06.01.10
Nutraceutical: Soy and a prebiotic
Indication: Cardiovascular health
Source: Metabolism, January 21, 2010 [Epub ahead of print].
Research: The value of soy protein as part of a cholesterol-lowering diet has been questioned by recent studies. The apparent lack of effect may relate to the absence of dietary factors that increase colonic fermentation and potentiate the cholesterol-lowering effect of soy. Therefore, unabsorbable carbohydrates (prebiotics) were added to the diet with the aim of increasing colonic fermentation and potentially increasing the hypocholesterolemic effect of soy. Researchers evaluated 23 hyperlipidemic adults over 50 (11 male, 12 female) in a randomized, controlled crossover study. The subjects completed three 4-week diet intervention phases: a low-fat dairy diet plus 10 grams per day of the prebiotic inulin; a soy food-containing diet (30 grams per day soy protein, 61 mg/d isoflavones from soy foods) plus 10 grams per day of placebo (maltodextrin); and a soy food-containing diet with 10 grams per day of inulin.
Results: Intake of soy plus the prebiotic resulted in greater reductions in LDL-C and in ratio of LDL-C to high-density lipoprotein cholesterol. In addition, HDL cholesterol significantly increased. Researchers believe soy foods in conjunction with a prebiotic may improve lipid profiles, which was not seen when either the prebiotic or soy alone was taken. Coingestion of a prebiotic may potentiate the effectiveness of soy foods as part of the dietary strategy to lower serum cholesterol.