Effect of whole grains on markers of subclinical inflammation.

The reduction of subclinical inflammation has been suggested as a potential mechanism to explain the favorable association between whole-grain consumption and reduced risk for cardiovascular disease, diabetes, and certain cancers. This review examines evidence for the effects of whole-grain consumption on markers of subclinical inflammation derived from 13 epidemiological and 5 interventional studies retrieved from a search of the PubMed database. Epidemiological studies provide reasonable support for an association between diets high in whole grains and lower C-reactive protein (CRP) concentrations. After adjusting for other dietary factors, each serving of whole grains is estimated to reduce CRP concentrations by approximately 7%. In contrast to epidemiological studies, interventional studies do not demonstrate a clear effect of increased whole-grain consumption on CRP or other markers of inflammation. Issues related to insufficient length of intervention, extent of dietary control, population selection, types of whole grains, and lack of a direct anti-inflammatory effect may underlie these discrepant findings. Additional carefully controlled interventional studies are needed to clarify the effects of whole grains on subclinical inflammation.