Fathers’ Exposures Matter Too!

Supporting the health and safety of a mother before and during pregnancy has become a cultural expectation, but new research shows a father’s health and safety may too have severe and lasting effects. 

For some time it has been known that exposure to phthalates, a class of endocrine disrupting chemicals (EDC), has led to a significant reduction in male fertility. A recent study from March 2020 explains how exposure to the phthalate, di-2-ethylhexyl phthalate (DEHP), can lead to lower sperm count and reduced sperm mobility AND how exposure to DEHP can be passed down to future generations leading to reproductive abnormalities without those babies ever being exposed to DEHP themselves (Barakat et al, 2020). 

So what are phthalates and how are we being exposed? Phthalates are a class of chemicals used in a wide variety of products – from fragrance to cleaning supplies. There are also found in our foods, often from use as plasticizers in food packaging or dairy tubing. Its primary use is to soften plastics to make them flexible. When phthalates are added to plastics, they do not chemically bind tightly. This is a problem because the phthalates leave their original container and migrate either into food or water, then into our bodies through ingestion, or directly into us via dermal absorption through the skin. 

DEHP, specifically, is on the Proposition 65 list because it can cause cancer and birth defects or other reproductive harm. While we know exposure can affect fertility in a male’s lifetime, this recent study found that exposure to DEHP may be passed down from father to son. Exposure during early development can physically and permanently alter the epigenome, or your DNA, and cause these changes in the DNA to be passed down from one generation to the next, through a process called epigenetic modification. They found the effects are linked to the Y chromosome, which is specific to males and passed down from father to son. The research showed that DEHP exposure before birth causes accelerated reproductive aging, a decrease in testosterone production, and an overall decline in sperm quality. Babies born from a father who was exposed to this endocrine disruptor had a severe decrease in sperm count, mobility, and quality even if they were never exposed to DEHP themselves. This provides evidence that the Y chromosome carries the effects of the exposure from DEHP to future generations. 

What can we do with this information? The most effective next step is to look for safer alternatives in order to reduce exposure to phthalates. Try to keep food and beverages in glass containers and choose a safer alternative to plastic wrap like beeswax wrap. Whenever possible, reduce the use of plastics with a #3 on the bottom of the container in the recycling symbol because these plastics often contain phthalates. Choosing safer alternatives today can help protect our future generations.

Sources: 

Barakat, R., Lin, P., Park, C.J. et al. Germline-dependent transmission of male reproductive traits induced by an endocrine disruptor, di-2-ethylhexyl phthalate, in future generations. Sci Rep 10, 5705 (2020). https://doi.org/10.1038/s41598-020-62584-w