This Is the Best Diet for Healthy Aging, According to Science

But the study also points out which dietary habits may not be the best for healthy aging. Here’s what the research found, plus what doctors and dietitians want you to know.

What did the study find?

For the study, researchers analyzed data from the Nurses’ Health Study and the Health Professionals Follow-Up Study, specifically focusing on the diets of 105,000 adults who answered questionnaires about their eating habits between the ages of 39 and 69.

The researchers looked at eight dietary patterns, factoring in the participants’ intake of fruits, vegetables, whole grains, unsaturated fats, nuts and legumes, fish, poultry, dairy products, and ultra-processed foods.

The researchers discovered that nearly 10,000 of the participants (or 9.3%) aged in a healthy way, which they defined as meeting several cognitive, physical, and mental metrics, along with being able to reach age 70 free of chronic diseases. But the researchers found that people who ate diets that were higher in plant-based foods were more likely to experience healthy aging, regardless of whether they were physically active, smoked, or had a higher body mass index. That doesn’t mean they ate a vegetarian or vegan diet, though—they just ate more plant-based foods.

What is the best diet for healthy aging?

The study found that the Alternative Healthy Eating Index (AHEI) diet was the best for healthy aging. This diet is actually a scoring system developed by Harvard nutritionists that assigns ratings to foods and nutrients to determine how likely they are to raise your risk of developing chronic disease.

This diet is rich in vegetables, whole grains, nuts, legumes, and healthy fats. It also minimizes red and processed meats, sugar-sweetened beverages, sodium, and refined grains.

The eating plan specifically suggests aiming for five servings of vegetables a day, four servings of fruit, five to six servings of whole grains, and getting a serving a day from nuts, legumes, and vegetable protein, according to Harvard Medical School.

The study also looked at these dietary patterns:

• Alternative Mediterranean Index (aMED): An analysis of how well someone follows the Mediterranean diet, which is rich in plant-based foods, healthy fats, and lean proteins
• Dietary Approaches to Stop Hypertension (DASH): An eating plan designed to prevent or treat high blood pressure, minimize sodium and focus on fruits, vegetables, whole grains, and lean protein
• Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND): This diet aims to lower the risk of dementia, focusing on whole grains, green leafy vegetables, berries, nuts, beans, fish, and poultry
• Healthful plant-based diet (hPDI): An eating plan that focuses on fruits, vegetables, whole grains, legumes, and nuts
• Planetary Health Diet Index(PHDI): This diet encourages fruits, vegetables, whole grains, nuts, and legumes, while minimizing red and processed meats and eggs. It also tries to promote a sustainable food system.
• Empirically inflammatory dietary pattern (EDIP): A food-based index that looks at the inflammatory role of things like processed meat, red meat, fish, vegetables, refined grains, drinks, and tomatoes
• Empirical dietary index for hyperinsulinemia (EDIH): A dietary score that analyzes foods to try to predict insulin secretion and the body’s ability to manage blood sugar
• Ultra-processed food (UPF) consumption: An analysis of how much people eat of foods that are changed from their natural state, with added artificial colors and flavors, and preservatives.

Ultimately, the researchers found that people who ate diets that were higher in trans fats, sodium, sugar-sweetened beverages, and red or processed meat were less like to age in a healthy way.

“What we eat is really fundamental to all aspects of our existence—these findings highlight that,” says Scott Kaiser, M.D., a geriatrician and director of Geriatric Cognitive Health for the Pacific Neuroscience Institute at Providence Saint John’s Health Center in Santa Monica, CA. “We need food for nutrition, sustenance, and survival. At the same time, food can be our medicine or extremely toxic.”

Why can a plant-based diet help you live longer?

Again, plant-based doesn’t mean you can’t have meat. Instead, it just means that the majority of the foods you eat come from plants. There are a few reasons why plant-based diets are linked to healthy aging.

“Studies have shown that a plant-based diet may help you live longer by lowering the risk of chronic diseases like heart disease, diabetes, and certain cancers due to its high fiber, antioxidants, and anti-inflammatory compounds,” explains Marta Guasch-Ferré, Ph.D., study co-author and an associate professor at University of Copenhagen.

Plant-based diets also support a healthy gut, promote weight management, and protect cells from oxidative stress, which can lead to cell and tissue damage, Guasch-Ferré says. “Additionally, it lowers inflammation and improves brain health, reducing the risk of cognitive decline as you age,” she adds.

But there can also be an indirect impact on healthy eating when you follow a mostly plant-based diet. “People increasing plant foods often also reduce ultra-processed foods,” says Scott Keatley, R.D., of Keatley Medical Nutrition Therapy. “That makes it hard to separate whether the benefit is from eating more plants, eating less junk, or both.”

Minimizing ultra-processed foods is important, too

The study found that eating higher amounts of ultra-processed foods was linked to a 32% lower chance of healthy aging.

“Ultra-processed foods are consistently linked to worse health outcomes,” Keatley says. “They’re engineered to override hunger cues, they drive inflammation, and they crowd out nutrient-dense foods.”

Ultra-processed foods also tend to be higher in salt and sugar, ingredients that have been linked to health issues, too, Guasch-Ferré says.

Why is eating well in mid-life so important?

The study specifically focused on how dietary patterns in mid-life impacted quality of life down the road. Guasch-Ferré says mid-life is a “critical window” for long-term health.

“It’s when the foundations of chronic disease are often laid—quietly and cumulatively,” she says. Vascular damage, low-grade inflammation, insulin sensitivity issues, and oxidative stress can also take hold during this time, and following a healthy diet may help to combat them, Guasch-Ferré says.

“A nutrient-dense, lower-inflammatory diet during mid-life can slow or even prevent these changes before they become fixed,” she says. “It’s much harder to rebuild resilience at 70 than it is to preserve it at 50.”

What else can you do for healthy aging?

Following a plant-based diet is just one thing you can do to boost longevity. Here’s what else Dr. Kaiser recommends:

• Stay physically active
• Avoid smoking
• Do your best to manage stress
• Minimize or avoid alcohol
• Keep your brain active
• Socialize regularly
• Get good, regular sleep
• Have regular medical check-ups

But Guasch-Ferré also suggests keeping this in mind when it comes to aging in the best way possible: “Long-term habits, not short-term fixes, are what shape healthy aging.”