Effect of dietary fiber and protein intake on blood pressure: A review of epidemiologic evidence

Observational epidemiologic studies identify an inverse relationship between dietary fiber and protein intake and blood pressure. This relationship has been demonstrated in both cross-sectional and prospective cohort studies and among various populations. Few randomized trials have examined the effect of dietary fiber and protein supplementation on blood pressure. In general, these intervention studies suggest that dietary fiber intake may lower blood pressure. However, they do not confirm the observational relationship between dietary protein and blood pressure. Furthermore, there are many limitations in the design of these clinical trials. Carefully designed randomized controlled trials with sufficient sample size to recognize a 2-3 mm Hg change in brood pressure using well-characterized dietary fiber and protein preparations are needed to confirm or refute these observed effects.