The 4 Best Diets for Longevity (and Why They Work)

There's no dearth of diets out there. But if your goal is to ward off chronic diseases and live a longer, healthier life, certain diet plans rise above the rest.

Here, registered dietitian Amanda Holtzer, RD, dishes on the four best diets for longevity to help keep you hale and hearty into your golden years.

"As a dietitian, if I had to choose one 'diet' to encourage my patients to follow, it would be the Mediterranean diet," Holtzer says.

Not exactly a "diet" — it doesn't restrict calories nor was it designed for weight loss — the Med diet is simply a pattern of eating followed by people who live in the countries bordering the Mediterranean Sea, she explains.

In the Mediterranean diet, plants — including fruits, vegetables, beans, legumes and whole grains — make up most of your diet, Holtzer says. Fish, dairy, eggs and poultry are enjoyed in moderate amounts while red meat, refined sugars and processed foods are very limited.

"The Mediterranean diet is also big on healthy fats, but not in a ​restrictive, keto-ish, eat-tons-of-fats-and-no-carbs​ type of way," Holtzer says.

"Rather, it encourages us to incorporate more polyunsaturated fats in the form of extra-virgin olive oil, avocados, nuts and seeds."

"Because of its emphasis on plants, the Mediterranean diet is extremely high in antioxidants and anti-inflammatory foods," Holtzer says. "Since inflammation is the root of many chronic diseases (think: diabetes, obesity, heart disease and cancer), it stands to reason that this diet is excellent for disease prevention and overall health."

Specifically, the inclusion of healthy fats may serve a protective function for your heart. In fact, an April 2020 study in the ​​Journal of the American College of Cardiology​​ found that having just a 1/2 tablespoon of olive oil daily (in place of an animal-based fat like butter) is linked to a lower risk for heart disease.

Similarly, research shows that the Mediterranean diet is linked to improved cardiovascular risk factors such as high blood pressure and cholesterol, per an April 2020 meta-analysis in ​​The BMJ​​.

What's more, "the high fiber content of this diet promotes blood sugar stabilization (a key for diabetes prevention) as well as digestive regularity, which can serve to prevent many diseases, including but not limited to high cholesterol, constipation, irritable bowel syndrome and ulcerative colitis," Holtzer says.

Plus, the Mediterranean diet, which encourages eating lower-calorie foods (like fruits and vegetables), can support weight loss, Holtzer says. Case in point: A March 2019 review in ​​Nutrients​​ found that the Med diet is associated with weight loss, lower body mass index and smaller waist.

"Another one of my personal favorites is the Blue Zones diet," Holtzer says. "Again, this isn't really a diet, so much as a way of life for certain regions of the world."

This healthy form of eating is inspired by the five blue zones — Okinawa, Japan; Sardinia, Italy; Nicoya, Costa Rica; Ikaria, Greece and Loma Linda, California — places in the world with the longest lifespans and the lowest rates of chronic disease.

These "longevity hotspots" were identified by Dan Buettner, the founder of Blue Zones. In his research on centenarians (people who live to the age of 100 or older) Buettner noticed certain lifestyle trends in these five regions that seemed to account for the inhabitants' long, healthy lives, Holtzer says.

He pinpointed nine specific habits that these regions commonly shared — referred to as the Power 9 — which include tenets such as moving naturally, having a sense of purpose, putting family first and nurturing social relationships, Holtzer says. Diet is also a central focus of the Blue Zones way of life.

The diet is 95 to 100 percent plant-based (think: veggies, beans and nuts) with a focus on minimally processed, mostly single-ingredient foods and healthy hydration habits (about 7 glasses of water per day), Holtzer says.

It limits dairy, eggs, sugar and meat and permits a moderate intake of fish, she says.

People who adhere to the Blue Zones diet also follow the 80 percent rule — you stop eating when your stomach is 80 percent full — and enjoy one to two glasses of wine per day, Holtzer adds.

Like the Mediterranean diet, this eating plan is also heavily plant-based with lots of fiber, antioxidants and anti-inflammatory foods. That means it similarly helps reduce inflammation and promotes healthy weight loss as well as gut and heart health.

Another thing that's particularly valuable about the Blue Zones lifestyle is that it doesn't place all value and pressure on diet, but rather concentrates on all aspects of health including physical activity, social relationships, community, personal fulfillment, spirituality and stress management, Holtzer says.

"The people who abide by this diet do not work 9-to-5 jobs they hate; they don't 'grind' all day and all night. Instead, they rest, they recharge, they practice gratitude and they place tremendous value in their spirituality," Holtzer says.

The stress management component is especially important for longevity. "By now, we know that stress is one of the leading causes of inflammation," Holtzer says. So by making stress reduction a prominent pillar of your lifestyle, you can help reduce and prevent chronic inflammation, which increases your risk for certain long-term diseases.

"The Japanese diet is another heavy hitter when it comes to whole foods and balanced eating," Holtzer says. Indeed, "the Healthiest Countries 2021 report named Japan — which has the lowest rates of obesity in the globe — as the fourth healthiest country in the world," she says.

What's more, Japanese people lead the international community in life expectancy with an age of 84.4 years, according to the Organisation for Economic Co-operation and Development.

The key players in this diet are fruits and vegetables, fish, soybeans, fermented foods and green tea with a limited amount of red meat, processed foods and added sugar, Holtzer says.

Another crucial factor of the Japanese diet is small portion sizes. "Rather than three large meals per day, this diet encourages small, frequent meals of equal size throughout the day," Holtzer says.

By eating small frequent meals, we help stabilize our blood sugar levels throughout the day, Holtzer says. Fiber-rich soybeans, which serve as a prime source of plant-based protein in the Japanese diet, also function to steady blood sugar.

Not only does blood sugar stabilization keep our appetite in check and curb overeating, but it can also help prevent insulin resistance, one of the key precursors to obesity, diabetes and heart disease, Holtzer explains.

The Japanese diet also relies heavily on fermented foods, such as miso (fermented soybeans/legumes), Tsukemono (pickled veggies including cucumber, daikon and carrots) and Umeboshi (fermented Japanese plums). And because fermented foods are rich in probiotics (good bacteria that live in our bodies and protect us from bad bacteria), they play a large role in our immunity and disease prevention, she explains.

And once again, the plant-forward focus of this diet means that it's high in antioxidants and anti-inflammatory foods, which help prevent chronic inflammation in the body that may contribute to disease.

The DASH diet, which stands for Dietary Approaches to Stop Hypertension, was ranked the number two diet overall and the number one diet for healthy eating by the U.S. News and World Report in 2021.

And it's designed to do exactly what it says: stop or prevent high blood pressure, Holtzer says.

Over time, high blood pressure damages the tissues inside the arteries and blood vessels, making them more firm and rigid, which decreases blood flow and delivery of oxygen to the heart and body, Holtzer explains.

So if you're looking to lower your blood pressure and improve your heart health, the DASH diet may be the right eating plan for you.

Like other healthy eating plans, the DASH diet encourages a high intake of fruits, vegetables, whole grains, lean proteins and low-fat dairy products while limiting red meat, processed meats, full-fat dairy, refined oils and foods high in sugar and sodium, Holtzer says.

"What makes the DASH diet different is its emphasis on sodium," Holtzer says. This diet sets a cap on daily sodium, which ranges from 1,500 to 2.300 milligrams daily, depending on the person and the severity of their hypertension. For reference, 2300 milligrams is equivalent to about one teaspoon.

With its focus on fruits, vegetables and whole grains, this diet is high in fiber, antioxidants and other nutrients (including potassium, magnesium and calcium) that assist the body in ridding itself of excess fluid that contributes to high blood pressure, Holtzer says.

A January 2021 systematic review in the ​Journal of Hypertension​ found that the DASH diet was associated with the largest decreases in blood pressure, even when compared to other plant-based diets (including the Mediterranean diet).

And by limiting foods high in sodium, saturated fats and processed sugars — which exacerbate high blood sugar levels and contribute to weight gain — the DASH diet is linked to helping reduce your risk of obesity, insulin resistance and inflammation, Holtzer says.