White bread lovers, beware: An analysis of two large studies suggests that those who opt to eat whole grains live longer and are less likely to die of heart disease.

Reuters reports the findings come after earlier research had also linked whole grains to a decreased risk of type 2 diabetes.

At least in the United States, consumers have little reason to feign ignorance.

"Reading the ingredients of food labels, consumers will know whether the food contains any whole grain contents," Qi Sun, the report's senior author, said.

Common types of whole grains include whole wheat flour, brown rice, whole oats, whole cornmeal and even popcorn, said Sun, a member of the Harvard School of Public Health's nutrition department.

Eating more whole grains may lower people's risk of death by up to 15 percent, the Los Angeles Times reported based on the professor's findings. The benefit is likely linked to bran, the fibrous coating that processing removes from whole wheat and brown rice.

The analysis found that increased bran intake resulted in up to 6 percent lower overall death risk and decreased the risk for cardiovascular disease by up to 20 percent.

"This study further endorses the current dietary guidelines that promote whole grains as one of the major healthful foods for prevention of major chronic diseases," Sun said.

The U.S. Department of Agriculture recommends at least half the grains consumed each day should come from whole grains, the professor told Reuters.

Whole grains contain a number of beneficial nutrients, among them fiber, magnesium, vitamin E and plant-based compounds called phytochemicals. Grains such as whole wheat, brown rice, whole oats, barley and farro help the body regulate blood sugar, fat and cholesterol; maintain blood vessel health; help prevent DNA damage; and reduce inflammation.

Sun's findings, reported in the JAMA Internal Medicine journal, resulted from further analysis of women studied between 1984 and 2010 in the so-called Nurses' Health Study, as well as men observed between 1986 and 2010 in what is known as the Health Professionals Follow-Up Study. Health records and dietary questionnaires in both surveys were updated periodically.