A study from Washington State University demonstrates that exposure to the herbicide/pestice, glyphosate, causes genetic changes that leads to increased rates of disease in subsequent generations. 

Sperm of male rats exposed to glyphosate underwent genetic changes that were associated with higher rates of diseases three generations later (the equivalent of the rats’ great-children). 

This provides evidence that “glyphosate-induced changes to sperm from exposed rats could be used as biomarkers for determining propensity in subsequent generations for prostate and kidney diseases as well as obesity and incurring multiple diseases at once,” reads the study summary. 

Approximately 90% of the third- and fourth-generation rats who were related to the experiment group, by the time they reached middle-age, developed one or more of the aforementioned health problems. This rate was “dramatically higher” than the control group.

The evidence does not show causation in humans. However, the study provides “a proof of concept.” Approximately 50 rats were used in each generational group. 

The study was published in the journal Epigenetics on Dec. 9, and echoes the results of a similar study on mice, conducted last year by the same lead scientist, Michael Skinner, a professor of biological science. In the study on mice, Skinner’s team demonstrated that after mice were exposed to glyphosate, they passed on a higher rate of disease to subsequent generations.  

Skinner said in a press release, “While we can’t fix what’s wrong in the individual who is exposed, we can potentially use this to diagnose if someone has a higher chance of getting kidney or prostate disease later in life, and then prescribe a therapeutic or lifestyle change to help mitigate or prevent the disease.” 

The US Environmental Protection Agency maintains that glyphosate is safe for humans. This is partly based on research that shows low toxicology in humans; glyphosate has a short half-life and breaks down in the body quickly. 

However, due to its ubiquitous nature in the US food supply, there is concern that glyphosate accumulates in the body to the extent that it can lead to health problems. Skinner’s research and other animal studies, the press release claims, “have provided evidence that health effects from glyphosate and other chemicals can be inherited by subsequent generations.”

In regards to inter-generational toxicity accumulation, Skinner, in the press release said, “Today worldwide, we only assess direct exposure toxicology; we don’t consider subsequent generational toxicity. We do have some responsibility to our future generations.”

One barrier preventing research on humans is, “It’s very difficult to find a population that is not exposed to glyphosate to have a control group for comparison,” Skinner said.