Dietary supplement manufacturers repeatedly advertise themhealing effectof soy and red clover isoflavones. They are said to help with various ailments and even protect against cancer or osteoporosis. But what is actually behind it and are the highly touted nutritional supplements really a cure? Due to a lack of data on the effect of isoflavones, doctors and pharmacists are cautious. We summarize the results of several studies and try to clarify whether and to what extent flavones have a positive effect on our health, what areas of application they have and what side effects have already been reported. One thing is certain: Before you take dietary supplements containing isoflavones, you must consult your family doctor. Only he can correctly determine the daily dose and assess any risks or side effects.
Isoflavone effect: What are phytoestrogens?
The isoflavones (also known as isoflavonoids) are dietary supplements that are produced exclusively by legumes. They are a specific group of molecules called phytocompounds (natural plant compounds) that are found inFoods like beansand can be found in herbs such as red clover. The isoflavones are called phytoestrogens because their structure is similar to the female hormone estrogen. They are also considered antioxidants because they reduce the damage caused by oxygen (the so-called free radicals). They help fight some types of cancer. There are many studies on the benefits and safety of isoflavones. However, researchers' opinions vary widely.
Soybeans have the highest isoflavone content among foods. The herbs red clover and alfalfa are also rich in isoflavones. Like soy, red clover is classified as a legume that contains phytoestrogens. The soy isoflavones are genistein, daidzein and glycetein. Red clover contains formononetin, biochanin A, daidzein, and genistein.
It is important to note that taking supplements is similar to consumingfoods (e.g. tofu, tempeh, soy milk or other soy products) cannot be equated as a source of isoflavones. They result in various benefits and side effects.
Isoflavone effects during menopause
DieEstrogens are hormones, which control sexual and reproductive development, especially in women. The similar structure allows isoflavones to bind with estrogen receptors. When hormone levels fluctuate, isoflavones can affect us in the same way as estrogen. Several studies on the use of isoflavone-containing supplements for menopausal symptoms report certain benefits, such as improvement in fatigue and irritability and reduction in hot flashes. Although isoflavones are marketed as an effective natural hormone replacement therapy (HRT) product, further studies are needed to demonstrate their safety and effectiveness, according to The Pharmaceutical Journal. Consumers should therefore not use them for long-term therapy.
Further areas of application of isoflavones
1. Additionally, isoflavones are claimed to prevent some types of cancer. However, researchers do not agree on this. People who consumed a lot of soy products in their youth may have a lower risk of breast cancer later in life. However, some studies report that soy isoflavones increase this risk.
2. Red clover has also been found useful in cardiac problems as it increases good cholesterol called HDL.
3. Isoflavonoids in red clover reduce hot flashes and depressive moods during menopause.
Medical use
The following symptoms can be alleviated through the use of isoflavonoids:
Diabetes Typ 2:The researchers report that consumption of soy proteins orfermented soy productslowers blood sugar in this type of diabetes.
Diarrhea in small children:Soy baby food can shorten the duration of diarrhea (compared to cow's milk baby food). Important: The soy fibers do NOT help adults.
High cholesterol:Clinical research has proven that soy isoflavonoids lower the bad cholesterol HDL. It is important that ONLY protein foods such as tofu, tempeh and other products lower cholesterol. Dietary supplements containing isoflavonoids are not effective.
High blood pressure:Eating soy may slightly lower blood pressure and is recommended for patients with mildly elevated blood pressure, but NOT for those with very high blood pressure.
Irritable bowel syndrome (IBS):The soy isoflavones can relieve symptoms of IBS, such as abdominal pain.
Symptoms of Menopause:Symptoms such as restlessness, depression and hot flashes can be relieved with the use of isoflavonoids. However, their effectiveness for night sweats has NOT been confirmed.
Osteoporosis:According to several studies, soy protein from foods and dietary supplements can increase bone density.
Which foods contain isoflavones?
Soy and red clover are among the most important suppliers of isoflavones. But they are also found in other foods. These include the following legumes:
- Chickpeas
- Broad beans
- Pistachios
- Peanuts
- Other legumes and fruits
Isoflavones in fermented soy products
In Asia, where soy is the main product consumed, rates of heart disease and breast and prostate cancer are lower than in the West. However, Asians consume soy in different ways. For example, you eat much larger amounts of soy every day. It is also common to use fermented soy products, including miso, tempeh and tamari. The world-wide popular soy sauce does not contain isoflavones. It is believed that fermentation aids digestion and promotes the processing of isoflavones. Many experts believe that moderate consumption of fermented soy products:
• increase bone density,
• prevent breast and uterine cancer,
• reduce prostate cancer rates,
• lower the level of bad cholesterol,
• improve mental function and
• Can relieve muscle pain.
In these cases, isoflavones are not effective
The effectiveness of isoflavonoids has NOT been proven for many complaints, e.g. B. at:
• Alzheimer
• Asthma
• Heart disease such as heart attack
• Colic in babies
• Crohn's disease
• Uterine cancer
• Stomach cancer
• Hepatitis C
• Prostate enlargement
• Prostate cancer
• Rheumatoid arthritis
• Thyroid cancer
• Kidney diseases
Isoflavone side effects
Most of the side effects of isoflavonoids are associated with long-term use. Epidemiological studies have found a link between long-term consumption of soy products and Kawasaki disease. Other studies show that using soy-based substitute foods in babies could affect later pubertal development. The growth of breast cancer cells is associated with a long-term influence of genistein. Research on animals has demonstrated a negative impact on the development of the reproductive system. If taken for a short period of time (up to 6 months), the soy food supplement is considered harmless.
Common side effects:
• Gastrointestinal inflammation (gastroenteritis)
• Constipation, flatulence and vomiting
• Allergic reactions (rash, itching and, in severe cases, shortness of breath)
• Appetitverlust
Isoflavones Contraindications:
- There is not enough information to support the safe use of soy products during pregnancy and breastfeeding, especially in high doses. Some studies link soy-based baby foods to developmental delays in young children. Children should not eat large amounts of soy products long-term.
- Asthmatics and people who suffer from hay fever are at higher risk of an allergic reaction.
- Patients with breast cancer should seek advice from their doctor because soy could act like estrogen and promote the growth of cancer cells.
- Children with cystic fibrosis should avoid taking isoflavonoids because they may interfere with the processing of proteins.
- People with diabetes should seek medical advice as soy products may lower blood sugar and interact with certain medications.
- The isoflavonoids could worsen hypothyroidism (underactive thyroid).
- People who suffer from kidney stones or kidney weakness should not take isoflavones. They promote the formation of oxalates and could be toxic to kidney patients.
- Patients should consult their doctor about the interaction of isoflavones and other dietary supplements with other medications. This also applies to their dosage and preparation. The isoflavonoids should not be taken for longer than 6 months.
- When buying, you should make sure that the products contain natural phytoestrogens in extract form. Choose non-genetically modified products.
Isoflavone effect: studies
There are currently not enough studies regarding the isoflavone effect. Nevertheless, there are several who have examined the positive and negative effects of isoflavones. We summarize the results for you:
In 2016, a study was carried out inBritish Journal of Pharmacologypublished. As part of this study, the researchers tested the positive effects of phytoestrogens. The scientists were unable to determine whether the positive or negative effects outweighed the negative ones.
A study also published in 2016Journal of the American Medical Associationwas published, summarized the results of 60 other studies. The result – isoflavones are said to provide moderate relief from symptoms such as hot flashes during menopause. However, they have proven ineffective against heavy sweating at night.
A study inJournal Nutrientswas published, points out the side effects of isoflavones. According to the authors, the isoflavones are intended to suppress the immune response. Phytoestrogens do have an anti-inflammatory effect. However, the extent to which they are used as adjunctive therapy still needs to be investigated.
In Germany, the Federal Institute for Risk Assessment recommends that red clover isoflavones be taken for a maximum of 3 months. Of course, in many cases a shorter duration makes sense. However, your family doctor can best assess this. Self-medication is definitely not recommended.
Isoflavone effect: conclusion
Isoflavones are being hailed as the new miracle cure. In fact, when dosed correctly, they can provide relief from some ailments. However, the side effects that short-term therapy with isoflavones could have have not yet been studied in detail. Therefore, isoflavones should only be taken after consulting a doctor. Not only because of the side effects and the dosage, but also because of the numerous contraindications. In individual cases, isoflavones can increase the growth of cancer cells in breast cancer patients. Allergy sufferers, asthmatics and diabetics should better look for another therapy. Even in otherwise healthy people, therapy with isoflavones should only be carried out for a short time. You should also seek advice from your family doctor about the possible benefits of a diet rich in isoflavones.
