Ultra heat treatment destroys cholesterol-lowering effect of soy protein.

A randomized, placebo-controlled, double-blind clinical study was performed to investigate the dose-dependent response of serum cholesterol after consuming an ultra-heat-treated milk containing a soy protein preparation. Eighty hypercholesterolemic subjects were assigned to one of four study groups receiving 12.5 or 25 g soy protein (active treatment) or casein (placebo) daily over a period of 4 weeks. The trial substances were provided as ready-made, ultra-heated milk preparations. Before and after the treatment, serum concentrations of total, low-density lipoprotein, and high-density lipoprotein cholesterol were determined. Unexpectedly, at the end of the study, low-density lipoprotein cholesterol concentrations were significantly increased compared with baseline in all study groups. The magnitude of this increase (17-19%) was similar in all active and placebo study groups. Soy protein supplements previously shown to be effective in reducing serum cholesterol had in this study no such lipid-lowering effect after ultra heat treatment.

Lipid-lowering effect of 2 dosages of a soy protein supplement in hypercholesterolemia.

The lipid-lowering effect of a soy-based protein supplement was evaluated in an 8-week randomized, placebo-controlled trial in patients with hypercholesterolemia. A total of 117 patients (63 men and 54 women) received soy protein, either 15 or 25 g/d or placebo. In the active treatment groups low-density lipoprotein cholesterol levels decreased significantly by 5.9% and 1.1% respectively, but increased by 3.6% with placebo. Total serum cholesterol and apolipoprotein B levels changed significantly in a similar manner. High-density lipoprotein cholesterol, triglycerides, homocysteine, folic acid, and vitamin B12 levels did not change significantly compared with baseline in any of the study groups. All preparations were well tolerated. Soy protein 25 g/d was twice as effective as 15 g/d. In conclusion, soy protein supplementation may effectively reduce serum cholesterol levels and therefore is likely to diminish the risk for cardiovascular disease.

Weight loss and lipid changes with low-energy diets: comparator study of milk-based versus soy-based liquid meal replacement interventions.

OBJECTIVES: Soy protein intake has favorable effects on body weight and fat distribution in experimental animals but these effects have not been demonstrated in humans. To compare effects of soy- vs. milk-based meal replacements (MR) we assessed weight loss and serum lipoproteins changes for obese subjects who consumed low-energy diets (LED) including either milk-based or soy-based MR. METHODS: Overweight or obese women and men (body mass indices 27-40 kg/m(2)) were randomly assigned to LED providing 1200 kcal/day, with consumption of five soy-based or two milk-based liquid MR for a 12-week weight loss trial. Serum lipoprotein measurements were obtained at baseline, 6 and 12 weeks. RESULTS: For soy and milk MR groups, subject numbers were, respectively, 51 and 39 randomized and 30 and 22 completers. MR use averaged: soy, 3.7/day; and milk, 1.9/day. Weight losses for completers at 12 weeks were: soy MR, 9.0% of initial body weight (95% confidence intervals, 7.3-10.6%); and milk MR, 7.9% (5.8-8.8%) with no significant differences. Reductions from baseline in serum cholesterol and LDL-cholesterol values, respectively, at six weeks were significantly greater (P < 0.015) with soy MR (15.2% and 17.4%) than with milk MR (7.9% and 7.7%). Soy MR use was associated with significant reductions in serum triglycerides at 6 and 12 weeks while milk MR use was not. CONCLUSIONS: Soy MR use, as part of a low-energy diet, was associated with slightly but not significantly greater weight loss over a 12-week period than milk MR use. These observations confirm previous studies documenting the effectiveness of MR use for weight loss.

A double-blind placebo-controlled clinical trial compares the cholesterol-lowering effects of two different soy protein preparations in hypercholesterolemic subjects.

BACKGROUND: Soy protein is effective in lowering plasma cholesterol, LDL cholesterol and triglyceride concentrations. It has not been conclusively answered, whether and to what extent other soy constituents may also contribute to this effect. OBJECTIVE: To investigate the change in blood lipid levels after application of two soy-based supplements containing soy protein either without (SuproSoy) or with (Abacor) soy fiber and phospholipids in a randomized placebo-controlled triplearmed study. METHODS: 121 hypercholesterolemic adults (66 females, 55 males) were recruited and randomly assigned to one of three treatments. Over 8 weeks they received daily either 25 g soy protein (as a component of the supplements Abacor or SuproSoy) or 25 g milk protein (as a component of placebo). Serum lipids were measured at baseline and after 4, 6 and 8 weeks. RESULTS: After 8 weeks of supplementation total cholesterol levels were reduced by 8.0 +/- 9.6% (Abacor) and 3.4 +/- 8.3% (SuproSoy); LDL cholesterol levels by 9.7 +/- 11.7% (Abacor) and 5.4 +/- 11.6% (SuproSoy); and Apolipoprotein B levels by 6.9 +/- 14.6% (Abacor) and 4.0 +/- 12.4 % (SuproSoy). Serum levels of HDL cholesterol and triglycerides remained unchanged. CONCLUSIONS: A preparation combining isolated soy protein with soy fibers and phospholipids showed twice the lipid-lowering effect of a preparation containing isolated soy protein alone. Therefore, such soy-based supplements can be useful in reducing the cardiovascular risk.

Structured weight-loss programs: meta-analysis of weight loss at 24 weeks and assessment of effects of intervention intensity.

Obesity is increasing in epidemic proportions globally while current therapies continue to be suboptimal. In this investigation, weight loss in obese individuals after 24 weeks with different nutrition interventions was compared. The impact of intervention intensity was assessed. Inclusion criteria were established and a comprehensive literature review was performed. These nutrition interventions were identified and analyzable: meal replacements (MRs); energy-restricted (>1500 kcal/d) diets (ERDs); low-energy (800-1500 kcal/d) diets (LEDs); soy very low energy (<800 kcal/d) diets (VLEDs) referred to as SOYs; and VLEDs. Intensity was assessed using the following parameters: physician visits, clinic visits, and hours of class over 24 weeks; an intensity score represents an adjusted sum of the values. Weight losses at 24 weeks as percentage of baseline weights (95%, confidence intervals) were as follows: MRs, 9.1% (5.7-12.5); ERDs, 8.5% (4.9-12.1); LEDs, 11.4% (8.9-13.1); SOYs, 16.5% (13.9-19.1); and VLEDs, 21.3% (20.1-22.5). Weight loss with SOYs was significantly greater than with MRs and ERDs; weight loss with VLEDs was significantly greater than with any other diet. Energy intake was the most significant (P<.0001) regression variable related to weight loss; however, the intensity of intervention (P=.0003) was significantly stronger than initial body weight or duration of treatment. Medically supervised VLEDs are the most effective intervention for facilitating substantial weight loss over 24 weeks. SOY may promote more rapid weight loss over the first 8 weeks than other interventions. MRs appear to be equally effective with ERDs and LEDs with lower levels of intervention intensity.

Isolated soya protein with standardised levels of isoflavones, cotyledon soya fibres and soya phospholipids improves plasma lipids in hypercholesterolaemia: a double-blind, placebo-controlled trial of a yoghurt formulation.

The objective was to study whether a yoghurt containing isolated soya protein with standardised levels of isoflavones, cotyledon soya fibres and soya phospholipids is more effective in lowering total and LDL-cholesterol than a placebo. One hundred and forty-three subjects were randomised to the soya group (n 69) or to the placebo (n 74). The mean baseline levels were 7.6 and 5.1 mmol/l for total and LDL-cholesterol, respectively. Fasting serum lipoproteins were assessed five times during the 8-week intervention period, and 4 weeks thereafter. The results were analysed by a mixed model for unbalanced repeated measurements. During the intervention, there were highly significant differences in lipid-lowering effect in favour of the active soya intervention group compared with the control group. The significant differences were for total cholesterol (estimated mean difference 0.40 mmol/l; P<0.001), LDL-cholesterol (0.39 mmol/l; P<0.001), non-HDL-cholesterol (0.40 mmol/l; P<0.001) and for the total:HDL-cholesterol ratio (0.23; P=0.005). There was no difference in the effects on HDL-cholesterol, triacylglycerols or homocysteine. The lipid-lowering effect occurred within 1-2 weeks of intervention, and was not due to weight loss. The safety profile for active soya was similar to the placebo group, except for gastrointestinal symptoms, which caused a significantly higher dropout rate (fourteen v. three subjects) among the subjects taking active soya.

Effects of soy and other natural products on LDL:HDL ratio and other lipid parameters: a literature review.

Abnormal lipid levels contribute significantly to the risk of coronary heart disease, a major cardiovascular disease and a serious health problem. Various dietary and pharmacologic treatments have been devised to reduce elevated blood cholesterol levels. Soy protein, soluble fiber, and plant sterol/ester-containing margarines are promising new food-component candidates that may help to realize this goal. Of particular interest in this context is the LDL:HDL ratio, a strong predictor of cardiac events. This report is a review of more than 50 recent trials to determine how such dietary components and garlic affect the LDL:HDL ratio and other lipid parameters. Consumption of new soy products containing high, fixed levels of isoflavones, cotyledon soy fiber, and soy phospholipids (Abaco and Abalon) significantly reduced the LDL:HDL ratio by up to 27%. Soluble dietary fibers such as psyllium and beta glucan from oat bran had a variable effect on LDL-cholesterol levels in the studies analyzed. Plant sterol esters, when consumed in margarines, lowered the LDL:HDL ratio by up to 22%. On average, Abacor and Abalon reduced the LDL:HDL ratio by 20%, LDL cholesterol by 15%, total cholesterol by 10%, and triglycerides by 6%, and increased HDL cholesterol by 5%. The new soy-based supplements may therefore play a valuable role in reducing cardiovascular risk.