POTCHEFSTROOM, South Africa—In the presence of weight loss and modified saturated, monounsaturated and polyunsaturated fat intakes, significantly lower C-reactive protein (CRP) concentrations are seen with increased fiber consumption (3.3 g/MJ), according to South African researchers (Eu J Clin Nutr. 2009;63:92133). Databases were searched from the earliest record to April 2008 and supplemented by crosschecking reference lists of relevant publications. Human adult intervention trials, at least two weeks in duration, with an increased and measurable consumption of dietary fiber were included and rated for quality.
Seven clinical trials were included, and six of these reported significantly lower CRP concentrations of 25 to 54 percent with increased dietary fiber consumption with dosages ranging between 3.3 to 7.8 g/MJ. The seventh trial with psyllium fiber supplementation failed to lower CRP levels significantly in overweight/obese individuals. Weight loss and altered fatty acid intakes were present in most of the studies.Mechanisms are inconclusive but may involve the effect of DF on weight loss, and/or changes in the secretion, turnover or metabolism of insulin, glucose, adiponectin, interleukin-6, free fatty acids and triglycerides. Clinical studies of high- and low-fiber diets are needed to explore the potential favorable effects as observed epidemiologically, and to understand individual susceptibility to its anti-inflammatory effect and long-term cardiovascular reduction.