If Sherlock Holmes was a real person, would he be able to solve the mysterious case of chemical exposure and prostate cancer? Specifically, I’m talking about the chemicals used in products that kill bugs. Can you see where I’m going with this? If some chemicals are harmful to living cells in insects, might they also be harmful to human cells like those found in the prostate gland? In short, do pesticides (kill pests) cause prostate cancer (PCa)? Many consider this a great mystery.

Pesticides are widely used in agriculture. America is a huge nation, and feeding all of us is big business. Whether your diet includes meat, or you choose to be a vegetarian, we can’t exist without growing crops. After all, food animals are crop-consumers before they become hamburgers or chicken nuggets. According to one figure, without pesticides we would lose about 30% of our agricultural production to the insects that enjoy munching them.^[i] But the mystery remains: do pesticides cause PCa?

Step aside, Sherlock. Rather than pose that question to a fictional detective, a team of Stanford University researchers tackled it. Now, there are lots of different scientific experiments that could be done to show that chemical molecules are bad for prostate cells. You can expose cells in a petri dish to toxic substances. Or, you can test various chemicals by serving lab mice their food laced with particular pesticides and seeing if they develop PCa. And so on. In fact, many such experiments have been done, and their use has already established a link between pesticide chemicals and many diseases, including PCa. However, prostate cancer takes a long time to develop, so trying to establish a causal link between something a person was exposed to 15 years earlier and the onset of the disease is very difficult. You could hardly ask a group of human volunteers to eat food containing known toxic substances for 15 years and then track them to see how many develop PCa, compared to a similar group who eat organic food during the same period.

Therefore, the Stanford team took a different approach to solve the mystery using real human beings. Rather than work in a laboratory, they analyzed statistical patterns for two different time periods spanning 15+years in more than 3000 U.S. counties. In each county they calculated average pesticide by-crop use rates and applied them to the harvested acreage of each crop. They considered occupational pesticide exposure sources as applicators, etc. Their goal was to connect prostate cancer incidence (for example, how many PCa cases or deaths out of every 100,000 people in this county) and occupational exposure to any of 295 crop-use pesticides potentially linked to PCa in other studies.^[ii]

Findings

Out of the 295 toxic chemicals, the Stanford team identified 22 that were associated with PCa, including four that were linked at the county level with death from PCa. They established that these results were not attributable to other causes, since they corrected for factors such as “race, poverty levels, population density, agricultural product types, machinery utilization, farm valuation, and more.”^[iii]

By linking PCa to pesticide use, the authors are not calling for an end to these chemicals, since they have an important upside in terms of food production. On the other hand, educating consumers on better safety—and manufacturers who can look for alternatives that are deadly to insects but kinder to humans—can reduce the incidence of PCa cases likely arising from this particular risk factor. Also, identifying patterns of occurrence underscores that PCa is not randomly distributed across the entire U.S. map. If it were, a color-coded map would be uniformly all one hue, but this is not the case (see the CDC incidence map).

We have posted several blogs on occupations that appear linked with higher PCa rates: white collar jobs, transportation work, firefighting, and other higher risk lines of work. You may be surprised to learn that sedentary careers where you spend long hours sitting at a desk also increased PCa risk.

Agriculture is a noble profession. Our menfolk who farm their fields are feeding our nation. It is sad to think they may unwittingly be paying a price in terms of their health. By bringing this Stanford study to everyone’s attention, it is our hope that this knowledge is empowering—for both users and manufacturers—to implement better safety measures and continue to innovate less “human toxic” ways to prevent insect-caused crop destruction.

NOTE: This content is solely for purposes of information and does not substitute for diagnostic or medical advice. Talk to your doctor if you are experiencing pelvic pain, or have any other health concerns or questions of a personal medical nature.

References

[i] Wilson, F. Perry. “The Mysterious Link Between Pesticides and Prostate Cancer.” Medscape, Nov. 12, 2024. https://www.medscape.com/viewarticle/mysterious-link-between-pesticides-and-prostate-cancer-2024a1000k4r
[ii] Soerensen SJC, Lim DS, Montez-Rath ME, et al. Pesticides and prostate cancer incidence and mortality: an environment-wide association study. Cancer. 2024; 1-9. doi:10.1002/cncr.35572
[iii] Wilson, ibid.