The effects of dietary fibre on C-reactive protein, an inflammation marker predicting cardiovascular disease.
BACKGROUND
C-reactive protein (CRP), a sensitive marker of inflammation, is an independent predictor of future cardiovascular disease (CVD), which is a major cause of death worldwide. In epidemiological trials, high-fibre intakes have consistently been associated with reduction in CVD risk and CRP levels.


OBJECTIVE
The objective of this study was to assess the influence of dietary fibre (DF) on CRP in clinical trials.


METHODS
Databases were searched from the earliest record to April 2008 and supplemented by crosschecking reference lists of relevant publications.


METHODS
Human adult intervention trials, at least 2 weeks in duration, with an increased and measurable consumption of DF were included and rated for quality.


RESULTS
Seven clinical trials were included, and six of these reported significantly lower CRP concentrations of 25-54% with increased DF consumption with dosages ranging between 3.3-7.8 g/MJ. The seventh trial with psyllium fibre 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.


CONCLUSIONS
In the presence of weight loss and modified saturated, monounsaturated and polyunsaturated fat intakes, significantly lower CRP concentrations (downward arrow 25-54%) are seen with increased fibre consumption (> or =3.3 g/MJ). 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-fibre diets are needed to explore the potential favourable effects as observed epidemiologically, and to understand individual susceptibility to its anti-inflammatory effect and long-term cardiovascular reduction.
North
C J
CJ
School of Physiology, Nutrition and Consumer Sciences, North-West University, Potchefstroom, South Africa.
Venter
C S
CS
Jerling
J C
JC
D000328:Adult; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism*; D002986:Clinical Trials as Topic; D004041:Dietary Fats; D004043:Dietary Fiber / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D007249:Inflammation / Q000097:blood*; D015431:Weight Loss
D015415:Biomarkers; D004041:Dietary Fats; D004043:Dietary Fiber; D002097:C-Reactive Protein