The Foods That Keep Showing Up Where People Live Well
Nutrition has become unnecessarily complicated. We have continuous glucose monitors, ketone meters, genetic testing, microbiome sequencing, supplement cabinets large enough to require zoning permits, and enough dietary tribes to populate a small country.
Meanwhile, some remarkably ordinary foods keep showing up in populations that live long and remain healthy: whole grains, green vegetables, tubers and beans.
Not powders made from them. Not extracts standardized to 37 percent something-or-other. The foods themselves.
Oats. Barley. Brown rice. Kale. Spinach. Potatoes. Sweet potatoes. Lentils. Chickpeas. Black beans.
Grandmother’s food. And increasingly, modern nutritional science is discovering that Grandma may have been running a metabolic laboratory in her kitchen.
Whole Grains Still Wearing Their Clothes
There is an enormous physiological difference between a kernel of wheat and a piece of white bread, even though both can legally introduce themselves as carbohydrates.
An intact whole grain contains the bran, germ and endosperm, bringing along fiber, magnesium, vitamin E, B vitamins, polyphenols and numerous other phytochemicals. Refining removes much of this architecture and creates something the human digestive tract can dismantle considerably faster.
Whole grains slow digestion, improve satiety and deliver fermentable material to the intestinal microbiome. Their fiber can increase production of short-chain fatty acids such as butyrate, molecules increasingly recognized as intermediaries between intestinal bacteria and human physiology.
And the epidemiology is remarkably consistent.
A meta-analysis of 14 prospective studies involving 786,076 people and nearly 98,000 deaths found that people consuming the most whole grains had a 16 percent lower risk of total mortality and an 18 percent lower risk of cardiovascular mortality compared with those consuming the least.
Another dose-response meta-analysis involving more than 2.2 million participants found that three additional servings of whole grains per day were associated with a 17 percent lower risk of all-cause mortality and approximately a 25 percent reduction in cardiovascular mortality. A more recent analysis similarly found that each additional 30 grams of whole grain per day was associated with lower cardiovascular and all-cause mortality.
The important word, however, is whole. A blueberry muffin does not become health food because somebody sprinkled oat bran on its roof.
Greens Are Edible Biochemistry
Then there are the greens.
Spinach, kale, chard, arugula, collards, broccoli and their relatives look almost embarrassingly virtuous. They are nutritional overachievers containing folate, magnesium, potassium, carotenoids, vitamin K, vitamin C, polyphenols and fiber.
Many leafy vegetables also contain substantial amounts of dietary nitrate. That nitrate is interesting. Oral bacteria convert nitrate toward nitrite, which can ultimately contribute to nitric oxide production. Nitric oxide helps regulate vascular tone, endothelial function and blood pressure. Apparently salad knows some cardiovascular physiology.
Green vegetables also provide phytochemicals that influence oxidative signaling, inflammation and cellular defense systems. Cruciferous vegetables add glucosinolates and compounds such as sulforaphane to the biochemical stew.
A meta-analysis examining green leafy and cruciferous vegetables found that higher intake was associated with approximately a 16 percent reduction in cardiovascular disease incidence.
No single molecule deserves all the credit. That is probably the point. A leaf is not a vitamin pill with chlorophyll attached.
The Potato Deserves a Retrial
The potato has suffered a peculiar nutritional humiliation.
We took a perfectly respectable underground vegetable, peeled it, sliced it, submerged it in industrial cooking oil, covered it with salt, sold it beside a cheeseburger and then blamed the potato.
Actual tubers – potatoes, sweet potatoes, yams and similar root foods – provide potassium, vitamin C, vitamin B6, fiber and, depending upon the variety, carotenoids and polyphenols.
The epidemiology here is more complicated than it is for whole grains, and that is worth acknowledging. A systematic review found no significant association between ordinary potato consumption and all-cause, cardiovascular or cancer mortality. A more recent analysis of seven prospective cohorts likewise found no increased cardiovascular risk from total potatoes or from baked, boiled and mashed potatoes, although fried potatoes were associated with a modestly greater risk of hypertension.
Then there is an intriguing Norwegian study. Researchers followed more than 77,000 people for a median of 33.5 years in a population where potatoes were predominantly eaten boiled. Those eating at least 14 potatoes per week had a 12 percent lower risk of all-cause mortality than those eating six or fewer, and each additional 100 grams per day was associated with about a 4 percent reduction in all-cause and cardiovascular mortality.
And perhaps the most interesting historical example comes from Okinawa. The traditional Okinawan diet, associated with extraordinary longevity, was not low carbohydrate at all. It was historically very high in carbohydrate, with the sweet potato serving as its dominant caloric staple alongside green vegetables, soy foods and relatively small amounts of animal food.
Preparation matters. A boiled sweet potato and a carton of French fries are both technically potatoes in roughly the same way that grapes and grape soda are both fruit products.
Beans May Be the Most Underrated Food on Earth
Beans may be the least glamorous superfood on Earth. Nobody puts a velvet rope outside a lentil restaurant.
Yet legumes – lentils, chickpeas, black beans, kidney beans and peas – combine protein, slowly digested carbohydrate, soluble and insoluble fiber, resistant starch, potassium, magnesium, folate and polyphenols in one inexpensive package.
They generally produce smaller glucose excursions than refined carbohydrates, and their soluble fiber can help lower LDL cholesterol. More importantly, they deliver enormous quantities of substrate to the intestinal microbiome.
A systematic review and dose-response meta-analysis involving 32 cohorts, more than 1.1 million participants and over 93,000 deaths found that higher legume consumption was associated with lower all-cause mortality. Each additional 50 grams per day was associated with approximately a 6 percent reduction in mortality.
The effect is not enormous. But consider what we are discussing. Beans. No prescription. No patent. No refrigerated biologic medication. Just beans.
The Common Thread Is Not Carbohydrate
Notice something else. These categories contain substantial carbohydrate. Yet they repeatedly appear in dietary patterns associated with longevity.
This is where the argument that “carbohydrates are bad” runs into trouble. Human physiology does not eat macronutrient percentages. Humans eat food.
A bowl of steel-cut oats and a glazed doughnut both contain carbohydrate in roughly the same sense that a violin and a park bench both contain wood.
What distinguishes these traditional plant foods is their food matrix – fiber, intact cellular structures, minerals, phytochemicals, resistant starch and slowly digestible carbohydrate arriving together.
And perhaps most importantly, they feed something besides us. They feed our microbes.
We Have Been Forgetting to Feed an Organ
The colon contains an extraordinary microbial ecosystem that our ancestors unknowingly fed every day.
Fiber and resistant starch travel into that ecosystem and are fermented into short-chain fatty acids including acetate, propionate and butyrate. These compounds participate in intestinal barrier function, immune regulation, glucose metabolism and inflammatory signaling.
A systematic review of human intervention trials confirms that dietary fibers can alter both gut microbial composition and short-chain-fatty-acid production, although the response varies substantially according to the type of fiber and the individual microbiome. Reviews of the broader mechanistic literature similarly describe dietary fiber as one of the major determinants of microbial ecology and production of metabolites such as butyrate.
Modern humans often feed themselves generously while starving their microbes. Ultra-processed food is exceptionally easy for the upper gastrointestinal tract to absorb. By the time it reaches the colon, the buffet may be largely over.
Beans, whole grains, vegetables and resistant starch bring dinner downstairs.
The Pattern Matters More Than the Superfood
The most important lesson may therefore be the least exciting one. There probably isn’t a longevity food. There is a longevity pattern.
Across Mediterranean diets, traditional Okinawan diets and other healthy dietary patterns, remarkably similar characters keep wandering onto the stage – vegetables, whole grains, legumes, tubers, fruit and other minimally processed plant foods. The proportions vary enormously. The foods vary. Even the macronutrient composition varies. The theme does not.
None of this is to say that everyone should become vegetarian. Fish, eggs, fermented dairy and thoughtfully consumed meat can certainly fit into a healthy diet.
But plants should probably stop being the parsley decorating the steak. They belong in the center of the conversation.
Grains, greens, tubers and beans are inexpensive, ancient and spectacularly unmarketable. Nobody owns the patent on a lentil. There is no monthly subscription required to obtain a sweet potato.
Perhaps that is why they seem so ordinary. But the biology underneath them is anything but ordinary.
Grains from the field. Greens from the garden. Tubers from beneath the soil. Beans from the vine. Nothing terribly exotic. Just four old foods that seem to play a role in keeping humans alive longer.
Author
Scott Rollins, MD, is Board Certified with the American Board of Family Practice and the American Board of Anti-Aging and Regenerative Medicine. He specializes in bioidentical hormone replacement for men and women, thyroid and adrenal disorders, fibromyalgia and other complex medical conditions. He is founder and medical director of the Integrative Medicine Center of Western Colorado (www.imcwc.com) and Bellezza Laser Aesthetics (www.bellezzalaser.com). Call (970) 245-6911 for an appointment or more information.
