Effects of supplementation with rice husk powder and rice bran on inflammatory factors in overweight and obese adults following an energy-restricted diet: a randomized controlled trial.

PURPOSE: Overweight and obesity are major public health concerns worldwide which are associated with a low-grade chronic inflammation. Dietary fiber as an important component of diet could be effective in controlling weight and inflammatory factors. The present study aimed to compare the effects of rice husk powder and rice bran on inflammatory factors along with an energy-restricted diet in overweight and obese adults.

METHODS: In this randomized trial, 105 eligible individuals were assigned to one of the three energy-restricted diet groups receiving; rice bran (n = 35), rice husk powder (n = 35), and control group (n = 35) for 12 weeks. Demographic data, dietary intake, anthropometric indices and inflammatory factors (serum levels of IL-6 and hs-CRP) were measured at baseline and at the end of the study.

RESULTS: Weight, BMI and waist circumference reduced significantly in all groups after 12 weeks of study (P < 0.01 for all). However, pre- and post-measure differences between groups were not significant. Moreover, serum levels of hs-CRP and IL-6 were not significantly different between participants in the rice bran or rice husk groups. However, the reduction in serum levels of hs-CRP in rice husk (mean change = - 0.14 ± 0.05 µg/ml) and rice bran (mean change = - 0.13 ± 0.03 µg/ml) was significantly higher when compared to the control group (mean change = - 0.03 ± 0.02 µg/ml) (P < 0.05 for both groups). The same pattern was found when changes in IL-6 serum levels of participants in rice husk (mean change = - 0.48 ± 0.11 pg/ml) and rice bran (mean change = - 0.57 ± 0.13 pg/ml) groups were compared to the control group (mean change= - 0.19 ± 0.07 pg/ml) (P < 0.05 for both groups).

CONCLUSION: The results of this study showed positive effects of rice bran and rice husk powder supplementation, combined with an energy-restricted diet, on inflammatory markers among overweight and obese adults.