What's the Best Diet for Longevity?

How to eat to live a longer and healthier life.

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Hacking one’s health in the name of longevity can often lead to an unyielding assortment of trends, takes, and tips each one more unaligned with each other. Do a cold plunge. Sit in a sauna. Walk 10,000 steps a day. Bryan Johnson, leader of the Don’t Die regime, pops supplements like candy—but, of course, he’s not eating any candy.

When it comes to eating, and specifically how what we eat affects how long we live, the information out there regarding any links between diet and longevity can be equally conflicting. Some people will tell you to eat lots of meat. Others are on record saying that isn’t exactly the case. (“Meat is like radiation,” Walter Willett, a Harvard T.H. Chan School of Public Health nutrition researcher, once said. “We don’t know the safe level.”)

Walter Longo, director of the Longevity Institute at the University of Southern California, even spells out precisely what to do if you want to live a long time. It’s right there on his website, where the first line reads, “Eat mostly vegan.” Protein intake? Low. When to eat? Stick to a fasting diet, confining all meals between 8 a.m. and 8 p.m.

What, you might ask, are we supposed to do then, if the idea is to optimize a diet in the name of our health so that we can live a long, healthy life?

“Certainly there is no one-size-fits-all diet that’s best for everyone,” says Dr. Frank Hu, Harvard professor of nutrition and epidemiology. “The good news is there are different patterns that can help prevent chronic disease and improve longevity.”

Keep It Real

By far, the overarching principle across all diets, if you’re looking to live a long life mostly free of disease, should be the elimination of ultraprocessed foods. Packaged snacks, cookies, fast-food burgers, soda—all are examples of the sort of food that will do more harm to your body, regardless of how good a sleeve of chocolate chip cookies might taste in the moment.

“Nowadays ultraprocessed foods are everywhere and ubiquitous in our food supply, but they’re very high in sugar, sodium, and unhealthy fats,” says Hu.

Visit the Old Country

The Mediterranean Diet is commonly promoted as one of the best diets out there for preventing chronic disease and preserving cardiac health. Limiting the intake of dairy products while upping the amount of fish and foods high in omega-3s, are two guidelines of the diet.

Meanwhile, the diet’s other key feature is paying attention to the types of fats and carbs you eat as opposed to eliminating them entirely. Consuming extra virgin olive oil is a big part of eating like you’re in Italy. “It’s not just beneficial in terms of lowering your cholesterol,” Hu says. “It may prevent other chronic diseases, like dementia or Alzheimer’s.”

Red meat doesn’t need to be totally eliminated. If you’re a person who likes cooking up a steak every now and then, keep it to something like a strip or a flank, which are both lean cuts that contain key nutrients like zinc, heme iron, and B vitamins.

Go Blue

Blue Zones around the world—Okinawa and Sardinia, for instance—are famed for the exceptionally long lives of their inhabitants. People there, who tend to get regular physical exercise and lead rich social lives, are known for living well past 80. Their diets are generally a 95-5 split. That is, just 5 percent of their meals contain any animal protein, while 95 percent of their diets are composed of plant-based foods. In Loma Linda, California, where more people 100-plus years old live than anywhere else in the world, vegetarian diets are in, and alcohol is out. So is caffeine.

The Adventist Health Study 2, which has followed 96,000 Americans and Canadians since 2002, shows that people who eat vegetarian or mostly vegetarian diets have lower levels of cholesterol and high blood pressure, as well as lower prevalence of type 2 diabetes.

As Hu says, however, that doesn’t mean you need to radically change your diet. What the Blue Zones have in common is that they follow a key principle.

“You don’t have to follow a rigid regimen,” he says. “Basically, you want to eat minimally processed and whole foods: fruits and vegetables, whole grains, nuts, legumes, and seeds.”