Women who ate the most high-quality carbohydrates and dietary fiber in their 40s and 50s had 6 to 37 percent greater odds of reaching older age free of major chronic disease, memory problems, physical limits, and poor mental health, according to a 30-year study of 47,513 women published in JAMA Network Open in May 2025.
The finding is drawn from the long-running Nurses' Health Study and was led by researchers at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University with the Harvard T.H. Chan School of Public Health.
Diet was tracked with food questionnaires every four years between 1984 and 2016, when the women were 70 to 93 years old.
Only 3,706 of the participants, about 7.8 percent, met the study's strict definition of healthy aging, which required surviving to at least age 70 without any of 11 major chronic diseases, without memory or physical impairment, and with good mental health.
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Where the biggest gains showed up
The odds of healthy aging rose most sharply with vegetables, fruit (not juice), whole grains, and legumes. Every 5 percent of daily calories from vegetables was tied to 37 percent higher odds of healthy aging, from fruit to 22 percent higher odds, and from whole grains to 11 percent higher odds, the study reported.
Refined carbohydrates, starchy vegetables, and higher-glycemic diets moved the numbers in the opposite direction.
"Our findings suggest that carbohydrate quality may be an important factor in healthy aging," said Andres Ardisson Korat, a scientist at the Jean Mayer USDA Human Nutrition Research Center on Aging and the study's lead author, in a statement released with the paper.
The results echo what nutrition research has shown for years about chronic disease risk, added senior author Qi Sun, associate professor at the Harvard Chan School. "Now we see the association with physical and cognitive function outcomes," he told Tufts Now.
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Because the study is observational, it can show a strong link but not prove that fiber itself causes the difference. The authors also note the cohort was made up mostly of white health professionals, and the results need to be replicated in more diverse groups.
Seven everyday foods that help you hit the target
Most US adults fall well short of the 25 to 35 grams of fiber a day that Harvard's nutrition experts describe as adequate for good health, averaging closer to 15 grams.
The food groups the study flagged as protective are also the easiest way to close that gap.
Food Also read: What pomegranate juice does to your blood pressure if you drink it every day | Typical serving | Approx. fiber |
|---|---|---|
Cooked lentils | 1 cup Also read: Reboiling water twice: Here is what actually happens in your kettle | ~15 g |
Chickpeas (cooked) | 1 cup | ~12-13 g Also read: Your daily vitamin routine may not be protecting you the way you think it is |
Rolled oats (dry) | 1/2 cup | ~4 g |
Raspberries | 1 cup | ~8 g |
Broccoli (cooked) | 1 cup | ~5 g |
Apple with skin | 1 medium | ~4 g |
Whole-grain bread | 1 slice | ~2-4 g |
A bowl of oatmeal with berries, a lentil or chickpea soup at lunch, and broccoli with dinner can put a woman in her 40s or 50s close to the daily target without any drastic overhaul.
That is the same kind of pattern other long-term work has linked to healthier aging, including a large study that found daily nut eaters had better healthy-aging outcomes.
Why the midlife window matters
What sets this study apart is timing. It captured what women were eating decades before their health outcomes were measured, which is why researchers keep returning to midlife as the period when diet appears to shape later life most strongly.
Similar research has connected small daily habits, including diet quality, to several extra healthy years.
None of this points to a single magic food. Ardisson Korat framed the takeaway modestly, telling Tufts that "science can help people live healthier for longer."
The practical version is simpler still. The plate you build in your 40s and 50s may be quietly setting up the health you carry into your 70s.
This article is made and published by Jesper Bengtson, who may have used AI in the preparation.