In collaboration with the Harvard T.H. Chan School of Public Health, a recent study conducted by researchers at the Jean Mayer USDA Human Nutrition Research Center on Aging (HNRCA) at Tufts University has shed new light on the long-term benefits of consuming high-quality carbohydrates during midlife. Published on 16 May in JAMA Network Open, the research highlights the pivotal role of dietary fibre and unrefined carbohydrates in promoting healthy ageing and positive health outcomes in later life, particularly among older women. The findings add a significant layer to our understanding of how midlife nutrition shapes immediate health and long-term well-being as we grow older.
According to Andres Ardisson Korat, a scientist at the HNRCA and lead author of the study, while we have long known that different carbohydrates have varying effects on health, this research moves beyond short-term considerations. “We have all heard that different types of carbohydrates can influence health in multiple ways, whether it is weight control, energy levels, or blood sugar regulation,” he explained. “However, instead of focusing merely on these immediate outcomes, we wanted to explore how carbohydrate quality might affect overall health some 30 years later.” This perspective shifts the conversation towards a more holistic view of dietary choices made in our middle years and their substantial implications for ageing well.
The research team drew upon data from the long-running Nurses’ Health Study, which involved periodic dietary questionnaires completed every four years from 1984 to 2016. This rich dataset allowed the researchers to assess the midlife dietary habits and eventual health outcomes of more than 47,000 women, who by 2016 were aged between 70 and 93 years. The data covered a comprehensive range of carbohydrate sources, including total carbohydrates, refined carbohydrates, high-quality (unrefined) carbohydrates, whole grains, fruits, vegetables, legumes, dietary fibre, and dietary glycaemic index and load. The researchers defined healthy ageing in a multifaceted way: the absence of eleven major chronic diseases, no cognitive or physical functional decline, and good mental health, all self-reported by the study’s participants.
What emerged from this analysis was compelling. The study found that higher intakes of total carbohydrates and, more specifically, high-quality carbohydrates derived from whole grains, fruits, vegetables, and legumes, as well as greater consumption of dietary fibre, were linked to a 6 to 37% increased likelihood of healthy ageing. Notably, these nutritional habits were also associated with better physical and mental health outcomes, extending beyond the traditional focus on disease risk reduction. In contrast, consuming refined carbohydrates from added sugars, refined grains, and starchy vegetables, including potatoes, was associated with a 13% decrease in the odds of experiencing healthy ageing. This underscores that not all carbohydrates are created equal and that dietary quality can be as important as quantity.
Qi Sun, senior author of the study and associate professor in the departments of nutrition and epidemiology at Harvard Chan School, emphasised that these findings support existing evidence linking plant-based, high-fibre diets to lower risks of chronic diseases. However, the new research adds further nuance by linking these dietary patterns to enhanced physical and cognitive function in later life. “Our results are consistent with previous studies that highlight the importance of fruits, vegetables, whole grains, and legumes in reducing chronic disease risks. What is new here is the association with physical and cognitive health, which is a critical part of what makes for healthy ageing,” Sun noted.
Nevertheless, the authors acknowledged certain limitations. Because the study cohort was composed mainly of white health professionals, there is a need to replicate these findings across more diverse populations to ensure the results are broadly applicable. Ardisson Korat also noted the need for further research to uncover the underlying biological mechanisms through which dietary fibre and high-quality carbohydrates contribute to these positive ageing outcomes. He concluded, “There is growing evidence that our food choices in midlife can shape the quality of life we experience in later years. The better we understand the science of healthy ageing, the more effectively we can guide people to make choices that support living healthier and more fulfilling lives as they age.” This research adds to a growing body of work highlighting that diet in midlife is not just about staving off disease but about laying a foundation for a robust, vibrant old age.
More information: Andres Ardisson Korat et al, Dietary Carbohydrate Intake, Carbohydrate Quality, and Healthy Aging in Women, JAMA Network Open. DOI: 10.1001/jamanetworkopen.2025.11056
Journal information: JAMA Network Open Provided by Tufts University
