5 breakfast staples linked to longer life, eaten by the healthiest people in the world

Buettner, who is the author of upcoming book The Blue Zone American Kitchen, said that the first Blue Zone in Loma Linda, California is actually the original breakfast cereal.

Seventh-day Adventist John Kellogg, he said, was the first person to discover and promote whole grain wheat flakes and corn flakes as breakfast food. Kellogg invented the cereal as an easily digestible breakfast food, according to the Smithsonian Magazine. The idea to put sugar in the cereal and market it to the general public was Kellogg's brother's idea.

A high concentration of Seventh-day Adventists live in Loma Linda, Buettner said, and members of the church eat very little animal products, don't smoke or drink alcohol, according to Healthline.

Nutritionist Stacey Simon said that whole grain cereal without added sugar can be a great choice in the morning, especially when paired with a healthy fat or protein for extra nutrients.

"Whole grains contain fiber, vitamins (especially B vitamins), and minerals. Whole grains have been shown to reduce the risk of heart disease, certain types of cancer, and diabetes," she said.

Buettner said that people in the Okinawa Blue Zone usually eat a miso soup for breakfast with root vegetables and tofu.

The meal was traditionally made with a purple sweet potato, he said, that was steamed or sauteed with garlic, sesame oil, and green onions. He said the meal was also often made with brown rice, he said, but is also eaten with white rice and usually consumed with green tea.

This breakfast is full of vitamins and minerals from the variety of vegetables, Simon said. Tofu is high in vitamins and protein, she said, but low in saturated fat, which has been linked to heart disease.

Green tea has been shown to have a variety of benefits including decreasing your risk for heart disease, lowering cholesterol, improving gut health, and lowering blood sugar levels. Simon said green tea can also help reduce inflammation.

Ikarians typically eat a goat's milk yogurt, Buettner said, topped with nuts and honey for breakfast. This yogurt, he said, is often eaten with bread and seasonal fruit. He said they will also have rotation of herbal teas, such as oregano tea, rosemary tea, sage tea, and catnip tea.

Goat's milk contains more protein than cow's milk and may help the body absorb other essential nutrients, according to Healthline. Nuts are also a great source of protein and healthy fats, as Insider's Gabby Landsverk previously reported.

Simon said that teas like those consumed in Ikaria can help lower inflammation.

Breakfast is not considered a very important meal in Sardinia, Italy, Buettner said, so many Sardinians start their day with a lunch-style dish: often a minestrone soup, consisting of vegetables, pasta, beans, and Parmesan. The soup is eaten with sourdough bread and sheep's milk cheese as well as some black coffee.

He said minestrone soup is one of his favorite breakfasts to have because of its high fiber content from the beans and vegetables. This fiber helps feed the bacteria in your gut, he said, which can benefit your digestion and immune system.

Simon said that sheep's milk from grass-fed sheep contains omega 3 fatty acids which can help prevent heart disease. Sourdough bread also doesn't spike your blood sugar like the white bread commonly eaten in the US, she said.

The final Blue Zone breakfast is from Costa Rica, where Buettner said people commonly eat black beans cooked with garlic, onions, and a bay leaf with whole grain corn tortillas on the side. He said rice, avocado, and sometimes papaya are included.

"Black beans are high in fiber, protein, folate, potassium, and antioxidants, and though they are carbohydrates, they actually do not cause a spike in blood sugar levels like rice or tortillas alone might," Simon said.

Avocados are high in healthy fats, she said, which can help reduce the risk of heart disease and reduce inflammation.

She said papaya is a great source of vitamin C and can help promote digestion. Coffee can also reduce your risk for developing liver cirrhosis, cancer, and Alzheimer's disease, she said.