Consumption of soybean, soy foods, soy isoflavones and breast cancer incidence: Differences between Chinese women and women in Western countries and possible mechanisms

Hypolipidemic and antioxidant effects of Morus alba L. (Egyptian mulberry) root bark fractions supplementation in cholesterol-fed rats.

The hypocholesterolemic effect of soy is well-documented and this has led to the regulatory approval of a health claim relating soy protein to a reduced risk of cardiovascular disease (CVD). However, soybeans contain additional components, such as isoflavones, lecithins, saponins and fiber that may improve cardiovascular health through independent mechanisms. This review summarizes the evidence on the cardiovascular benefits of non-protein soy components in relation to known CVD risk factors such as hypertension, hyperglycemia, inflammation, and obesity beyond cholesterol lowering. Overall, the available evidence suggests non-protein soy constituents improve markers of cardiovascular health; however, additional carefully designed studies are required to independently elucidate these effects. Further, work is also needed to clarify the role of isoflavone-metabolizing phenotype and gut microbiota composition on biological effect.

Beyond the Cholesterol-Lowering Effect of Soy Protein: A Review of the Effects of Dietary Soy and Its Constituents on Risk Factors for Cardiovascular Disease.

Objectives: Many randomized controlled trials (RCTs) have assessed the effects of soy protein on serum lipoprotein risk factors for coronary heart disease (CHD). This review and meta-analysis assessed the quality of these RCTs and estimated the effects of soy protein consumption on serum lipoproteins.Data Sources: A comprehensive search using multiple databases was conducted for the years 1996 through 2008 to identify clinical trials related to soy protein intake and serum lipoprotein changes.Study Eligibility: RCTs were assessed that met these requirements: soy protein intake compared with nonsoy protein, provided information on serum low-density lipoprotein (LDL)-cholesterol values, provided no more than 65 g of soy protein daily, and obtained LDL-cholesterol measurements between 4 and 18 weeks of treatment. Randomized parallel and crossover studies were evaluated.Methods: Studies were graded for quality using 12 criteria with a possible maximum grade of 24. Net changes in lipoproteins with soy protein ...

Soy Protein Effects on Serum Lipoproteins: A Quality Assessment and Meta-Analysis of Randomized, Controlled Studies

The metabolic syndrome (MS) is a cluster of metabolic derangements that are associated with primary disturbances in adipose tissue. Abnormal visceral fat accumulates from physical inactivity and excess calories in genetically susceptible individuals. This increased adipocyte mass acts as an endocrine organ and communicates with other organ systems via increases in inflammatory cytokines. The resulting disorders define MS as increased waist circumference, decreased serum high-density lipoprotein, and increased serum triglyceride levels, hypertension, and insulin resistance. MS accounts for the majority of cardiovascular disease risk in the U.S. population. Dietary interventions, such as the Mediterranean diet, have been shown to improve these metabolic derangements. Many substances found in these diets are being investigated as specific therapies for MS, and when scientific substantiation is lacking, they may be considered as part of complementary and alternative medicine (CAM). However, as scientific evidence accumulates, these CAM treatments may become part of conventional medicine. This review will scrutinize the emerging evidence behind many, though not all, CAM treatments currently thought to target the various derangements found in MS.

The metabolic syndrome: definition, global impact, and pathophysiology.

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 (Abacor® 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.

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

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. 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. 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. 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. 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.

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

Eve C A Morgenstern

Papers

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

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