The Healthiest Carbs for Healthy Aging, According to a 30-Year Study

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The Healthiest Carbs for Healthy Aging, According to a 30-Year Study

New research following more than 47,000 women suggests that the quality of the carbohydrates you eat in midlife may help shape how well you age.

Carbohydrates have spent decades being cast as the nutritional villain. Bread gets blamed for weight gain. Pasta gets swapped for protein. Potatoes disappear from dinner plates. And “cut the carbs” has become shorthand for eating healthier.

But carbohydrates aren't one thing. A long-running study offers a useful reminder that where your carbs come from may matter far more than simply eating fewer of them.

TL;DR

Carb quality — not carb quantity — tracked with healthy aging across three decades. Whole grains, fruit, vegetables and legumes were associated with better outcomes; refined grains and added sugars with worse ones. Fiber may explain much of the effect.

✥Every 10% of calories from high-quality carbs: 31% higher odds of healthy aging.

✥The same increase in refined carbs: 13% lower odds.

✥Only 7.8% of the 47,513 women met every criterion for healthy aging.

✥Observational study — associations, not proof of cause.

The study

Chapter 01 · JAMA Network Open, 2025

In a 2025 study published in JAMA Network Open, researchers examined the diets of 47,513 women in the Nurses' Health Study and followed their health for more than three decades. They wanted to know whether the kinds of carbohydrates women ate in midlife were associated with how healthy they were in their 70s, 80s, and early 90s.

The finding was striking: women who consumed more high-quality carbohydrates from whole grains, fruits, vegetables, and legumes had greater odds of what researchers called healthy aging — and healthy aging meant considerably more than simply living longer. Researchers looked for women who reached older adulthood without 11 major chronic diseases, physical limitations, memory problems, or poor mental health.

The women were an average of about 48 years old when researchers began assessing their diets in the mid-1980s. Their health was evaluated decades later, when participants were between 70 and 93.

Keep in mind: the study was observational, which means it can identify associations but cannot prove that eating a particular kind of carbohydrate caused someone to age better. And a 31% increase in odds does not mean someone becomes 31% healthier.

Still, the larger pattern was consistent. Carbohydrates from fruits, vegetables, whole grains, and legumes were associated with better aging outcomes. Dietary fiber was, too. Diets with a higher glycemic index and a higher ratio of carbohydrate to fiber were associated with poorer outcomes.

Carbohydrates aren't automatically healthy or unhealthy. Their source matters.

What Makes a Carb “High Quality”?

Chapter 02 · The package, not the macro

Picture two breakfasts. One is a bowl of oatmeal topped with berries and walnuts. The other is a frosted pastry. Both contain carbohydrates — your body can break both down into glucose. But nutritionally, they're very different packages.

Whole carbohydrate foods tend to arrive with other things your body can use: fiber, vitamins, minerals, plant compounds, and intact food structures that influence how quickly they're digested. Highly refined carbohydrates have often had much of that structure — and particularly fiber — removed during processing.

In this study, researchers classified carbohydrates from whole grains, fruits, non-starchy vegetables, and legumes as high quality. Refined grains and added sugars were among the lower-quality sources they examined.

The Carb Quality Test

When choosing a carbohydrate, ask what comes with it.

More often

Whole grains

Whole fruit

Vegetables

Beans and lentils

Fiber

Less often

Refined grains

Foods high in added sugars

Highly processed starches

Low-fiber packaged foods

Little or no fiber

The idea: don't judge a food simply because it contains carbohydrates. Look at the entire nutritional package.

Fiber May Be the Quiet Star

Chapter 03 · One nutrient kept reappearing

One nutrient kept showing up throughout the research: fiber. Women who consumed more total dietary fiber in midlife had greater odds of healthy aging decades later. Fiber from fruits, vegetables, and cereal grains was also associated with better outcomes.

When researchers statistically accounted for fiber, some of the associations between carbohydrate intake and healthy aging became weaker. That suggests fiber may explain at least part of the relationship — and it would make biological sense.

Fiber does much more than keep digestion regular. Certain types can slow digestion and moderate the rise in blood sugar after eating. Soluble fiber can help lower LDL cholesterol. Other fibers reach the colon, where gut microbes ferment them and produce compounds that help support the intestinal environment. And unlike many headline-grabbing nutrients, fiber is abundant in remarkably ordinary foods.

The Fiber Upgrade

You don't need an exotic superfood. Start here.

Beans + lentils

Fiber, plant protein, and resistant starch in one inexpensive package.

Oats + barley

Whole grains rich in soluble fiber.

Berries + apples + pears

Whole fruit delivers fiber alongside its naturally occurring sugars.

Vegetables

Enormous variety, different vitamins and plant compounds in each.

Nuts + seeds

Fiber plus unsaturated fats, protein, and minerals.

Whole grains

More of the original grain means more of its fiber and nutrients.

5 Carbohydrate Sources Worth Eating More Often

What About Glycemic Index?

Chapter 05 · A number with limits

You've probably encountered the term glycemic index, or GI. It describes how quickly carbohydrate-containing foods raise blood glucose compared with a reference food. In this study, diets with a higher overall glycemic index were associated with lower odds of healthy aging, and a higher carbohydrate-to-fiber ratio with poorer outcomes.

But that doesn't mean you need to memorize the glycemic index of everything in your pantry. Meals are complicated. We rarely eat one carbohydrate in isolation, and protein, fat, fiber, preparation method, portion size, and the other foods on your plate can all influence the blood-sugar response.

Chapter 04 · Where to start

The study wasn't designed to crown individual foods as longevity champions. Instead, it identified broader carbohydrate categories associated with healthier aging. Within those categories, these are useful places to start.

01

Whole Grains

Oats, barley, quinoa, brown rice, farro, whole-wheat bread, and even popcorn all qualify. Whole grains retain more of the original grain — including fiber-rich components often removed during refining. In the study, greater carbohydrate intake from whole grains was associated with higher odds of healthy aging.

When shopping for bread or cereal, look beyond the color of the package or words like “multigrain.” Checking whether a whole grain appears near the beginning of the ingredient list can tell you more.

02

Whole Fruit

Apples, oranges, berries, pears, and peaches provide carbohydrates alongside fiber, water, vitamins, and plant compounds. Importantly, the researchers classified carbohydrates from whole fruit — not fruit juice — as high quality.

Eating an orange means consuming its fiber and intact structure along with its naturally occurring sugars. Juice removes much of that structure. You don't need to fear the sugar in an apple; the package matters.

03

Vegetables

In the study, carbohydrates from non-starchy vegetables were positively associated with healthy aging. Think leafy greens, broccoli, peppers, carrots, tomatoes, and cauliflower.

There is no need to identify one perfect vegetable. Variety — and finding vegetables you genuinely enjoy enough to eat regularly — matters more.

04

Beans and Lentils

Beans, chickpeas, peas, and lentils are nutritional multitaskers: carbohydrates, fiber, plant protein, minerals, and resistant starch in the same food. They're also inexpensive, shelf-stable, and easy to add to soups, salads, grain bowls, tacos, stews, and pasta dishes.

05

Fiber-Rich Foods in General

Perhaps the clearest lesson isn't about any particular food at all. Rather than obsessing over whether a food technically contains carbohydrates, looking at what comes with those carbohydrates — including fiber — can tell you much more about its nutritional quality.

What About Glycemic Index?

Chapter 05 · A number with limits

You've probably encountered the term glycemic index, or GI. It describes how quickly carbohydrate-containing foods raise blood glucose compared with a reference food. In this study, diets with a higher overall glycemic index were associated with lower odds of healthy aging, and a higher carbohydrate-to-fiber ratio with poorer outcomes.

But that doesn't mean you need to memorize the glycemic index of everything in your pantry. Meals are complicated. We rarely eat one carbohydrate in isolation, and protein, fat, fiber, preparation method, portion size, and the other foods on your plate can all influence the blood-sugar response.