Here is a chart of agricultural chemical (like pesticides) use by country, compared to testosterone in that country. There seems to be a strong relationship! Testosterone is much lower in the countries that use a lot of agricultural chemicals.
This might help explain the very severe and mysterious drop in testosterone in most but not all parts of the world since about 1980. The other connection I’ve identified is PUFA consumption from the rise in seed oils in people’s diets around the world.
Here’s a chart that shows that places in the USA with many cornfields nearby generally have low testosterone. The few places in the USA that have testosterone that isn’t too low, generally don’t have cornfields nearby.
Some of the locations on the map have many crop fields nearby, but testosterone wasn’t as low. Hay fields and wheat fields don’t correlate so well with low testosterone. But when we focused on cornfields or soybean fields we found this pretty strong correlation. We think that some of this may be the result of the pesticide atrazine, which is used mostly on corn and not so much on other crops. (Source)
Here is a map of testosterone in the USA. (Using the same data as the chart above) You can see that the corn-growing midwest is especially low.
You can start to protect yourself from pesticides lowering your testosterone by filtering your water. Pesticides get into water runoff from farm fields, and from there into the water supply. It’s probably worse if you live in an agricultural area.
There’s a comprehensive article on the best water filters to remove pesticides that lower testosterone at this website: https://whatwaterfilter.com/best-water-filter-removes-pesticides/
Another way that pesticides can get into your body is on your food. This organization does a great job identifying which fruits and vegetables have the worst levels of pesticides – https://www.ewg.org/foodnews/dirty-dozen.php
You should consider growing these plants on your own, or buying them from a farmer’s market or at least certified organic.
Russia, Central Asia, Pesticides, and Testosterone
Central Asia raises some questions about the link between pesticides and low testosterone. As far as I can tell from a quick look, the situation is as follows:
All regions of Central Asia studied had high testosterone a few decades ago. At this time, Kazakhstan grew grain, and the rest of Central Asia grew other products, but perhaps not as much since these places are more arid or mountainous.
In the current day, most of Central Asia has kept its high testosterone, but the studied regions of Kazakhstan now have very low testosterone.
Perhaps the low testosterone seen in Kazakhstan is due to the long term, multi-generational effects of pesticide exposure from grain production some decades ago, even though those people at the time had high testosterone.
According to this report, all Central Asian nations have areas heavily contaminated with pesticides. It would be a problem for our theory if the Central Asian nations other than Kazakhstan have just as high pesticide contamination as Kazakhstan. My guess is that wide areas of northern Kazakhstan are contaminated, while only localized parts of the other Central Asian nations are contaminated. But that is a guess that I haven’t confirmed yet.
Another big issue for the theory is that some parts of Russia with high grain production also have high testosterone, specifically Stavropol and Kurgan. It seems that the people in Stavropol could be exposed to much the same amount of wheat pesticide as the people in Kazakhstan, so why would they have such different hormone levels?
This area needs further study!
What else lowers testosterone?
Another potential cause of low testosterone is the seed oil found in junk food. We have an article about that here. And if you’re interested in snacks made without seed oil, check out our potato chips made with tallow, and no seed oil!
They’re available at https://noseedoil.com/chips and you can click the horse in the image to visit that page.