“We wanted to test whether following a healthy diet could lower a person’s biological age,” Kresovich explained. (Photo courtesy of Steve McCaw / NIEHS)

NIEHS researchers have found that a healthy diet is associated with lowering a woman’s biological age, which refers to how old she is on a cellular level (see first sidebar). Published Oct. 12 in the American Journal of Clinical Nutrition, the study provides additional evidence that good nutritional choices can lead to positive health effects.

Eating patterns and measures of biological age

Previous studies that examined the relationship between diet and biological age primarily focused on individual food items, such as fruits, red meat, or fish.

“A person’s diet is more complex than that,” said co-first author Jacob Kresovich, Ph.D., an Intramural Research Training Award postdoctoral fellow in the NIEHS Molecular and Genetic Epidemiology Group, which is led by Jack Taylor, M.D., Ph.D. “Therefore, we wanted to determine whether dietary patterns, which are more integrated measures of an individual’s diet, are associated with a person’s biological age.”

The present study found that a balanced, high-quality diet — one rich in fruits, vegetables, and whole grains and low in red meat, added sugars, and saturated fats — appears to slow the effects of aging in women. Results were especially strong for measurements of biological age designed to predict an individual’s mortality risk.

“We also discovered that the beneficial effects of eating a healthy diet were more robust among women who did not meet CDC [Centers for Disease Control and Prevention] guidelines for exercise,” noted Taylor, the co-senior author. “This suggests that improving diet quality may be particularly useful for those with lower levels of physical activity.”

“With this research, we found another piece of evidence that eating healthy food has beneficial biological effects,” Taylor noted. (Photo courtesy of Steve McCaw / NIEHS)

Data from Sister Study

Researchers analyzed data from the NIEHS Sister Study, which examines risk factors for breast cancer in 50,884 women between the ages of 35 and 74 years and who had a sister with breast cancer. The women are from across the U.S. and Puerto Rico.

Participants answered questions about their food consumption in the past 12 months, and their responses were used to calculate adherence to different healthy eating indexes. Dietary patterns investigated in this research included one protective against hypertension (Dietary Approaches to Stop Hypertension, often called the DASH diet), the Mediterranean diet, and two versions of the Healthy Eating Index. Developed by the U.S. Department of Agriculture Food and Nutrition Service, the Healthy Eating Index is a measure of overall diet quality based on recommendations in the Dietary Guidelines for Americans (see second sidebar).

The women also provided blood samples, which were analyzed for DNA methylation, a naturally occurring chemical modification to DNA that can regulate gene expression. Methylation signatures across the genome can be used to predict biological age and mortality, according to the researchers.

A novel component and future work

According to the authors, one particularly unique aspect of this study was the ability to investigate four different healthy eating patterns. Each pattern showed a reduction in age acceleration, indicating that no pattern was more beneficial than another.

“As opposed to individual food items, dietary patterns may provide a better representation of what people eat,” Sandler said. (Photo courtesy of Steve McCaw / NIEHS)

“Instead, we found that eating a balanced diet that includes plenty of fruits and vegetables and lower amounts of sodium and red meat was associated with lower biological age and a slower rate of aging,” noted co-senior author Dale Sandler, Ph.D., chief of the NIEHS Epidemiology Branch.

In future studies, the researchers plan to analyze how dietary patterns that increase oxidative stress and inflammation may influence biological aging.

Citation: Kresovich JK, Park YM, Keller JA, Sandler DP, Taylor JA. 2021. Healthy eating patterns and epigenetic measures of biological age. Am J Clin Nutr; doi:10.1093/ajcn/nqab307 [Online 12 Oct 2021].

(Tara Ann Cartwright, Ph.D., is a technical writer-editor in the NIEHS Office of Communications and Public Liaison.)