Whole grain intake is associated with lower risk of cardiovascular disease and lower mortality rate in patients with type 2 diabetes, Harvard School of Public Health researchers say.

The study, published in The American Heart Association’s Circulation journal on monday, analyzed data from 7,822 U.S. female nurses with type 2 diabetes and found that the group of individuals with the highest level of grain intake displayed a 16 to 31 percent lower mortality rate than the group at the lowest level.

In addition, the researchers found that women with type 2 diabetes who consumed bran—the fiber-filled part of the whole grain—displayed lower mortality rates due to cardiovascular disease.

Though other studies have examined relationships between whole grain intake and mortality, this paper is the first to look at data compiled on individuals who already have diabetes, according to Lu Qi, an assistant professor in the department of nutrition at HSPH who co-authored the study.

Because his team examined a pool of nurses who have obtained a higher education than the general population, the findings provided more accurate and reliable information, Qi said.

The study is unique because it analyzed data for people who already have diabetes, unlike previous research that draws associations between whole grain consumption and mortality rates in healthy people, according to Eric L. Ding, an HSPH research fellow, who is unaffiliated with the study.

“The study shows that even if you have already developed disease, it’s never too late to prevent more mortality risk in the future,” Ding said.

—Staff writer Xi Yu can be reached at xyu@college.harvard.edu.