The cheap, unprocessed longevity smoothie a Blue Zone nutrition expert makes every morning

• Breakfast smoothies are a hit with many longevity experts.
• A Blue Zone doctor shared one of the simplest recipes: a blend of leftover nuts and fruit.

Dr. Joan Sabate views breakfast as a daily opportunity to fuel up on some of the most important nutrient-dense food groups that support healthy longevity. His strategy is dirt cheap, too.

Sabate, a healthy eating expert so esteemed in nutrition circles that he was tapped to develop the federal diet recommendations that are now in use across the US, says it needn't be time-consuming or expensive to enjoy a healthy breakfast. He lives in America's only longevity Blue Zone, where healthy eating is made easy by a mix of religious habits and local regulations that support consistent nutrition and exercise routines.

At home with his wife of 45 years, Sabate has developed a trick for making effortless, nutrient-dense breakfast smoothies. His "fruit shake," as he calls it, involves a few leftovers plus protein and healthy fats that keep him going for hours.

"What we have is basically a simple meal," Sabate, a professor of nutrition and epidemiology at Loma Linda University School of Public Health in California, told Business Insider. "It is not sophisticated — we don't eat ultra-processed foods."

A blender full of fruit and nuts is his longevity recipe

Sabate's fruit shake recipe fluctuates depending on the season, and what's available at his local market in the Los Angeles suburbs. But it always involves two core ingredients — leftover fruit (especially the overripe stuff that's about to go bad) and two heaping handfuls of nuts.

Usually he chooses walnuts, a favorite of many longevity experts because they're rich in fatty acids that are good for your brain and heart. He also tends to include a little bit of fresh squeezed orange juice to get the mixture just right.

"That's a quick way to eat a lot of fruit, and maybe two servings of nuts," he said. Throughout the rest of the day, he'll round out his diet with vegetables, whole grains, and legumes like beans, which are another Blue Zone staple.

Sabate knows science backs up his strategy. He has pioneered decades of clinical research demonstrating how nuts can improve human heart health, and he is researching how nuts may also ease other chronic issues, including the inflammation and cognitive decline that often comes with aging.

He is also aware that fruits are nutritional powerhouses that support healthy aging. Studies suggest regular berry eating may even help combat cognitive decline. The benefits of these foods go beyond what's listed on a back-of-the-box nutrition panel, and can't be divided up neatly into the three basic macronutrient categories of carbs, protein, and fat.

"We don't eat macronutrients," he said. "We eat foods, and the foods carry with them many other nutrients."

Nuts have lots of healthy monounsaturated fat, plus a good dose of protein.

"Besides that, they have minerals, they have vitamins, and they have phytochemicals," he said.

Nuts are nature's protein powder

To keep things interesting, Sabate's wife likes to top off their smoothies with a sprinkle of crunchy cacao nibs for added texture and flavor.

Sometimes, he might also add a plop of yogurt, for a calcium bonus, but he doesn't ever try to boost his smoothies with protein powders, supplements, or vitamin mixes. He's confident he can get what he needs from eating whole foods rich in protein and filled with fiber and other health-propelling properties.

"We don't use soy protein or any of these foods that are already powder," he said. "Just nuts as nature has created it, and fruit."