Recent news reports have focused on health damage to users of a supplement made from the root of a Thai plant with properties similar to the female hormone estrogen. The Mainichi Shimbun answers some common questions readers may have about this supplement.
Question: There was news about an herbal supplement from Thailand that was making people sick, wasn't there?
Answer: Yes, Pueraria mirifica. It's a flowering vine in the Fabaceae -- or the legume -- family. The powdered roots of the plant are sold as a health supplement.
Q: What health benefits does the powdered root have?
A: The roots of Pueraria mirifica contain a chemical that is similar to the female hormone estrogen. In Thailand, the supplement is apparently mainly used as a folk remedy for menopause. However, in Japan it is claimed to increase breast size and aid in weight loss, among other things.
Q: What's the problem with it?
A: The estrogen-like effects of the plant are fairly powerful. Plants like soy beans also contain isoflavones, which also act similarly to estrogen. However, the effects of Pueraria mirifica is said to be roughly 1,000 to 10,000 times stronger than isoflavones.
Q: Is it really that strong?
A: It appears to be the case. The root seems to have a certain effect on increasing breast size, but if too much is ingested, irregular menstruation, abnormal bleeding, swelling of the uterine lining and other conditions could occur. According to the National Consumer Affairs Center of Japan, there were 209 complaints of health problems from the supplement in approximately five years starting in fiscal 2012. A National Institute of Health and Nutrition survey also reported cases of symptoms such as rash and vomiting as well as menstrual disorders.
Q: Is it really OK to sell this supplement?
A: As it is not a pharmaceutical product, there are no restrictions placed on it in Japan, and it can be found in the health food section of drugstores and similar shops. Since there is not enough data available about Pueraria mirifica, the European Union (EU) has not authorized it for sale as a food item.
"Even health supplements made from natural ingredients that have determinate positive effects can also have unwanted side effects," said Yoichi Nagamura, the head of the Japanese Association of Food Science and Risk Analysis. "However, this supplement goes beyond the category of food product, and one should refrain from ingesting it for the time being."
The Ministry of Health, Labor and Welfare is also in the process of investigating Pueraria mirifica, and is expected to release a cautionary notice in the near future. (Answers by Masami Kojima, Lifestyle News Department)