Losing weight on the diet requires regular physical activity and being careful about portion sizes.

“If you’re 50 pounds overweight, the Mediterranean diet alone won’t take off all those extra pounds,” said Dr. Walter Willett, a professor of epidemiology and nutrition at the Harvard T.H. Chan School of Public Health.

That said, the diet’s variety can make it more enjoyable to stick with than restrictive weight-loss regimens, Willett added.

 Plus, he said, when the Mediterranean is paired with regular exercise, any weight loss is more likely to be maintained.

Source: nbcnews.com