What are the Soy Isoflavones Side Effects?

Note: This post contains affiliate links and I may be compensated if you click on them.

Isoflavones are estrogen-like compounds (phytoestrogens) that are naturally derived from plants. The most popular sources of isoflavones are soy beans and soy products. According to the American Heart Association, intake of soy to about 25 grams a day has a lot of healthful benefits such as prevention of hormone-related cancer and heart diseases. On the darker side, there are known side effects associated with intake of soy isoflavones. What are the soy isoflavones side effects?

A study was done by the Department of Nutrition of Arizona University in the use of soy isoflavones as hormone replacement therapy for post menopausal women. The study revealed that there are cases where women experienced elevated blood pressure to a point of hypertensive crisis.

Soy isoflavones are naturally from a bean thus gastrointestinal side effects are likely to be experienced. Some digestive side effects are bloating, gas formation, cramping, constipation, and even diarrhea. There are cases where food allergies are triggered with the intake of soy isoflavones supplements. Symptoms associated with food allergies are itching, stomach irritations and runny nose.

A research at Weston A. prince foundation revealed that there is a direct correlation between intake of soy isoflavones and thyroid diseases. Soy isoflavones were thought to interfere with thyroid hormone synthesis and cause goiter and hypothyroidism. Thyroid diseases can actually be prevented with the intake of iodine. Commercial producers of soy products are required to add iodine in their products so to counteract its effect in the thyroid gland. In addition, high doses of soy supplements were found to cause thyroid cancer.

Pregnant women are not advised to consume high level of soy isoflavones because of the increased risk of birth defects especially for male babies. Soy isoflavones can lead to male babies with hypospadias wherein the urinary opening is below the normal position. Also, soy isoflavones could to babies with low bone density.

One study at the Linus Pauling Institute say that soy isoflavones increases the production of estrogen receptor breast cancer cells. It could also interfere with some chemotherapeutic agents such as tamoxifen. With this, women with breast cancer are advised to have moderate intake of soy products.

There are a number of people who testified that they experience head ache after consuming products with isoflavones. For those with allergic reactions to soy products, headache may be experienced as a result of palpitations or increased in heart rate.

These are some of the side effects of taking in soy isoflavones. It should be emphasized that intake of soy isoflavones is not bad for the health but excessive intake of which is. So, when thinking about soy supplements, better talk to your doctor for the appropriate dosage so to prevent thyroid problems and worse, cancer.