New Study Finds Carbohydrates and Fiber Associated with Healthier Aging in Certain Populations
Tufts University study reveals that fiber and high-quality carbs boost wellness and lower disease risk in older women.
Carbohydrates have long been maligned in popular diet culture, but a newly published study suggests that not all carbs are created equal—especially when it comes to the long-term health of older women. Researchers from Tufts University and Harvard T.H. Chan School of Public Health have discovered that regularly consuming fiber and high-quality carbohydrates during midlife is closely linked to healthier aging, as well as improved physical and mental wellbeing for women as they enter their later years.
The comprehensive study evaluated what it means to age healthily, defining it as the absence of 11 major chronic diseases, maintaining strong cognitive and physical function, and enjoying good mental health. Data was collected from over 47,000 participants in the Nurses’ Health Study, spanning more than three decades and monitoring women as they aged from their 70s into their 90s. The team specifically analyzed dietary intake, looking at the types and sources of carbohydrates—whether they came from whole grains, fruits, vegetables, or legumes—and their impact on aging outcomes.
According to lead researcher Andres Ardisson Korat, the key message is clear: “Consuming dietary fiber and high-quality carbohydrates—those found in unrefined plant foods—is associated with positive health status in older adulthood.” The findings revealed that higher consumption of these nutrient-dense, fiber-rich foods corresponded to a markedly higher likelihood—ranging from 6% to 37%—of healthy aging. Conversely, diets high in refined carbohydrates such as added sugars, white bread, and starchy vegetables like potatoes were linked to a 13% reduction in the odds of aging healthfully.
Of particular note, the study spotlighted that replacing just 5% of calories from carbohydrates with protein actually decreased the chance of healthy aging by up to 37%, regardless of whether the protein was sourced from plants or animals. This counters some prevalent assumptions about high-protein diets being universally beneficial for longevity. Additionally, the research found that the benefits of high-quality carbs were independent of body weight, emphasizing that it’s the source and quality of carbohydrates—not just calorie count or weight loss—that contributes to optimal health as women age.
The researchers also delved into the contentious topic of dietary fats, finding that greater intake of polyunsaturated fatty acids (PUFAs), often found in seed oils, was associated with lower odds of healthy aging. This adds a new dimension to the ongoing debate about the role of different fats in the diet.
Based on these insights, nutrition experts recommend focusing on whole and unprocessed foods—prioritizing fruits, vegetables, whole grains, and legumes. Simple changes, such as shopping the perimeter of the grocery store for fresh produce and whole grains, and choosing frozen options when fresh isn't available, can make a meaningful difference. For those who can tolerate grains, foods like quinoa, brown rice, oats, and whole wheat products are particularly beneficial. Limiting refined carbohydrates—including white bread, sugary drinks, and ultraprocessed snacks—can also support healthy aging and reduce the risk of chronic diseases.
Despite its strengths, the study has some limitations: the population studied consisted mainly of white female healthcare workers, making it unclear how applicable the results might be to men or more diverse groups. The researchers acknowledge the need for broader studies to fully understand the relationship between fiber, carbohydrate quality, and healthy aging across different populations.
The overarching takeaway is that diet quality truly matters. Beyond macronutrient ratios, the types of carbohydrates consumed play a crucial role in promoting health and longevity. While diet remains foundational in the pursuit of healthy aging, experts emphasize that it must be combined with regular exercise, adequate sleep, effective stress management, and robust social connections to achieve the best outcomes. Personalized nutrition, grounded in scientific evidence and tailored to individual needs, may ultimately hold the key to thriving well into old age.
