"Beans reign supreme in the blue zones and are the cornerstone of every longevity diet in the world.”

While a lot of health factors feel uncontrollable, diet is completely in our hands and plays a crucial role in longevity. Even small tweaks to how we eat can impact our lifespan.

Dan Buettner, a National Geographic fellow, founder of Blue Zones LLC, and author of The Blue Zones American Kitchen: 100 Recipes to Live to 100, has studied the daily habits of those who live in blue zones where people live about a decade longer than the average (think, Sardinia, Italy; Okinawa, Japan; and Ikaria, Greece).

After collecting his research and distilling some of the lessons of the blue zones to his book, Buettner says the advice can be applied to your weekly grocery run—and it’s easier than you may think.

Bottom line: “put your whole-food plant based glasses on and walk through your grocery store,” Buettner tells Fortune.

With this basic principle in mind, focus on ingredients you find tasty.

“Find the ingredients you love, and if you can learn how to combine them to make something delicious, you’re on your way to eating to 100,” he says.

Here are the five foods Buettner says represent the blue zone way of life:

Beans

Beans uniquely offer a mix of protein and fiber, beneficial for muscle building and maintaining a steady blood sugar. They also contain folate and magnesium, crucial for cell growth and muscle growth respectively. The majority of Americans do not get enough fiber in their diet, and Buettner points to the microbiome’s dependence on fiber to function properly. A cup of beans provides about half of your daily fiber recommendation.

You can find beans for less than $2 a pound, he says, making them an accessible addition to any diet.

In his book, Buettner recommends eating beans every day, writing they “reign supreme in the blue zones and are the cornerstone of every longevity diet in the world.” 

Nuts

Eat a handful of nuts a day, Buettner says, whether they are almonds, pistachios, walnuts or cashews, to name a few. They contain protein and fiber and can reduce the risk for high blood pressure, heart disease, and inflammation.

Whole fruits and leafy greens

One key to eating like you live in a blue zone is eating a variety of whole fruits and vegetables every day, specifically adding in leafy greens, which are filled with vitamins.

“People in the blue zones eat an impressive variety of garden vegetables and leafy greens (especially spinach, kale, beet and turnip tops, chard, and collards) when they are in season; they pickle or dry the surplus to enjoy during the off-season,” Buettner writes in his book.

Maintaining lasting changes to diet only works if people stick with their habits. And you’re more likely to maintain a habit if you enjoy it. Regularly seeking out your favorite vegetable and fruit during your grocery run can take the stress out of purchasing things you aren’t excited about.

Sweet potatoes

Sweet potatoes contain complex carbohydrates and protein, not to mention they are cheap and accessible, Buettner says. They are packed with vitamins crucial for strengthening the gut microbiome, which helps with digestion and strengthens the immune system.

Turmeric

Turmeric, a common ingredient found in curries, is a major anti-inflammatory spice, and has been used to treat digestive issues, liver problems, and wounds.

“And turmeric impacts the hippocampus, which is a part of the brain that helps regulate stress hormones,” Dr. Uma Naidoo, a Harvard-trained nutritional psychiatrist and author of This Is Your Brain on Food, previously told Fortune. It can help prevent chronic stress which can lead to heart problems.

Consider adding the spice to your next cup of tea.

Buttner hopes people see that eating in a way that promotes health and longevity is not out of reach.

“People tend to think [of] the expensive super foods, or even expensive fresh produce, which is out of reach for a lot of Americans,” he says. “In a blue zone, people are eating peasant food, so they’re eating the beans and the greens that are growing in vacant lots and whole grains, which are cheap. You can buy those in bulk.”