On Thursday, Oct. 21, Shanna H. Swan, Ph.D., one of the world’s leading environmental and reproductive epidemiologists and Professor of Environmental Medicine and Public Health at the Icahn School of Medicine at Mount Sinai in New York City, joined the Vail Symposium for a discussion about the precipitous decline in fertility over the past four decades.
- Dr. Swan was first made aware of the concerns regarding the drop in sperm count beginning in the 1990s. Her subsequent research not only confirmed those early findings, but also found that the problem has worsened in the intervening years.
- Sperm counts have declined by more than one percent a year for the past 40 years.
- This decline is not limited to Western countries, however that is where the most comprehensive data is found.
- As for the causes, genetics has been eliminated because changes on this scale are simply not possible within the span of two generations. Lifestyle factors are a consideration including poor diet, stress, binge drinking, heat (such as sauna), obesity, and sedentary lifestyle. These factors, taken alone or in combination, are ubiquitous in modern society. Chemical exposure, such as “hormone hackers” also known as endocrine disruptors, as well as pesticides and flame retardants are similarly everywhere. Water bottles, cosmetics, toys, pizza boxes, and the lining of tin cans all contain these detrimental chemicals.
- Phthalates make plastics soft and pliable. They have been shown to interfere with male reproductive function.
A fetus initially possesses undifferentiated sex organs. Male fetuses are bathed in testosterone at a very specific and limited point in fetal development. Any interference with this may result in smaller or malformed testicles, undescended testicles, and a shortened anal-genital distance (AGD). Males with a shortened AGD have more birth defects and incomplete descent of the testicles. The male programming window (MPW) occurs during the first trimester. - It is not only the pregnant female that must be concerned about environmental factors affecting the fetus. Smoking affects sperm. And a father who smokes will negatively impact his son’s sperm count.
Low sperm count is a harbinger of other health problems such as early death, heart disease, diabetes, and obesity.
Despite the dire information, Dr. Swan did offer suggestions to mitigate chemical exposure–remove hormonally active, endocrine disrupting chemicals, replace them with benign chemicals, and better regulation of these chemicals. - This will take political will.
- On a personal level she suggested buying organic, unprocessed foods. Eating a Mediterranean-style diet. Eliminating plastics from the household. And never microwave food in plastics.
