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Soy/milk protein dietary supplements linked to lower blood pressure
American Heart Association Rapid Access Journal Report
Study Highlights:
· Soy and milk protein dietary supplements lowered systolic blood pressure compared to refined (simple) carbohydrate supplements.
· Researchers suggest that replacing dietary refined carbohydrates with foods or drinks high in soy or milk protein might help prevent or treat high blood pressure.
Non-isoflavone Phytochemicals in Soy and Their Health Effects
Kang J, Badger TM, Ronis MJ, Wu X. J Agric Food Chem. 2010 Jun 25.
Epidemiological and clinical studies have linked consumption of soy foods with low incidences of a number of chronic diseases, such as cardiovascular diseases, cancer, and osteoporosis. Over the past decades, enormous research efforts have been made to identify bioactive components in soy. Isoflavones and soy protein have been suggested as the major bioactive components in soy and have received considerable attention. However, there are hundreds of phytochemical components in soybeans and soy-based foods. In recent years, accumulating evidence has suggested that the isoflavones or soy proteins stripped of phytochemicals only reflect certain aspects of health effects associated with soy consumption. Other phytochemicals, either alone or in combination with isoflavones or soy protein, may be involved in the health effects of soy. This review attempts to summarize major non-isoflavone phytochemicals in soy, as well as their bioavailability and health effects. In addition, a brief discussion of components formed during food processing is also included.
Source: U.S. National Library of Medicine
A vegetable-fruit-soy dietary pattern protects against breast cancer among postmenopausal Singapore Chinese women
Butler LM, Wu AH, Wang R, Koh WP, Yuan JM, Yu MC. Am J Clin Nutr. 2010 Feb 24. [Epub ahead of print]
BACKGROUND: Prospective epidemiologic studies in Asian populations consistently show that soy is protective against breast cancer. OBJECTIVE: The objective was to prospectively evaluate whether the protective effect of soy is due to soy isoflavones alone or to their combination with other beneficial dietary factors in an Asian population. DESIGN: Using principal components analysis, we previously identified a "meat-dim sum" pattern characterized by meat, starch, and dim sum items and a "vegetable-fruit-soy" pattern characterized by cruciferous vegetables, fruit, and tofu items in a population-based cohort of Singapore Chinese initiated between 1993 and 1998. Component scores representing intakes of each pattern were used in multivariable Cox regression models to analyze the relation between diet at baseline and breast cancer incidence. RESULTS: As of 31 December 2005, 629 incident breast cancer cases had been diagnosed among the 34,028 women. With greater intake of the vegetable-fruit-soy dietary pattern, we observed a dose-dependent trend (P < 0.01) for decreasing breast cancer risk among postmenopausal women [hazard ratio (HR): 0.70; 95% CI: 0.51, 0.95 for the fourth compared with first quartile]. A stronger association for the vegetable-fruit-soy pattern was observed among postmenopausal women with >/=5 y of follow-up (HR: 0.57; 95% CI: 0.36, 0.88; P for trend <0.01). No trend was observed for a greater intake of the meat-dim sum dietary pattern and increased breast cancer risk. CONCLUSION: Our findings support the hypothesis that a diet characterized by vegetables, fruit, and soy has an early-acting protective effect on breast carcinogenesis.
Relationship between dietary soy isoflavones and blood lipid levels in 40 - 65 year-olds in Guangzhou
Zhang B, Cai L, Su M, Zhou XX, Huang LL, Chen CG, Gan RY, Chen RQ, Su YX. Zhonghua Liu Xing Bing Xue Za Zhi. 2009 Aug;30(8):761-5.
OBJECTIVE: To study the relationship between dietary soy isoflavones and blood lipids among residents of 40 - 65 years old, in Guangzhou. METHODS: Dietary soy isoflavones and other nutrients intakes were assessed with quantitative food frequency questionnaire (FFQ). Total cholesterol (TC), triglycerides (TG), HDL cholesterol (HDL-C) and LDL cholesterol (LDL-C) in plasma were measured with colorimetry. RESULTS: Ranges of dietary soy isoflavones intake among 134 males and 261 females were from 0 mg/day to 61.96 mg/day and 0 mg/day to 82.52 mg/day, with means of 11.95 mg/day, 14.90 mg/day, respectively. After adjusted for total energy intake and fat percent energy, differences of TC, LDL-C in total population and TC in women were statistically significant between groups (P value was 0.002, 0.008, 0.004, respectively) and dose-effect relationships (P value was < 0.001, 0.012, 0.001, respectively) were observed between dietary soy isoflavones intake and the upper mentioned three indices. Compared with the low-intake group, these three indices lowered 7.06%, 10.13% and 7.48%, respectively in high-intake group. Critical significance of LDL-C was observed both in women and men between groups. Further controlled for age, BMI and WHR, no obvious change of the results was observed. CONCLUSION: Moderate intakes of soy isoflavone as part of a regular diet seemed to be associated with favorable blood lipid levels.
Dietary intake of isoflavones and polyunsaturated fatty acids associated with lung function, breathlessness and the prevalence of chronic obstructive pulmonary disease: Possible protective effect of traditional Japanese diet.
The Japanese diet is high in soy products and fish. A case-control study was conducted in Japan to investigate the relationship between dietary intake of isoflavones and fatty acids and lung function, breathlessness and chronic obstructive pulmonary disease (COPD). A total of 278 referred patients aged 50-75 years with COPD diagnosed within the past 4 years, and 340 community-based controls were assessed for respiratory symptoms and undertook spirometric measurements of lung function. A validated food frequency questionnaire was administered face-to-face to obtain information on habitual food consumption. Dietary intakes of isoflavones and fatty acids were derived from the Japanese food composition tables. The COPD patients had significantly lower habitual intakes of isoflavones (genistein and daidzein) and polyunsaturated fatty acids (PUFA; both omega-3 and omega-6) than control subjects. Lung function measures were found to be positively associated with isoflavones and PUFA intake. Substantial reductions in prevalence of COPD and breathlessness were observed for isoflavones, the respective adjusted odds ratio being 0.36 (95% confidence interval 0.19-0.68) and 0.60 (95% confidence interval 0.33-1.10) for the highest versus lowest levels of total isoflavone intake. The corresponding tests for linear trend were significant. High intakes of PUFA and omega-6 fatty acids (derived from foods excluding oils and fats as seasonings) also appeared to reduce the risks of COPD and breathlessness symptom, but no evidence of association was found for other types of fatty acids. The study provided evidence of possible protective effect of traditional Japanese diet against tobacco carcinogens.
Soy consumption and risk of COPD and respiratory symptoms: a case-control study in Japan.
BACKGROUND: To investigate the relationship between soy consumption, COPD risk and the prevalence of respiratory symptoms, a case-control study was conducted in Japan. METHODS: A total of 278 eligible patients (244 men and 34 women), aged 50-75 years with COPD diagnosed within the past four years, were referred by respiratory physicians, while 340 controls (272 men and 68 women) were recruited from the community. All participants underwent spirometric measurements of respiratory function. Information on demographics, lifestyle characteristics and habitual food consumption was obtained using a structured questionnaire. RESULTS: Total soy consumption was positively correlated with observed lung function measures. The mean soy intake was significantly higher among controls (59.98, SD 50.23 g/day) than cases (44.84, SD 28.5 g/day). A significant reduction in COPD risk was evident for highest versus lowest quartile of daily intake of total soybean products, with adjusted odds ratio (OR) 0.392, 95% CI 0.194-0.793, p for trend 0.001. Similar decreases in COPD risk were associated with frequent and higher intake of soy foods such as tofu and bean sprouts, whereas respiratory symptoms were inversely associated with high consumption of soy foods, especially for breathlessness (OR 0.989, 95% CI 0.982-0.996). CONCLUSION: Increasing soy consumption was associated with a decreased risk of COPD and breathlessness.
Isoflavone intake and risk of lung cancer: a prospective cohort study in Japan.
BACKGROUND: Although case-control studies support the idea that soy foods or isoflavone intake is associated with a decreased risk of lung cancer, little evidence is available from prospective cohort studies. Moreover, no prospective study has addressed this association in men. OBJECTIVE: We investigated the association between isoflavone intake and lung cancer incidence. DESIGN: We conducted a population-based prospective cohort study in 36,177 men and 40,484 women aged 45-74 y with no history of cancer at baseline in 1995-1999. Participants responded to a validated questionnaire, which included 138 food items. We used Cox proportional hazards regression analysis to estimate the hazard ratios (HRs) and 95% CIs of lung cancer incidence according to isoflavone intake, which was estimated by genistein content from soy foods. RESULTS: During 11 y (671,864 person-years) of follow-up, we documented 481 male and 178 female lung cancer cases. In men we found an inverse association between isoflavone intake and risk of lung cancer in never smokers (n = 13,051; multivariate HR in the highest compared with the lowest quartile of isoflavone intake: 0.43; 95% CI: 0.21, 0.90; P for trend = 0.024) but not in current or past smokers. A similar, nonsignificant inverse association was seen in never-smoking women (n = 38,211; HR: 0.67; 95% CI: 0.41, 1.10; P for trend = 0.135). We also tested effect modification by smoking status (P for interaction = 0.085 in men and 0.055 in men and women combined). CONCLUSION: In a large-scale, population-based, prospective study in Japan, isoflavone intake was associated with a decreased risk of lung cancer in never smokers.
Soy Isoflavone Intake Lowers Serum LDL Cholesterol: A Meta-Analysis of 8 Randomized Controlled Trials in Humans
Clinical trials have noted hypocholesterolemic effects of soy protein intake, but the components responsible are not known. This meta-analysis of 8 randomized controlled trials was conducted to more precisely evaluate the effects of isoflavones on blood LDL cholesterol concentration independently of soy protein level.
PubMed was searched for English-language “randomized controlled trial” articles published from 1966 to 2003 that described the effects of soy protein isolate (SPI) intake with measured isoflavone levels on blood lipids in humans using the search terms “soy protein,” “isoflavones,” and “cholesterol.” From 31 articles identified by the search, 8 articles (with 10 low vs. high isoflavone comparisons) were selected for the meta-analysis. Subjects in each comparison consumed similar dietary fat, cholesterol, and fiber; the reported body weight of subjects did not change significantly during treatment. Serum LDL cholesterol concentration in subjects who consumed SPI (mean 50 g/d) with high isoflavone content (mean intake 96 mg/d) decreased by 0.15 mmol/L (95% CI: 0.08 to 0.23 mmol/L; P 0.0001) compared with those who consumed the same SPI level with low isoflavone content (mean intake 6 mg/d). Decreases in serum LDL cholesterol concentration in hypercholesterolemic and normocholesterolemic subjects were 0.18 mmol/L (95% CI: 0.01 to 0.35 mmol/L; P 0.03) and 0.14 mmol/L (95% CI: 0.06, 0.23 mmol/L; P 0.0008), respectively. With identical soy protein intake, high isoflavone intake led to significantly greater decreases in serum LDL cholesterol than low isoflavone intake, demonstrating that isoflavones have LDL cholesterol–lowering effects independent of soy protein.
Meta-analysis of the effects of soy protein containing isoflavones on the lipid profile
Soy protein with isoflavones intact was associated with significant decreases in serum total cholesterol (by 0.22 mmol/L, or 3.77%), LDL cholesterol (by 0.21 mmol/L, or 5.25%), and triacylglycerols (by 0.10 mmol/L, or 7.27%) and significant increases in serumHDLcholesterol (by 0.04 mmol/L, or 3.03%). The reductions in total and LDL cholesterol were larger in men than in women.
Initial total cholesterol concentrations had a powerful effect on changes in total and HDL cholesterol, especially in subjects with hypercholesterolemia. Studies with intakes 80 mg showed better effects on the lipid profile. The strongest lowering effects of soy protein containing isoflavones on total cholesterol,LDLcholesterol,
and triacylglycerol occurred within the short initial period of intervention, whereas improvements in HDL cholesterol were only observed in studies of 12 wk duration. Tablets containing extracted soy isoflavones did not have a significant effect on total cholesterol reduction.
The association between soy nut consumption and decreased menopausal symptoms.
BACKGROUND: Epidemiological studies suggest a low incidence of hot flashes in populations that consume dietary soy. The present study examined the effect of soy nuts on hot flashes and menopausal symptoms. METHODS: Sixty healthy postmenopausal women were randomized in a crossover design to a therapeutic lifestyle changes (TLC) diet alone and a TLC diet of similar energy, fat, and protein content in which one-half cup soy nuts divided into three or four portions spaced throughout the day (containing 25 g soy protein and 101 mg aglycone isoflavones) replaced 25 g of nonsoy protein. During each 8-week diet period, subjects recorded the number of hot flashes and amount of exercise daily. At the end of each 8-week diet period, subjects filled out the menopausal symptom quality of life questionnaire. RESULTS:Compared to the TLC diet alone, the TLC diet plus soy nuts was associated with a 45% decrease in hot flashes (7.5 +/- 3.6 vs. 4.1 +/- 2.6 hot flashes day, respectively, p < 0.001) in women with >4.5 hot flashes/day at baseline and 41% in those with Soy isoflavones significantly decreased serum total cholesterol by 0.10 mmol/L (3.9 mg/dL or 1.77%; P 0.02) and LDL cholesterol by 0.13 mmol/L (5.0 mg/dL or 3.58%; P 0.0001); no significant changes in HDL cholesterol and triacylglycerol were found. Isoflavone-depleted soy protein significantly decreased LDL cholesterol by 0.10 mmol/L (3.9 mg/dL or 2.77%; P 0.03). Soy protein that contained enriched isoflavones significantly decreased LDL cholesterol by 0.18 mmol/L (7.0 mg/dL or 4.98%; P0.0001) and significantly increased HDL cholesterol by 0.04 mmol/L (1.6 mg/dL or 3.00%; P0.05). The reductions inLDLcholesterol were larger in the hypercholesterolemic subcategory than in the normocholesterolemic subcategory, but no significant linear correlations were observed between reductions and the starting values. No significant linear correlations were found between reductions in LDL cholesterol and soy protein ingestion or isoflavone intakes. Significant difference was found in 24-hour urinary isoflavone excretion between the two groups after intervention. Significant reductions from the baselines were observed in systolic BP (SBP) and diastolic BP (DBP), TC and non-high density lipoprotein cholesterol (non-HDL-C) in the soy-containing diet group, but not in the olive oil containing active placebo group. Significant increases in high density lipoprotein cholesterol (HDL-C) were observed in both groups Cardiovascular disease (CVD) is the leading cause of death in women. Functional food consumption can play an important role in the prevention and treatment of CVD. The purpose of this review is to establish recommendations for the intake of functional food ingredients in a healthy diet, such as soy proteins and isoflavone, omega-3 fatty acids (FAs) from fish oils (FOs) including eicosapentaenoic acid (EPA) and docoshexaenoic acid (DHA) and plant sterols-(PS) enriched foods - for prevention and treatment of CVD in postmenopausal women. First, controversial results exist on CVD risk factors after intake of soy protein and isoflavone that indicates that further clinical studies need to be done to better understand their role in maintaining and improving cholesterol levels. However, since soy contains polyunsaturated fats, replacing some higher fat meat protein sources with soy products may contribute to cardiovascular health. Secondly, FOs, including EPA and DHA, have shown promising effects for lowering triglyceride levels. In addition, emerging research appears to show that omega-3 FAs may have additional health effects with improved arterial health and a reduction in oxidative stress in postmenopausal women. Thirdly, foods and beverages supplemented with PS may reduce cholesterol; therefore, are a worthy addition to interventions aimed at lowering heart disease risk in women. Overall, incorporating functional foods into a healthy diet may be beneficial in helping to reduce lipids levels and thus the risk of CVD. Hypercholesterolemia is a major modifiable risk factor for cardiovascular disease. Some, but not all, studies have shown that soy protein intake decreases total and low-density lipoprotein cholesterol and triglycerides and increases high-density lipoprotein cholesterol. The objective of this meta-analysis was to examine the effect of soy protein supplementation on serum lipid levels in adults. English language articles were retrieved by searching MEDLINE (1966 to February 2005) and the bibliographies of the retrieved articles. A total of 41 randomized controlled trials in which isolated soy protein supplementation was the only intervention and the net changes in serum lipids during intervention were reported. Information on study design, sample size, participant characteristics, intervention, follow-up duration, and treatment outcomes was independently abstracted using a standardized protocol. Using a random-effects model, data from each study were pooled and weighted by the inverse of their variance. Soy protein supplementation was associated with a significant reduction in mean serum total cholesterol (-5.26 mg/dl, 95% confidence interval [CI] -7.14 to -3.38), low-density lipoprotein cholesterol (-4.25 mg/dl, 95% CI -6.00 to -2.50), and triglycerides (-6.26 mg/dl, 95% CI -9.14 to -3.38) and a significant increase in high-density lipoprotein cholesterol (0.77 mg/dl, 95% CI 0.20 to 1.34). Meta-regression analyses showed a dose-response relation between soy protein and isoflavone supplementation and net changes in serum lipids. These results indicate that soy protein supplementation reduces serum lipids among adults with or without hypercholesterolemia. OBJECTIVE: This study investigated the effects of a soy-based low-calorie diet on weight control, body composition, and blood lipid profiles compared with a traditional low-calorie diet. METHODS: Thirty obese adults (mean body mass index 29-30 kg/m(2)) were randomized to two groups. The soy-based low-calorie group consumed soy protein as the only protein source, and the traditional low-calorie group consumed two-thirds animal protein and the rest plant protein in a 1200 kcal/d diet for 8 wk. A diet record was kept everyday throughout the study. Food intake was analyzed before and after the study. AIMS: To review current research on the effects of soy consumption on menopausal Epidemiologic studies have suggested that a high phytoestrogen intake is inversely associated with cardiovascular disease risk factors and the incidence of cardiovascular events. However, the relation between the intake of isoflavone, a major component of phytoestrogen, and vascular endothelial function and the In high-income countries, people are eating more and exercising less, resulting in an increase of body weight. In many developed countries, as much as half of the adult population are overweight and more than 25% obese. There are many conventional dietary approaches to weight management, recommended by the leading research and medical societies. However, only a few studies evaluated
Soy isoflavones lower serum total and LDL cholesterol in humans: a meta-analysis of 11 randomized controlled trials
Conclusions: Soy isoflavones significantly reduced serum total and LDL cholesterol but did not change HDL cholesterol and triacylglycerol. Soy protein that contained enriched or depleted isoflavones also significantly improved lipid profiles. Reductions in LDL cholesterol were larger in hypercholesterolemic than in normocholesterolemic subjects .
Effects of Dietary Intake of Soy Protein and Isoflavones on Cardiovascular Disease Risk Factors in High Risk, Middle-Aged Men in Scotland
Functional foods for cardiovascular disease in women
A meta-analysis of the effect of soy protein supplementation on serum lipids
In conclusion, replacing foods high in saturated fat, trans-saturated fat, and holesterol with soy protein may have a beneficial effect on coronary risk factors.
Effectiveness of a soy-based compared with a traditional low-calorie diet on weight loss and lipid levels in overweight adults.
Anthropometric data were acquired every week, and biochemical data from before and after the 8-wk experiment were compared. RESULTS: Body weight, body mass index, body fat percentage, and waist circumference significantly decreased in both groups (P < 0.05). The decrease in body fat percentage in the soy group (2.2%, 95% confidence interval 1.6-2.8) was greater than that in the traditional group 1.4%, 95% confidence interval -0.1 to 2.8). Serum total cholesterol concentrations, low-density lipoprotein cholesterol concentrations, and liver function parameters decreased in the soy-based group and were significantly different from measurements in the traditional group (P < 0.05). No significant change in serum triacylglycerol levels, serum high-density lipoprotein cholesterol levels, and fasting glucose levels was found in the soy or traditional group. CONCLUSION: Soy-based low-calorie diets significantly decreased serum total cholesterol and low-density lipoprotein cholesterol concentrations and had a greater effect on reducing body fat percentage than traditional low-calorie diets. Thus, soy-based diets have health benefits in reducing weight and blood lipids.
Soy consumption for reduction of menopausal symptoms
symptoms. METHODS: To review results of recent meta-analyses and individual clinical trials. MAIN RESULTS: One recent meta-analysis reported that isoflavone supplementation was associated with a 34% reduction in hot flashes, with increased efficacy as the baseline number of flashes and isoflavone dose increased. A second review concluded that consumption of at least 15 mg genistein, rather than total isoflavones, is responsible for the reduction in symptoms. Results of these two eviews are supported by most subsequent randomized controlled trials. CONCLUSIONS: Consumption of 30 mg/day of soy isoflavones (or at least 15 mg genistein) reduces hot flashes by up to 50 %. This total reduction includes that provided by "the placebo effect". The greatest benefit may be realized when the isoflavone-rich food or supplement is taken in divided doses by subjects who experience at least four hot flashes/day.
Isoflavone intake in persons at high risk of cardiovascular events
atherosclerotic burden remains unclear.
Objective:Weaimed to investigate the effects of various dietary soy isoflavone intakes on brachial artery flow-mediated dilation and mean maximum carotid intima–media thickness.
Design: We studied 126 consecutive patients (x SD age: 66.5 11.1 y; 69% male) at high risk of cardiovascular events (94% had documented coronary artery disease or stroke; 44% had diabetes). A validated food-frequency questionnaire was used to estimate their dietary intake after they achieved stable dietary patterns for 3 mo.
Results: The median intakes of isoflavone and soy protein were 5.5 (range: 2.2–13.3) mg/d and 1.2 (range: 0.4 –2.8) g/d, respectively.
Persons in the 4th quartile of daily isoflavone intake had significantly (P 0.05) greater flow-mediated dilation— but not mean maximum carotid intima–media thickness—than did those in the lower quartiles. After adjustment for potential confounders, a higher isoflavone intake in the 4th than in the 1st quartile (13.3 mg/d), but not a higher intake of soy protein, predicted an absolute 2.71% increase in flow-mediated dilation (relative increase: 103%; P 0.02) and a 0.17-mm decrease in mean maximum carotid intima–media thickness (relative decrease: 14.5%; P 0.04).
Conclusion: In persons at high risk of cardiovascular events, a greater isoflavone intake is associated with better vascular endothelial function and lower carotid atherosclerotic burden.
Weight loss without losing muscle mass in pre-obese and obese subjects induced by a high-soy-protein diet
their long-term efficacy with respect to body composition, for example, changes in muscle vs fat mass. The balance of macronutrients in a diet to lose weight is still in debate. Diets with a high proportion of carbohydrates may reduce the oxidation of body fat increase blood triglycerides and reduce satiety. On the other hand, protein-rich diets may reduce energy efficiency and increase hermogenesis, reduce the resting energy expenditure in response to a diet to a lesser extent spare muscle protein loss3 and enhance glycemic control.
We conducted a 6-month randomized, controlled trial to estimate the efficacy of a staged high-soy-protein and low-fat diet. The primary objectives were weight loss and a reduction in BMI of at least 2.5 kg/m2 after 6 months; a secondary objective was loss of fatmass and preservation of muscle mass.