A new study by the University of Adelaide suggests that an increase in female hormones might be the reason behind obesity and infertility in men from the West.
Researchers say that exposure to estrogen might be increasing the male obesity rates. Exposure to common substances like soy products and plastics, which contain the female sex hormone, is making Western men fat.
For the study, the researchers compared the Gross Domestic Product and obesity rates among men and women worldwide. They noted that it was normal for women in developing countries to have significantly higher rates of obesity, the findings revealed little difference between sex and obesity in the western world.
"Hormonally driven weight gain occurs more significantly in females than in males, and this is very clear when we look at the rates of obesity in the developing world," researcher James Grantham said in a press release.
"However, in the Western world, such as in the United States, Europe and Australia, the rates of obesity between men and women are much closer. In some Western nations, male obesity is greater than female obesity," he added. Grantham said that there is more to than simply a high caloric intake for growing rates of obesity in men.
Researchers explain that estrogen exposure is known for weight gain, primarily through thyroid inhibition and modulation of the hypothalamus. Soy products contain xenoestrogens, and societies with a high dietary saturation of soy, such as the United States, might be working to 'feminize' the males, the researchers said. "This would allow men in those communities to artificially imitate the female pattern of weight gain," said co-author Professor Maciej Henneberg, a Wood Jones Professor of Anthropological and Comparative Anatomy.
He said that another rich source of xenoestrogen is polyvinyl chloride, known as PVC. This product is commonly used in most wealthy countries, from plastic medical devices to piping for our water supplies.
According to the researchers, the study findings could explain why western men have significantly lower sperm counts than those living in developed nations.
The findings were published in the online journal PLOS ONE.
