The scientifically-backed lifestyle habits to help you live healthier for longer have stayed pretty consistent for a while now: exercising, getting sufficient sleep, limiting stress—and, of course, eating well.

Now, researchers reveal the four foods you should prioritize, as eating them could help you live a very long life.

To narrow it down to the four, researchers in Spain examined two diets that take advice from the world’s Blue Zones, cities that reportedly have the highest proportion of centenarians: the Mediterranean diet and the Planetary Health Diet.

Both approaches support a high intake of foods like fruits, vegetables, whole grains, legumes, and nuts—and a moderate intake of dairy and meat (although the lesser-known Planetary Health Diet, established by scientists in 2019 with a focus on environmental sustainability, places a higher proportion size on plant-based protein alternatives like beans over meat).

“Higher adherence to both diets was similarly associated with lower all-cause mortality and with comparable low environmental impact, highlighting the substantial health and planetary advantages of adopting one of these plant-based diets,” Dr. Mercedes Sotos Prieto, lead author of the new study from the Autonomous University of Madrid in Spain, said in a press release about the results.

The study followed nearly 11,500 people recruited between 2008 and 2010 and followed up about 14 years later to assess the relationship between diet and survival rates.

Now the authors are calling out four food groups—staples of both diets—that they believe are most important when it comes to longevity and health span.

Fruits

Fruits are a cornerstone of both the Mediterranean and Planetary Health diets. They provide key nutrients, like vitamin C and A, and antioxidants, which help support immune health and reduce inflammation and cell damage.

One study found snacking on fruit instead of a packaged alternative also made people feel less stressed. Liz Weinandy, a registered dietitian at the Ohio State University Wexner Medical Center, previously told Fortune that vitamin C can protect our brain.

To digest a range of nutrients, the Mediterranean diet recommends eating two to three portions of all types of fruits each day. The Planetary Health diet recommends at least five servings of both fruits and vegetables per day.

Dairy

While dairy makes up a smaller portion of both diets, it was still associated with those who lived longer, per the study. The two diets specify the importance of low-fat or no-fat cheese and yogurts, like low-fat Greek yogurt or cottage cheese. Rich in calcium and vitamin D, dairy products support bone health. Dairy can help people feel full and be a good source of protein, helping to support age-related muscle loss. A small five-ounce cup of yogurt typically contains between 10 and 15 grams of protein (you need about 1.2 to 2 grams of protein per kilogram of bodyweight).

Fermented dairy products like kefir are also rich in probiotics and can support a healthy gut.

Unsaturated oils

Unsaturated oils, like olive and avocado oils, are a significant part of both diets. They can help support healthy cholesterol levels and support the brain.

“There is some evidence that a Mediterranean diet rich in virgin olive oil may help the body remove excess cholesterol from arteries and keep blood vessels open,” according to the American Heart Association.

Nuts

A handful of nuts has always been a great snack—and for good reason. Nuts contain healthy fats that can support heart health and reduce inflammation, are rich in fiber and protein to keep people satiated, and are high in omega-3s to support brain health (especially walnuts).

“Find the ingredients you love,” Dan Buettner, founder of the Blue Zones LLC, who has studied the diets of the longest living humans, previously told Fortune. “And if you can learn how to combine them to make something delicious, you’re on your way to eating to 100.”