Elderly residents of Japan’s 161 scenic Okinawan islands are really old. They live, on average, six to seven years longer than the average American. And the percentage of “super-agers,” people who’ve celebrated their 100th birthday, is two to five times higher than in the United States, according to researchers.

Daily exercise and close friendships are two of their longevity secrets. Genetics play a role, too. But what Okinawans eat every day also moves the needle, lowering the risk for heart disease, cancer, dementia and brittle bones, according to scientists who’ve conducted extensive studies on these islands, located between Taiwan and Japan’s main islands.

The local cuisine is packed with a wide variety of vegetables and whole grains, along with tofu and other soy products, omega-3 fatty acids, fruit and seaweed, plus small quantities of meat, eggs, poultry and  sweets — all washed down with flower-scented jasmine tea. The researchers, brothers Craig Wilcox, PhD, of Okinawa International University, and Bradley Wilcox, MD, of the University of Hawaii, who are co-authors of The Okinawa Centenarian Study and authors of “The Okinawa Diet Plan: Get Leaner, Live Longer, and Never Feel Hungry,” report that as part of a healthy eating plan, these foods have notable benefits:

Tofu, soy products and other legumes

tofu stirfryOkinawans munch about 3 ounces of tofu per day, according to a 2009 report in the Journal of the American College of Nutrition. The benefits: Soy beans and other legumes (like white, red and black beans) are rich in plant compounds called flavonoids that help protect cells from damage by destructive oxygen molecules called free radicals. They also contain isoflavones, estrogen-like compounds that the researchers say may help explain Okinawa’s low rates of breast and prostate cancer.

On your plate: Aim for two to four servings of flavonoid-rich foods daily, including tofu, soy products like miso soup, legumes or ground flaxseed. (Photo: cobraphotography/Shutterstock)

Related: Should Your Daughter Eat Soy?

Sweet potatoes, leafy greens and shiitake mushrooms 

shiitake mushroomsOkinawans munch at least six servings of veggies daily, including plenty of these superstars of the produce aisle. The benefits: Getting a wide variety is important, the researchers note, so that you take in plenty of vitamins, minerals and other beneficial plant compounds, known as phytochemicals. Be sure to include these three stand-outs.

Sweet potatoes, eaten in abundance on Okinawa, provide cell-protecting antioxidants as well as key nutrients that Americans often skimp on, including vitamins A, C, E and B6 as well as potassium, manganese, magnesium, iron, calcium and fiber, the researchers say. Leafy greens, also eaten in large quantities on Okinawa, provide antioxidants as well as phytochemicals that help protect against cancer, heart disease and diabetes. Shiitake mushrooms provide “practically no calories but are high in protein…fiber, antioxidants, and vitamins A, niacin, B12, C, and especially  vitamin D, a nutrient often lacking in the diets of older Americans,” the researchers note.

On your plate: Aim for 7 to 13 servings of vegetables a day. (Photo: zcw/Shutterstock)

Related: Power Up Your Summer Produce

Whole grains

soba noodlesSkip white bread, white pasta and crackers made from refined flour. Okinawans consume plenty of whole grains, such as soba noodles made from buckwheat. The benefits: Whole grains are high in fiber and so are more satisfying than refined grains. They also provide nutrients such as vitamin E and a smidge of good fat. This fiber-and-fat package is thought to keep blood sugar low and steady, reducing the  risk for diabetes, heart disease and even some cancers.

On your plate: Aim for seven to 13 servings a day, choosing plain grains like brown rice, oatmeal or quinoa or whole-grain products without added sugars. (Photo: hacksss/Shutterstock)

Fish and other omega-3-rich foods

fish mealCompared to the typical American diet, Okinawans eat about ten times more fish and other foods packed with inflammation-cooling, artery-pampering good fats, according to the experts. Americans instead eat more meat, processed foods and vegetable oils high in inflammatory omega-6 fatty acids. The benefits: Getting more omega-3s and fewer omega-6s helps keep levels of bodywide inflammation low, promoting a healthy heart and flexible arteries.

On your plate: Aim for one to three servings of salmon or other fatty fish, walnuts, ground flaxseed or canola oil daily. (Photo: Jozef Sowa/Shutterstock)

Related: Farmed Fish: Yay or Nay?

Calcium-rich foods

wakame seaweedOkinawans consume little dairy, but they get calcium from seaweed and veggies. The benefits: Calcium helps  keep bones strong and supports healthy blood pressure levels, too.

On your plate: The authors recommend reaching for two to four servings of low- or fat-free calcium-rich foods daily, including canned fish with the bones, fat-free yogurt and greens such as kale and collards. (Photo: yasuhiro amano/Shutterstock)

Sari Harrar is an award-winning health, medicine and science journalist whose work appears in Dr. Oz The Good Life magazine, Good Housekeeping, O--Oprah Magazine, Organic Gardening and other publications.