Soy isoflavones are often called phytoestrogens and are common health food for women during menopause. Do you know the benefits of soy isoflavones supplements?
The following will introduce why soy isoflavones are important and discuss the benefits and side effects.
Table of Contents
- What is soy isoflavone?
- Soy Isoflavone Food Source
- What are the benefits of soy isoflavones?
- 1. Soy isoflavones beneficial cognitive function
- 2. Soy isoflavones improve the symptoms of hot flashes in menopause
- 3. Soy isoflavones improve cholesterol
- 4. Soy isoflavones benefit osteoporosis
- 5. Soy isoflavones benefit blood sugar regulation
- 6. Soy isoflavones reduce the incidence of breast cancer
- 7. Soy isoflavones are beneficial for blood pressure regulation
- 8. Soy isoflavones reduce the risk of prostate cancer
- 9. Soy isoflavones help to lose weight (for menopausal women)
- Are there any side effects of soy isoflavones?
- Safety Precautions
- Where to buy soybean isoflavone capsules recommended by most people?
What is soy isoflavone?
Soy isoflavones are a type of flavonoids in soybeans. Daidzein and genistein are the two most common.
Soy isoflavones are structurally similar to estrogen (especially 17-β estradiol) and can cause weak estrogen effects or anti-estrogen effects depending on the endogenous estrogen and estrogen receptor.
In addition, like other flavonoids, it has many functions such as antioxidants, inhibition of cancer cell proliferation, anti-inflammatory, and antibacterial.
Interestingly, the incidence of breast and prostate cancer in Asians is lower than in Western countries, which may be related to the isoflavone-containing foods in Asian diets (15-47 mg/day) and Western diets (0.15-1.7 mg/day) There are significant differences in income.
Soy Isoflavone Food Source
- Content per 100g (mg/100g)
- Soybean: 26–381mg
- Soy flour: 83–466 mg
- Tofu (Tofu): 8–67 mg
- Miso (Miso): 25–89 mg
- Tempeh: 86.5 mg
What are the benefits of soy isoflavones?
1. Soy isoflavones beneficial cognitive function
As we age, cognitive function is essential for functional independence, including whether a person can live independently, manage money, take medication correctly, and drive safely.
All cognitive degradation is considered to start unconsciously and develop gradually. Mild Cognitive Impairment may represent this early stage.
The key criteria to distinguish between mild cognitive impairment and dementia are to maintain functional independence and lack of obvious impairment in social or occupational functions.
A systematic literature review and meta-analysis (including 16 randomized controlled trials with a total of 1386 participants) pointed out that soybean isoflavones (daily dose from 60 mg to 160 mg, median intervention duration was 17 weeks ) Can improve the cognitive function of adults, especially in the field of memory.
2. Soy isoflavones improve the symptoms of hot flashes in menopause
Hot flashes are the most common vasomotor symptoms in menopausal women. The symptoms are mainly intense fever, sweating, and flushing in the head, neck, chest, and upper back, and may be accompanied by rapid heartbeat, anxiety, nausea, And headaches.
Hot flashes usually last for 1 to 5 minutes, some even up to an hour, and the frequency of attacks generally decreases 5 to 7 years after menopause, but some women can last for more than 20 years, and the median duration of symptoms is about 4 years.
A meta-analysis of literature (including 17 double-blind randomized controlled trials) pointed out that the ingestion of soybean isoflavone capsules (median dose of 54 mg for 6 weeks to 12 months) can reduce the frequency of hot flashes by 20.6%, The degree of hot flashes decreased by 26.2%.
In addition, if the content of genistein in soy isoflavone supplements exceeds 18.8 mg, the effect of improving hot flashes is twice that of the lower content.
The underlying mechanism is related to the chemical and biological similarity of soybean isoflavones to mammalian estrogen and selective estrogen receptor modulation.
3. Soy isoflavones improve cholesterol
Although the normal aging process leads to a reduction in lean body mass and a reduction in metabolic rate, menopausal women tend to accelerate their weight gain in the first few years of endogenous estrogen decline.
Another physiological change is the change in blood lipids, including the rise of triglyceride, total cholesterol, and low-density lipoprotein cholesterol, and is usually related to the increase in abdominal fat.
A meta-analysis, including 12 randomized controlled trials on menopausal women with normal cholesterol values, indicated that compared to placebo, oral soy isoflavones (average daily dose of 70 mg, aglycone form, continued 1-3 months) There is no obvious help to improve total cholesterol and low-density lipoprotein cholesterol (LDL-C).
4. Soy isoflavones benefit osteoporosis
Osteoporosis is a multifactorial systemic skeletal disease characterized by low bone density and degeneration of bone tissue microstructure, resulting in brittle bones.
The most common sites of fragile bone fractures are the wrist, spine, buttocks, ribs, and humerus. The incidence has increased from 4% in women aged 50-59 to 52% in women aged 80.
Many factors, including age, gender, race (especially white people), genetics, reproductive status, low calcium intake, and exercise, can affect bone quality.
A systematic literature review and meta-analysis (including 28 randomized controlled trials) pointed out that for menopausal women, the intake of soybean isoflavones (daily 56 mg aglycone equivalents for 10 weeks to 12 months) can significantly reduce bone breakdown Indicators: deoxypyridinoline, DPD.
In addition, compared with placebo, the bone formation indicators of subjects who supplemented with soy isoflavones (daily doses of 84 and 73 mg for 12 months): bone alkaline phosphatase and osteocalcin increased by 8.0% and 10.3%, respectively, not reaching statistics Notable.
Another meta-analysis (including 12 randomized controlled trials, a total of 1240 menopausal women) pointed out that the intake of soybean isoflavones (average daily intake of 82 mg, lasting 6-12 months) can significantly increase spine bone density 22.25 mg/cm2 or 2.38% (but there was no significant improvement in bone density in the femoral neck, hip joint, and trochanter.
*Conclusion: For menopausal women, soy isoflavone supplements may be helpful for improving bone health and preventing osteoporosis, but limited by heterogeneity, more large-scale trials are still needed to corroborate.
5. Soy isoflavones benefit blood sugar regulation
Menopause is often associated with the accelerated development of glucose intolerance because low levels of estrogen can adversely affect the distribution and accumulation of body fat, appetite, energy expenditure, insulin secretion, and glucose homeostasis, all of which cause type 2 Key factors in the development of diabetes.
A systematic literature review and meta-analysis (including 17 randomized controlled studies involving 1529 menopausal women) pointed out that taking soy isoflavones can help improve fasting blood glucose, insulin resistance, and insulin sensitivity index, especially The effect of using genistein alone is the most significant.
The underlying mechanism is related to the fact that soybean isoflavones have alpha-glucosidase inhibitor, Tyrosine Kinase Inhibitor, regulate PPAR pathway and activate alpha 1 adrenergic receptor.
*Conclusion: For menopausal women, supplementation with soy isoflavones has a positive effect on blood sugar control, but due to the heterogeneity of the included studies, more large-scale trials are still needed to corroborate.
6. Soy isoflavones reduce the incidence of breast cancer
Breast cancer is the most common cancer of women in the world (after cervical cancer). By 2030, the global breast cancer burden will increase to more than 2 million new cases each year.
Uncontrollable risk factors associated with breast cancer are gender, age, genetics, family history, personal breast cancer history, dense breast tissue, menstrual cycle, previous breast radiation, and estrogen use.
Risk factors related to lifestyle include no history of pregnancy or late childbirth, use of birth control pills, non-breastfeeding, alcoholism, overweight, obesity, lack of exercise, and abortion.
A meta-analysis of literature (including 35 epidemiological studies) pointed out that for women in the pre-menopausal stage in Asia, the intake of soy isoflavones is associated with a lower risk of breast cancer.
However, for premenopausal women in Western countries, there is no evidence that soy isoflavone intake is related to breast cancer.
*Conclusion: Soy isoflavone intake is associated with lower breast cancer events (especially Asian women) but is limited by the heterogeneity and potential publication bias between studies, and randomized controlled trials are still required to prove its causal relationship.
7. Soy isoflavones are beneficial for blood pressure regulation
High blood pressure is a global public health problem. It may cause heart disease, stroke, kidney failure, blindness, rupture of blood vessels, and cognitive impairment, especially for people over 50 years old. A systolic blood pressure of more than 140 mmHg is a more important cardiovascular disease risk Factor.
Taking 115/75mmHg (systolic blood pressure/diastolic blood pressure) as the benchmark, if the blood pressure increases by 20/10mmHg, the risk of cardiovascular disease will also double.
A systematic literature review and meta-analysis (including 14 randomized controlled trials, 789 participants) pointed out that compared with placebo, subjects with normal blood pressure and prehypertension supplemented with soybean isoflavone extract can significantly reduce contraction Pressure (-1.92 mmHg).
Subgroup analysis showed that the relevant improvement effect is particularly: the use of more than 3 months, Western population, low dose, low-risk prejudice is the most significant.
The underlying mechanism may be related to isoflavones increasing nitric oxide levels, which in turn improves vasodilation.
*Conclusion: Supplementing soybean isoflavone may have the effect of regulating blood pressure (systolic blood pressure), but it still needs to be further confirmed whether it can be applied to improve hypertension.
8. Soy isoflavones reduce the risk of prostate cancer
Prostate cancer is the second most common cancer among men after lung cancer. It is estimated that there are more than 1.1 million new cases and more than 307,000 deaths worldwide each year.
In North America, the incidence of prostate cancer is 10 times that of Asia. Although these regional differences may be affected by ethnicity (genetic factors) and early diagnosis, evidence suggests that environmental and dietary factors may also play an important role in the occurrence of prostate cancer.
A systematic literature review and meta-analysis (including 8 randomized controlled trials) pointed out that for subjects with potential prostate cancer risk, ingesting soy products or soy isoflavone supplements can help reduce the risk of prostate cancer. Up to 51%).
However, there was no significant change in the level of prostate-specific antigen (PSA), sex hormone-binding globulin, testosterone, free testosterone, estradiol and dihydrotestosterone.
The underlying mechanism may be related to the regulation of cell proliferation, cell cycle, apoptosis, tumor angiogenesis, tumor cell invasion and metastasis possessed by soybean isoflavones.
*Conclusion: Taking soy isoflavones or soy-related products can help reduce the risk of prostate cancer, but considering the limitations of sample size and study time, more long-term large-scale clinical trials are still to be further verified.
9. Soy isoflavones help to lose weight (for menopausal women)
In addition to causing various discomforts, hormonal fluctuations in menopause also cause changes in body fat accumulation sites, greatly increasing the risk of overweight and obesity, and increasing the incidence of insulin resistance, type 2 diabetes, and cardiovascular disease.
According to reports, compared with women before menopause, women’s abdominal and subcutaneous fat will increase by 49% and 22% respectively during menopause.
A meta-analysis (30 studies, about 2800 non-Asian postmenopausal women) pointed out that soy isoflavone supplementation can have positive effects on weight loss, blood sugar, and insulin control compared to the placebo control group effect.
The related weight loss effect is especially significant for subjects with a body mass index of less than 30, a dose of less than 100 mg, and a period of use not exceeding 6 months.
*Conclusion: Non-Asian women after menopause supplementing with soy isoflavone can produce weight loss, but more research is still needed to confirm whether they have the same effect on Asian ethnic groups
Are there any side effects of soy isoflavones?
Soy isoflavones are part of the soybean diet and have been consumed by humans for many years. They have high safety, but possible side effects or adverse reactions include gastrointestinal upset and nausea.
Serious allergies to soybean-related products are rare. However, if any possible symptoms appear after consumption, including skin rash, itching/swelling (especially the face, tongue, and throat), severe dizziness, and difficulty breathing, seek medical assistance immediately.
1. A study of the elderly found that taking 100 mg of soy isoflavones daily for 6 months showed good tolerance.
2. In vitro and animal studies indicate that for subjects with insufficient thyroid function or insufficient iodine intake, ingesting pulses may increase the risk of clinical hypothyroidism.
3. Do not use for pregnant women and lactating women (because the relevant safety is unknown).
4. Although studies suggest that soy isoflavones can reduce the incidence and recurrence rate of breast cancer, women with a history of breast cancer, especially those with estrogen receptor-positive (ER+) breast cancer, should not increase phytoestrogens significantly Ingestion, including soy isoflavones.
5. Although some studies believe that long-term high-dose soy isoflavones may stimulate endometrial hyperplasia, and endometrial hyperplasia may be related to endometrial cancer, but this argument has not yet been confirmed.
6. Do not use if you have been allergic to soybean products, it may cause allergic reactions.
7. Because isoflavone metabolism is related to intestinal bacteria, antibiotic treatment may reduce the bioavailability of isoflavones.
Where to buy soybean isoflavone capsules recommended by most people?
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