Over the past six to seven decades, there has been a drastic reduction in male sperm counts throughout the world. In 1990, researchers discovered a decrease in sperm count and a loss in seminal fluid volume. By the 2010s, it became apparent that a steady decline in sperm count had been taking place, and a 2017 study even noted a drastic 50+ percent decrease over the period between 1973 and 2011 in both sperm count and fluid volume.

In February 2020, a study published in JAMA Network Open (an open access medical journal) concluded that men who consumed a typical “Western diet” appeared to have lower sperm counts. The so-called Western diet utilized in the study was composed predominantly of red meat, fried foods, and soft drinks, and its consumers had an average sperm count between 109 and 138 million per sample. It was compared to an example of a “generally healthy” diet, with a count ranging between 146 and 183 million. This study is supported by an article from the University of Chicago in 2018, which added obesity as a factor for lower sperm quality, in addition to unhealthy food. The decreased nutritional value of the average diets of people around the world, especially Americans, has contributed to a drastic decrease in sperm quality.

In addition to poor nutrition intake, researchers at Rutgers and Columbia have confirmed a correlation between stress and low sperm counts. Results found that, in instances of prolonged stress, there was an average of a 47% decrease in sperm motility. Other studies found similar results, with the National Institutes of Health describing a 39% decrease in sperm concentration during a period of stress compared to an average 48% decrease in motility. While there are methods to release stress, including the aforementioned healthy eating, a clear societal shift has occurred in the past several decades to increase stress levels across the working population. This “workaholic” societal attitude has led to many problems, including this health issue.

This crisis has recently become especially newsworthy as a result of a series of articles describing how certain chemicals, which have seen more use in the last few decades, have an effect on sperm counts. In their book, Count Down: How Our Modern World Is Threatening Sperm Counts, Altering Male and Female Reproductive Development, and Imperiling the Future of the Human Race, authors Stacey Colino and Shanna Swan argue that chemicals that have only recently become pervasive in our world interfere with our hormones and contribute to harmful reproductive health outcomes.  Described as “endocrine-disrupting chemicals,” these chemicals include phthalates (used in a wide variety of plastics to make them more flexible) and bisphenol A (BPA), among those that are water-soluble and wash out of the human body. However, the list also includes “forever chemicals” such as perfluoroalkyl substances, which are used in a variety of industrial processes. The surging use of these chemicals in the last few decades correlates with the decrease in sperm counts around the world. As a result of a variety of factors which have changed in our society, humans have suffered the adverse effects of lessened reproductive health.