Adding this one simple food to your diet may help you live to 100, according to the world's longest-living people

A few years ago, I traveled to Okinawa in Japan, Nicoya in Costa Rica, Ikaria in Greece, Loma Linda in California and Sardinia in Italy — all "Blue Zones," or homes to the longest-lived people — to find out what centenarians ate to live to 100.  

I also asked dozens of the world's leading nutritionists and food scientists what we should eat to enjoy a long and healthy life, while also taking care of the environment.

One conclusion leaped out like a flashing neon sign (and might come as a shock to fans of the latest trendy diets): Of the top 10 recommended foods, half belonged to the bean family — lentils, soybeans, peanuts, chickpeas and black beans.

On Costa Rica's Nicoya Peninsula, for example, the day might begin with a warm corn tortilla stuffed with savory black beans. On the Italian island of Sardinia, lunch might be a steaming bowl of minestrone, packed with fava beans, cranberry beans and chickpeas. On the Japanese island of Okinawa, dinner might include a tasty stir-fry with green beans, soybeans or mung bean sprouts.

Coincidental? I don't think so. A 2004 study of people 70 years or older in three different cultures around the world found that for every two tablespoons of beans a day individuals consumed, they reduced their risk of dying by 8%.

Other research has shown that beans not only provide the complex carbohydrates, proteins and trace minerals our bodies need, they also supply the fiber our microbiomes require, boosting our immune systems. That makes sense, because Blue Zone residents don't achieve their extraordinary longevity by relying on superior genes alone, but also by avoiding obesity, diabetes, heart disease, dementia and cancers better than the rest of us.

By contrast, nearly two thirds of Americans now report themselves to be overweight or obese, according to Gallup. And according to a recent Harvard study, we have a shorter average life expectancy than residents of nearly any other high-income nation — largely because of our diets and lifestyles.

In every Blue Zone I've ever visited, generations of cooks have made beans a key ingredient in their most popular recipes.

Here are a few to make in your own kitchen:

TENDER BEAN, POTATO AND ONION STEW

Featured in almost every Nicoyan meal, black beans contain high levels of anthocyanins and have 10 times the antioxidants of an equivalent serving of oranges. Rich and hearty, this one-pot meal is a staple in Costa Rica. It's easy to make and costs less than $1 a serving.

Cook time: 1 hour
Servings: 6

Ingredients:

• 1 lb. dried kidney beans, soaked overnight (or three 15-oz. cans, drained)
• 1 cup low-sodium vegetable broth
• 1 chayote squash, diced
• ½ carrot, peeled and diced
• 3 red, orange or yellow sweet peppers, seeded and diced
• 2 large potatoes, peeled and diced
• 2 tsp. chopped cilantro
• 1 small onion, diced
• 2 cloves garlic, minced
• Salt and pepper (optional)

Steps:

1. If using dried beans, drain and rinse the beans; discard the soaking water.
2. Place beans in a large pot and add vegetable broth. Add water, as necessary, to cover beans.
3. Bring broth to a boil; then immediately turn down to simmer.
4. Cook for 25 minutes.
5. Stir in the rest of ingredients; cook for about 25 more minutes, or until beans are tender, stirring occasionally to keep from burning.
6. Add salt and pepper to taste before serving. Enjoy alone or with tortillas or rice.

CHICKPEA SOUP WITH LEMON AND HERBS

Greeks and Ikarians especially have mastered the art of blending lemon, olive oil and herbs. This simple recipe is a warming alternative to chicken soup in the winter and provides yet another way to creatively incorporate beans into your daily diet.

Cook time: 2 hours, 20 minutes; 45 minutes if using canned chickpeas
Servings: 6

Ingredients:

• 1 lb. dried chickpeas, soaked overnight, rinsed and peeled (or four 15-oz. cans low sodium chickpeas, drained)
• 1 medium onion, coarsely chopped
• 1 garlic clove, minced
• 1 bay leaf
• ½ cup extra-virgin olive oil, plus more for serving
• Salt and pepper (optional)
• Juice of three lemons, for serving

Steps:

1. Place chickpeas in a pot with just enough water to cover; bring to a boil.
2. Remove from heat, drain, rinse and put into a clean pot.
3. Add onion, garlic, bay leaf, olive oil, and enough water to cover the ingredients. Stir to combine.
4. If using dried chickpeas, bring to a boil; then simmer for about 2 hours, or until chickpeas are soft.
5. If using canned, bring to a boil, then simmer for 30 minutes; add a few tablespoons of water at a time to thin the soup as needed.
6. Remove from heat and discard bay leaf. Add salt and pepper to taste.
7. Serve with generous drizzles of lemon juice and olive oil.

BLACK-EYE PEA SALAD WITH MINT AND ONIONS

This recipe represents one of my fondest revelations from cooking in Ikaria. I would never have thought to pair beans with vinegar and mint, but the result was a symphony of new and magical flavors. The vinegar not only adds the healthful digestion and immunity-boosting effects of fermentation and probiotics, but also helps maintain the texture of the beans so they don't disintegrate as leftovers.

Cook time: 1 hour if using dried beans; 10 minutes with canned beans
Servings: 8

Ingredients:

• 1 lb. black-eyed peas (or four 15-oz. cans, drained)
• 3 green onions, tops removed and coarsely chopped
• 1 carrot, peeled and grated
• 3 tablespoons red wine vinegar
• 1 cup mint, chopped
• ½ red onion, chopped
• 1 cup greens like spinach, baby kale, or sweet dandelion, chopped
• ¼ cup extra-virgin olive oil
• Salt and pepper (optional)
• Dill (optional for garnish)

Steps:

1. If using dried black-eyed peas, place them in a pot and cover with water. Bring to a boil; then reduce to a simmer and cover with a lid, tilting lid slightly to let some steam escape.
2. Cook for an hour, or until peas are tender.
3. While black-eyed peas are still hot and steaming, mix all the ingredients together in a large bowl, tossing to combine. Add salt and pepper to taste.
4. If using canned black-eyed peas, just drain, rinse, and heat on stovetop over medium heat with all other ingredients until warmed through (5 to 6 minutes).
5. Garnish with dill, if using.
6. Serve warm or cold.

SWEET POTATO BLACK BEAN BURGER

This burger is a longevity powerhouse. Loaded with beans, greens, sweet potatoes and pepitas, it's the perfect example of a Blue Zones–inspired twist on a classic American comfort food.

Cook time: 35 minutes
Servings: 4

Ingredients:

The Patty and Buns:

• 1½ cups rolled oats
• 1 cup peeled, mashed, cooked sweet potato
• 1 cup mashed black beans
• ½ tsp. salt
• 2 tsp. onion powder
• 1 tsp. ground cumin
• 1 tsp. smoked paprika
• ½ tsp. black pepper
• ½ tsp. chipotle powder (optional)
• Oil for cooking
• 4 whole wheat burger buns

The Sauce:

• ¼ cup toasted pepitas
• ¼ cup good-quality salsa verde

The Toppings:

• 1 avocado, sliced
• ½ cup loosely packed sliced kale
• Pickled or thinly sliced raw red onion*

Steps:

1. Make the patties: Pulse the rolled oats in a food processor until coarsely ground and set aside.
2. Combine the sweet potato, black beans, salt and spices; then incorporate the ground oats. Let this sit for about 5 minutes so flavors can marry.
3. Form the mixture into 4 patties. In a skillet, heat a thin layer of oil over medium heat.
4. Add the patties and fry on both sides until crisped, about 4 minutes per side.
5. Make the sauce: Puree the pepitas and salsa verde in a food processor or blender and set aside.
6. Build your burger: Mash the avocado and spread on the bottom bun. Then, add your patty and top with the pepita sauce. Finish off the burger with kale and red onion, then the top bun.
7. *To pickle red onions, submerge them in white vinegar with a generous pinch of salt for at least 6 hours.

On top of being good for you, beans are cheap to produce and grow practically everywhere, from equatorial zones to northern regions, so they don't need to be transported vast distances to reach markets. They also don't require refrigeration and can be stored for a long time.

Beans are even healthy for the land itself, because they restore crucial nitrogen to the soil. Accounting for the environmental impacts of what we eat has become more urgent as Earth's climate crisis has worsened. The global food system now contributes more than a quarter of all greenhouse gas emissions, primarily from livestock production.

Shifting our diets to favor plants over meat could be so important. If people followed standard dietary guidelines, we could reduce greenhouse gas emissions from food production by as much as 70%, according to a team from the University of Oxford.

So, what's the bottom line? Can we be good to both ourselves and the planet? Our research suggests we can. And the first step on that quest to achieve a long healthy life should be to embrace the simple magic of beans.

Dan Buettner is a longevity researcher, National Geographic Fellow and award-winning journalist. He is the author of "The Blue Zones: Lessons for Living Longer from the People Who've Lived the Longest" and "The Blue Zones Solution: Eating and Living Like the World's Healthiest People." His latest bestseller, "The Blue Zones Kitchen: 100 Recipes for Living to 100," fuses scientific reporting, National Geographic photography and recipes that may help you live to 100. Follow him on Instagram @danbuettner.

Don't miss:

• Japanese doctor who lived to 105—his spartan diet, views on retirement, and other rare longevity tips
• The world's longest-living people share this hobby—why studies say it can help add years to your life
• This 30-year Harvard study found the 5 simple habits that may prolong your life by a decade or more

Check out: Americans spend over $5,000 a year on groceries—save hundreds at supermarkets with these cards