Effects of diet supplementation with three soluble polysaccharides on serum lipid levels of hypercholesterolemic rats

Some soluble polysaccharides have been explored as possible ingredients in the development of “functional foods” because of their ability to reduce plasma cholesterol and consequently contribute to the reduction of the risk of cardiovascular disease. However, this effect has been predominantly observed in studies using megadoses that are incompatible with the pattern of human consumption. On the basis of this limitation, the objective of the present study was to assess the hypocholesterolemic effect of the ingestion of three different hydrocolloids (guar gum, xanthan gum and pre-gelatinised cornstarch) at 1.5% concentration in an assay on rats. Cellulose was used as control. In the first stage of the experiment, all animals were fed a hypercholesterolemic diet that produced a mean concentration of total cholesterol (5.2 mmol/l) significantly higher than in the group fed a control diet (1.0 mmol/l). In the subsequent stage, 1.5% of the starch was replaced with each of the three hydrocolloids in the experimental ration. Food intake and body weight gain were not altered by the hydrocolloid diets (P<0.05). Serum cholesterol concentrations were 1.43, 1.41, 1.54 and 1.42 mmol/l for the diets containing guar gum, xanthan gum, pre-gelatinized cornstarch and cellulose, respectively. We conclude that, under the conditions of the present study, the hypocholesterolemic effect of hydrocolloid ingestion at a dose of 1.5% of the ration was not significant in comparison to the effect produced by the reduction and change of lipids in the diet. Thus, more attention should be paid to the use of hydrocolloids in functional foods, always considering the balance of the diet as a whole.