Reproductive System in Male Mice Disrupted by Chemicals

Researchers have repeatedly demonstrated that prenatal exposure to diethylhexyl phthalate damages the reproductive system of male mice and leads to fertility problems. In one study, scientists at the University of Illinois Urbana-Champaign showed that the combination of DEHP and a high-fat diet in pregnant mice can cause more damage to the young than either factor alone.

How Exposure to Certain Chemicals Affects the Reproductive System of Babies

Reproductive disorders in men are a growing problem due to the global decline in sperm count and quality. Alarmingly, chemicals such as DEHP, which are found in food containers, medicines, and building materials, have been identified as one of the contributing factors. The toxicity of DEHP stems from its ability to mimic hormones in our bodies, leading to long-term health effects. “The scientific community is aware of the fact that the current generation of men produces only half as many sperm as the previous generation,” said CheMyong Jay Ko (EIRH), professor of veterinary medicine. “Although this is shocking, not much attention is being paid to understanding the causes.”

The researchers used the Barker hypothesis as a guiding principle for their study. This hypothesis was proposed by British physician and epidemiologist David Barker and states that the nine months in the womb are one of the most critical periods in a person’s life and can influence their future health. “The Barker hypothesis focuses primarily on nutrition, and we wanted to test whether the mother’s diet can affect the health of the next generation,” Ko said. “In addition, unlike the previous generation, we are constantly exposed to chemicals such as DEHP that can alter the way our bodies function. We wanted to find out whether exposure to these two factors can cause the reproductive system of developing babies to develop less well.”

In the past, both the Ko lab and other research groups have shown that prenatal exposure to DEHP lowers testosterone levels and causes fertility problems in male mice. In addition, scientists have shown that a high-fat diet in the mother can also lead to a reduction in sperm count in male offspring. However, the effects of both factors together had not yet been studied.

Fewer Sperm, Lower Testosterone Levels

The researchers used four groups of pregnant mice; one served as a control group, while the other three were exposed to either DEHP, a high-fat diet, or a combination of both. They then observed each litter, which consisted of an average of 6 male and 6 female offspring. Surprisingly, they found that a high-fat diet had a more harmful effect on the male reproductive system than DEHP alone, and that the offspring of mothers who had been treated with both had the worst results.

The researchers measured the body weight and various reproductive organs of the offspring at different stages of growth and puberty. They found that although the body weight of the offspring whose mothers received a high-fat diet alone or in combination with DEHP was higher than that of the other offspring, the weight of their reproductive organs was lower. They also found that these mice produced less sperm and had lower testosterone levels. By staining the tissue, the researchers found that the reproductive organs had abnormal cells that contributed to the dysfunction of the gonads. “We used these mice as a model in our studies. Although we still need to confirm these results in humans, this study should serve as a warning to our generation that we need to pay attention to our environment and diet during pregnancy,” Ko said.