Should we give up carbohydrates after 40?

We shouldn't give up on carbohydrates , even when we turn 40 and enter middle age. But we should choose wisely which ones we include in our diet . A new study from the USDA's Jean Mayer Human Nutrition Research Center on Aging (HNRCA) at Tufts University and the Harvard T.H. Chan School of Public Health states that consuming dietary fiber and high-quality carbohydrates at this stage of life is favorably associated with healthy aging and other positive health outcomes. The results are published in the journal JAMA Network Open.

"We've all heard that different carbohydrates can affect health differently, whether in terms of weight, energy, or blood sugar levels. But rather than just looking at the immediate effects of these macronutrients, we wanted to understand what they might mean for good health 30 years later. Our findings suggest that carbohydrate quality may be an important factor for healthy aging," says Andres Ardisson Korat, a scientist at the HNRCA and senior author of the study.

Researchers analyzed data from the Nurses' Health Study questionnaires, collected every four years between 1984 and 2016, to examine the midlife diets and eventual health outcomes of more than 47,000 women who were between 70 and 93 years old in 2016.

Researchers defined healthy aging as the absence of 11 major chronic diseases, lack of decline in cognitive and physical function, and good mental health, as self-reported by participants in the Nurses' Health Study questionnaires. In the new study, 3,706 participants met the definition of healthy aging.

The analysis showed that consumption of total carbohydrates, high-quality carbohydrates from whole grains, fruits, vegetables, and legumes , and total dietary fiber in midlife was associated with a 6% to 37% increase in the likelihood of healthy aging and several positive aspects of mental and physical health. On the other hand, consumption of refined carbohydrates (from added sugars, refined grains, and potatoes) and starchy vegetables was associated with a 13% decrease in the likelihood of healthy aging.

"Our results are consistent with other evidence linking consumption of fruits and vegetables, whole grains, and legumes with lower risks of chronic diseases , and we now see the association with physical and cognitive function outcomes," said senior author Qi Sun, an associate professor in the departments of nutrition and epidemiology at Harvard Chan School.

The authors point out as a limitation that the study population was composed primarily of white healthcare professionals. Future research will be needed to replicate these findings in more diverse cohorts.

Ardisson Korat also believes that more research is needed to understand the potential mechanisms linking dietary fiber and high-quality carbohydrates to healthy aging. "Studies are beginning to find an association between dietary choices in midlife and quality of life in later life . The more we understand about healthy aging, the more science can help people live healthier and longer," Ardisson Korat concludes.