Women who ate more fiber-rich carbohydrates at age 40 were more likely to reach 70 without serious illness or loss of autonomy, according to a 2025 study that followed more than 47,000 women for over three decades. The findings, published in JAMA Network Open, add fresh weight to the idea that not all carbohydrates age the body the same way.
Researchers from the Harvard T.H. Chan School of Public Health and the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University tracked 47,513 women in the Nurses’ Health Study and found that higher intake of quality carbohydrates and dietary fiber was linked to a 6 to 37 percent greater chance of healthy aging. In this study, healthy aging meant living past 70 without 11 major chronic diseases, major limits in memory or mobility, or poor mental health. Andres Ardisson Korat and Qi Sun were among the authors.
The numbers were stark. Only 7.8 percent of the women reached healthy aging. Replacing 5 percent of calories from refined carbohydrates with high-quality carbohydrates lifted the odds by about 8 to 16 percent, while a 10 percent increase in energy from refined carbohydrates was associated with about a 13 percent drop in the chances of aging well. High-quality carbohydrates were defined as whole grains, fruits, nonstarchy vegetables and legumes.
The pattern held across several measures. A higher glycemic index and an unfavorable carbohydrate-to-fiber ratio were tied to lower chances of maintaining good form, and large amounts of potatoes or corn also reduced the share of women who aged well. The study’s authors said the message after 40 is not to fear every carb, but to swap sugary products and white flour for fiber-rich foods and work gradually toward 25 to 30 grams of fiber a day.
That matters because many women cut back on pasta or bread after 40 on the belief that all carbohydrates work against weight and health. The research suggests the issue is quality, not just quantity. Still, the study was observational, so it cannot prove that the carbs caused the healthier aging it recorded, and the participants were American nurses who were mostly white and educated.
Even so, the takeaway is clear enough for ordinary meals: a miser approach to carbohydrates may be the wrong one if it means trimming away the foods most likely to protect health over time. The question now is less whether carbohydrates belong on the plate than which ones should take the place of refined grains.
