Whole grains form a part of many diets deemed to be beneficial for health - such as the Mediterranean diet. But what health benefits do whole grains offer in their own right? According to a new study, eating more of them may reduce mortality, particularly deaths resulting from cardiovascular disease.
Grains are made up of three parts: the bran layers, germ and endosperm. Refined grains often have the bran layers and germ removed, while whole grains contain all three elements. Foods that contain whole grains include whole-wheat flour, oatmeal, cornmeal, bulgur and brown rice.
In general, whole grains are thought to be better for health than refined grains. As part of a healthy diet, whole grains have been associated with reduced blood cholesterol and improved weight maintenance.
"Compared with refined carbohydrates, whole grains contain many beneficial nutrients and phytochemicals that primarily reside in the outer layers of grains that are removed during milling processes to produce refined grain products," explain the researchers, including Hongyu Wu, PhD, of the Harvard School of Public Health in Boston, MA.
However, the team says data from studies investigating the association between whole grain intake and overall health have been "inconsistent." As such, they set out to assess the effect of whole grain intake on risk of death.
To reach their findings - published in JAMA Internal Medicine - Wu and colleagues analyzed data from two large studies: the Nurses' Health Study, from which 74,341 women were assessed between 1984 and 2010, and the Health Professionals Follow-Up Study, from which 43,744 men were analyzed between 1986 and 2010.
The results of the analysis revealed that a higher intake of whole grains was associated with reduced risk of overall mortality and lower risk of CVD mortality; each serving of whole grains (28 g) was linked to a 5% reduced total mortality risk or a 9% lower risk of CVD mortality.