Eating whole grains suppresses inflammation

Higher consumption of whole grains is associated with lower serum levels of high-sensitivity C-reactive protein (hs-CRP), a recent study has found. Conversely, intake of refined grains raises the concentration of hs-CRP.

A total of 756 generally healthy adults (aged 53–73 years) participated in the study. Four-day food records were used to monitor and assess dietary quality. Overall, men ate an average of 164 g/day of whole grains, while women consumed 106 g/day. The corresponding intakes for refined grains were 92 and 75 g/day. Mean serum hs-CRP levels were 1.77 and 1.96 mg/L in men and women, respectively.

The baseline analysis of covariance model revealed that mean serum hs-CRP levels decreased significantly with increasing quartiles of whole grain intake (Q4 vs Q1: 1.53 vs 2.39 mg/L; p_trend=0.001). Linear regression analysis showed that taking whole grain intake as a continuous variable had the same effect, such that each 50-g/day increase in consumption correlated with a 0.17-mg/L lower hs-CRP.

However, adjusting for diet and lifestyle attenuated the link between whole grain intake and hs-CRP. In particular, controlling for fibre consumption strongly minimized such interaction. This effect may be explained by the association between fibre intake itself and hs-CRP concentration. Each 50-g/day increase in fibre consumption was found to lower hs-CRP by a significant 0.11-mg/L.

According to the researchers, such an interaction suggests that cereal fibres may partly account for the link between whole grains and hs-CRP.

In contrast, hs-CRP levels were directly correlated with refined grain consumption. Even in the fully controlled regression model, a 0.50-g/day increase in refined grain intake led to a significant 0.20-mg/L increase in hs-CRP.