terol concentrations by 7.7 to 8.9 percent (MacMahon and Carless, 1998). Danielsson and coworkers (1979) treated 13 patients with essential hyperlipoproteinemia over 2 to 29 months with psyllium hydrophilic colloid. Serum cholesterol and triacylglycerol concentrations were reduced an average of 16.9 and 52.0 percent, respectively. If blood lipid concentrations were normal at baseline, no reductions were observed when individuals consumed psyllium colloid (Danielsson et al., 1979).

Studies also have been conducted using a ready-to-eat cereal enriched with psyllium. Hypercholesterolemic individuals consuming 114 g/d of a psyllium-flake cereal for 6 weeks showed significantly lower serum total and LDL cholesterol concentrations than those consuming the same amount of wheat-bran flake cereal (Anderson et al., 1992b). Similarly, Bell and coworkers (1990) tested the cholesterol-lowering effects of viscous fiber (psyllium or pectin) cereals as part of a diet in 58 men with mild to moderate hypercholesterolemia. During the cereal-plus-diet phase of the study, total and LDL cholesterol concentrations in the psyllium-enriched cereal group decreased by 5.9 and 5.7 percent, respectively.

A meta-analysis was conducted to determine the effect of consumption of psyllium-enriched cereal products on blood lipid concentrations in 404 adults with mild to moderate hypercholesterolemia consuming a low fat diet (Olson et al., 1997). Compared to the control cereals, individuals who consumed psyllium cereals had lower total and LDL cholesterol concentrations, whereas HDL cholesterol concentrations were not affected. Anderson and coworkers (2000a) conducted a meta-analysis of eight controlled trials to define the hypolipidemic effects of psyllium when used in combination with a low fat diet in hypercholesterolemic men and women. There were a total of 384 individuals receiving psyllium in the eight studies covered by the meta-analysis and these individuals were compared to those consuming cellulose (n = 272). Consumption of 10.2 g/d of psyllium (n = 384) lowered serum total cholesterol by 4 percent and serum LDL cholesterol by 7 percent, relative to the cellulose control (n = 272).

Everson and colleagues (1992) evaluated the mechanisms of the hypocholesterolemic effect of psyllium by measuring intestinal cholesterol absorption, cholesterol synthesis in isolated peripheral blood mononuclear cells, bile acid kinetics, gallbladder motility, and intestinal transit. The researchers concluded that psyllium decreases LDL cholesterol concentrations mainly by the stimulation of bile acid production.

Attenuation of Blood Glucose Responses. In an 8-week intervention study in 34 men with type 2 diabetes and hypercholesterolemia consuming either 10.2 g/d of psyllium or cellulose, daily and postlunch postprandial glucose concentration were 11.0 and 19.2 percent lower, respectively, in the psyllium group (Anderson et al., 1999). Also, psyllium has been shown to