The complete text of this article is available from www.ajcn.org/misc/10863.pdf
In the United States, 32% of adult men and 27% of adult women have undesirable serum cholesterol concentrations contributing to cardiovascular disease, the number one cause of death. Achieving reductions in total and LDL cholesterol may be helped by adding to the diet psyllium, a non-soluble fiber. Psyllium husks are the outer coating of the psyllium seed and are unique among dietary fiber additives for their positive effect on fecal bulking. In a meta-analysis of 8 different dietary studies, Anderson et al. of the University of Kentucky found that psyllium reduced serum cholesterol totals as well as LDL cholesterol levels over a treatment period of at least 8 weeks.
All 656 subjects in the 8 separate studies were hypercholestemic and received psyllium in addition to their previously-prescribed low-fat American Heart Association "Step I" diet. All subjects consumed psyllium in the usual laxative dose. The safety of psyllium consumption was also assessed across 19 different studies, and adverse health affects were found to be slight, with a nearly equal dropout rate (due to health affects) among those who took psyllium and those in the placebo group.
Over 8 weeks of treatment, overall decreases in cholesterol levels were encouraging: LDL cholesterol was reduced 6.72% ; and the LDL to HDL ratio decreased by 6.62%. The effect of psyllium appeared to focus on the reduction of LDL. In general, decreases in ratios of LDL to HDL cholesterol were greater in the older age group, with very little difference in results between men and women.
The question of how psyllium works to reduce cholesterol is still under investigation, but the authors propose that psyllium and other soluble fibers increase bile acid excretion and secondarily increase the excretion of cholesterol from the liver.