Background

Whole grain foods encompass a range of products and include whole grain wheat, rice, maize, and oats. The term 'whole grain' also includes milled whole grains such as oatmeal and wholemeal wheat.

Study characteristics

We evaluated nine randomised studies assessing the effects of whole grain diets compared to diets with refined grains or a usual diet on levels of cholesterol in the blood or blood pressure (major risk factors for cardiovascular disease including heart attacks or stroke). The evidence is current to August 2016.

Key results

The diets were followed for at least 12 weeks, but most studies had some methodological limitations, numbers of participants were small, and the overall quality of the evidence was low. We found no studies reporting on the effect of whole grains on deaths from cardiovascular disease or cardiovascular events. All nine included studies reported the effects of whole grain diets on levels of cholesterol in the blood or blood pressure. We found no effects on blood cholesterol or blood pressure in favour of whole grain diets. Four studies were funded by independent national and government funding bodies, while the remaining studies reported funding or partial funding by organisations with commercial interests in cereals.

Conclusion