Pesticides Reduce Sperm Counts, Study Suggests

A meta-analysis of 20 studies found that men with higher exposure to commonly used pesticides had lower sperm concentrations.

Over the past 50 years, sperm counts have declined by around 50%. Yet, scientists aren't exactly sure why this is happening. Though some suggest cell phone use may play a role, nutrition, lifestyle factors, and exposure to endocrine-disrupting chemicals could also be factors.

Now, scientists suspect that pesticides may impact sperm.

For example, earlier research found pesticides affect the male reproductive system by reducing sperm density, inhibiting sperm development, and lowering sperm motility.

To examine this more closely, researchers from the George Mason University College of Public Health in Washington, D.C., and Northeastern University in Boston, Massachusetts, conducted a systematic review and meta-analysis of 20 studies involving 1,774 adult men. Their results were published on November 15 in Environmental Health Perspectives.

The researchers looked for associations between sperm concentrations and exposure to organophosphates and N-methyl carbamates — two commonly used pesticides.

They found that higher exposure to these chemicals was linked to lower sperm concentrations, especially for men who encounter pesticides on the job.

Moreover, a separate analysis found that organophosphates may pose a greater risk to sperm concentration than N-methyl carbamates.

In a George Mason University press release, Lauren Ellis, MPH, a doctoral student at Northeastern University, said, "Understanding how insecticides affect sperm concentration in humans is critical given their ubiquity in the environment and documented reproductive hazards. Insecticides are a concern for public health and all men, who are exposed primarily through the consumption of contaminated food and water."

Still, the study's authors say that because of gaps in the research, they cannot say for certain these chemicals directly cause low sperm counts, and further research is needed to establish a causal relationship.

The paper's senior author, Melissa J. Perry, Sc.D., MHS, dean of the George Mason University College of Public Health, concludes, "This review is the most comprehensive evidence sizing up more than 25 years of research on male fertility and reproductive health. The evidence available has reached a point that we must take regulatory action to reduce insecticide exposure."

What can men do to boost sperm counts?

In light of this latest study, one of the first things a man could consider is reducing exposure to organophosphates, N-methyl carbamates, and other pesticides. Moreover, previous research suggests that avoiding endocrine-disrupting chemicals — which can affect hormone function and sperm quality — may be important.

Other changes include getting enough exercise and eating a healthy diet with plenty of antioxidants.

Vitamin C, vitamin D, zinc, and folic acid may also help improve sperm health, while herbs such as fenugreek and ashwagandha root might boost testosterone levels and sperm quality.

In addition, wearing tight clothing or taking hot baths can impact sperm counts because the testicles need to be slightly cooler than a person's core body temperature for optimal sperm production.

Still, men concerned they might have a low sperm count should contact their healthcare provider before starting any supplements or a new diet or exercise program. If warranted, a doctor can order a semen analysis to determine whether sperm quality needs improvement.