Male fertility in Vietnam Veterans: the effect of environmental toxins

In April, Legacy began to back cutting-edge research projects that study male fertility. (Read our announcement on COVID-related research here). As a discipline, male fertility offers more questions than answers today. It remains underfunded. We felt we had a responsibility to bridge this gap and bring better understanding about fertility to men.

One project we backed studied the effect that environmental toxins had on the sperm of Vietnam war veterans.

Men who go to war are likely to postpone having children with their partner. Nevertheless, they think about the legacy they want to leave behind as husbands, citizens, and fathers. A study of the effects war had on their fertility, to us, was important.

Dr. Jamaji Nwanaji-Enwerem, the project’s principal investigator

The research study was led by Jamaji Nwanaji-Enwerem. Dr. Nwanaji-Enwerem holds a PhD from Harvard T.H. Chan School of Public Health/Harvard Graduate School of Arts and Sciences. He is also a final-year MD and Masters in Public Policy candidate at Harvard Medical School and Harvard Kennedy School, and a Soros Fellow. An immigrant from Nigeria, Dr. Nwanaji-Enwerem has authored over 24 environmental health publications in the last four years, and earned grants from reputable bodies like the National Institute on Aging and the International Society of Exposure Science. We feel privileged to have been able to support him in his research.

Dr. Nwanaji-Enwerem’s paper on male fertility — “Serum dioxin levels and sperm DNA methylation age: Findings in Vietnam war veterans exposed to Agent Orange” — was accepted into Reproductive Toxicology. (You can read it here.)

His team demonstrated that the presence of dioxins is associated with the increased methylation aging of sperm.

Why does this matter?

Dioxins are highly toxic, persistent, and organic pollutants linked to broad short-term and long-term health effects. The 37 Air Force veterans who participated in the study and produced sperm samples had all been exposed to concentrations of Agent Orange in the Vietnam War.

Methylation aging — or epigenetic clocking — has been shown to be a strong predictor of numerous diseases, mortality, and even offspring health. By discovering this link, Dr. Nwanaji-Enwerem helps to further quantify the negative impact of environmental toxins on sperm health. His team concluded by proposing that sperm methylation age measures may ultimately become a tool in a physician’s toolkit to appropriately assess the impact that environmental exposures may have on individual male reproductive outcomes.

There’s much more work to be done before we understand the probability of reproductive outcomes. But we look forward to the day when we do. Thanks for your work in pushing us forward and closer to that knowledge, Dr. Nwanaji-Enwerem.

-Khaled & the Legacy team
www.givelegacy.com