Sep 11, 2021 09:00:00

Is the theory that 'eating soy foods causes even men to swell their boobs' is true?

In Japan, there is an expression 'herbivorous ' that refers to a man who is light-hearted in love, but in English there is a similar expression 'Soy Boy ' that refers to a man who is not masculine. Professor William Helferich of the Department of Nutrition, University of Illinois explains from a scientific point of view the theory that 'eating Soy (soybeans) makes the body feminized', which is said to be the origin of this expression.

Does soy give men breasts? Science debunks a sexist myth about a popular food
https://www.inverse.com/science/does-soy-give-men-breasts-science-debunks

According to Professor Helferich, Men's Health, a lifestyle magazine for men, was the first to report that 'eating soybeans makes your body feminized.' An article reported by Men's Health in 2009 was finally reported by a former U.S. Army intelligence man who continued to drink 3 quarts (about 2.8 liters) of soy milk a day because he was lactose intolerant and couldn't drink milk. In an episode of being diagnosed with feminized lactose, in which the mammary gland tissue is enlarged despite being a man, the article at the time states that 'soybeans have a hidden dark side.'

Soy's Negative Effects | Men's Health
https://web.archive.org/web/20101105114313/http://www.menshealth.com/nutrition/soys-negative-effects

In this article, isoflavones contained in soymilk were mentioned as the true identity of the enlarged mammary gland tissue in men. According to Professor Helferich, isoflavones play the same role as estrogen (female hormone) in the human body inside plants, and when humans actually ingest isoflavones, the amount of estrogen produced changes. It is said that the case of 'acting on' has been confirmed.

However, according to a 2010 study by Mark Messina, director of the Soy Nutrition Institute , and a 2010 meta-analysis study that comprehensively analyzed 32 papers on the effects of soy on the human body, more than Americans and Europeans. Isoflavones do not have a feminine effect at intakes equal to or higher than the average intakes in Japan, South Korea, and China, which consume a lot of soybeans. '

As mentioned above, in recent years, 'soy milk makes men feminine' is considered to be a hoax, while the theory that 'soybeans affect breast cancer' is controversial. Was announced in the 2001 paper was published in and the 2009 paper in, is a kind of isoflavone found specifically in soy genistein , but is content that the results were obtained that increase the risk of breast cancer, 2017 A large follow-up study conducted in Japan concluded that women with breast cancer who consume high amounts of soybeans have a risk of death of up to 21% over 9 years.

It seems that the pros and cons of this are still ongoing, but the National Cancer Center in Japan has about 2 women aged 40 to 69 who lived in 10 health centers in Japan in 1990 and 1993. From the results of a survey that followed 15,000 people up to 2002, it was concluded that 'the risk of breast cancer is low in the group with high genistein concentration', and while admitting that there is a result that the risk of breast cancer is increased in animal experiments, 'from the diet' It has been suggested that if it can be taken, it may reduce the risk of breast cancer. '

Relationship between blood isoflavone concentration and breast cancer morbidity | Results to date | Multipurpose cohort study | National Cancer Research Center Social and Health Research Center Prevention Research Group
https://epi.ncc.go.jp/jphc/outcome/315.html