Evidence for a Whole Grains and Coronary Heart Disease Health Claim

Abstract

A systematic review was undertaken to evaluate the evidence for a health claim about whole grain (WG) products and coronary heart disease (CHD). Studies were excluded if the American Association of Cereal Chemists International WG definition was not met or if foods with less than 51% WG ingredients were classified as WG. Seventeen of 26 clinical trials reported sufficient information to be included in the meta- analysis. Overall, pooled analyses suggested that WG products have total and LDL cholesterol-lowering effects. No effect remained when trials that tested single grains high in β-glucan fibre, such as oats, and poor quality studies were removed from the analysis. The cohort studies were too heterogeneous to calculate pooled risk estimates. Four of 6 cohort studies reported at least one improved CHD outcome in individuals who consumed more WG products. Two of the positive studies were poor quality; the remaining 2 were separate analyses of the same cohort. Health Canada concluded that the evidence to date was not sufficient to support a health claim about WG products in general and CHD. The effect of β-glucan fibre cannot be generalized to other grains, including wheat, the main grain consumed in Canada. Health Canada has already accepted health claims about oat and barley products and cholesterol-lowering.