Metabolic effects of dietary fiber from dehulled soybeans in humans

Abstract

The normal diet of six healthy volunteers was supplemented by 21 g of dietary fiber from two different soybean seed fiber preparations, either a nonpurified and never-dried soya pulp A (39% dietary fiber) or a purified soya fiber B (79%), for 3 wk each. Mean daily fecal wet weight was increased by 19 and 38% in the fiber periods A and B as compared to a 2-wk control period (p less than 0.05). Stool frequency and transit time remained unchanged. Fecal fiber increased by 52% only during period B. Fecal calcium, magnesium, and iron were increased (p less than 0.05), mainly after higher intakes during both fiber periods. Excretion of neutral steroids remained unchanged, but their concentration was lowered (p less than 0.05). A 21% increase of fecal bile acids by fiber A was specifically due to deoxycholic acid (+32%, p less than 0.01). Oral glucose tolerance was slightly improved after period B. Neither fiber changed serum triglycerides, but fiber B increased low-density lipoprotein-cholesterol by 19% (p less than 0.01) and low-density lipoprotein-phospholipids by 16% (p less than 0.05). The ratio high-density/low-density lipoprotein-cholesterol, however, did not change significantly. Thus, dietary fibers from soybean do not seem to contribute to the hypocholesterolemic effect of soya. The results of this study also demonstrate that two apparently similar dietary fibers, coming from a single source, can exert distinctly different metabolic effects.

Bile acid and cholesterol excretion in human beings given soya-bean-and meat-protein-based diets: a study in ileostomy subjects

“…These two cruder preparations contain larger amounts of dietary fibre than the soya-bean isolate, which might produce at least part of this effect. This would be in accordance with studies on soya-bean fibre (Tsai et al 1983), although different soya-beanfibre preparations may have different effects (Schweizer et al 1983). The decrease in sterol concentrations might be of some importance, as high faecal steroid concentrations have been implicated as a risk factor for cancer of the large intestine (Hill & …”

Constipation, dietary fibre and the control of large bowel function

“…If the carbohydrates in the fibres listed in Table 1 are measured chemically and the results of this , 1983;Cummings et aL, 1976Cummings et aL, , 1978Cummings et aL, , 1979aCummings et aL, and b, 1984Prynne and Southgate, 1979;Schweizer et al, 1983;Southgate et al, 1976. analysis compared to their effectiveness as faecal bulking agents then another relationship is evident (Fig. 1).…”

The Influence of Legume Seeds on Human Plasma Lipid Concentrations

“…Unlike guar gum, soya-bean polysaccharide concentrates have not been shown to reduce the cholesterol levels of normolipidaemic subjects, and may even raise them (Schweizer et al 1983 ;Tsai et al 1983). Nevertheless, some forms may be of benefit in the management of hyperlipidaemia.…”