Nearly 20 of the most common pesticides used in America are linked to prostate cancer, a study warns.
Researchers from Stanford University looked at exposure to 295 different types of chemicals across the country between 1997 and 2006.
Because cancer takes time to develop, the team then looked at cancer rates from 2011-2020 to see whether areas with high pesticide use also had high cancer rates.
They found that men exposed to 22 different pesticides were more likely to develop the disease than men who had less exposure to the chemicals, including 19 who had never before been linked to cancer.
Four of those pesticides were also linked to an increased risk of death from cancer. The study authors wrote that: ‘These findings suggest that pesticide exposure may contribute to variations in prostate cancer incidence and mortality.’
These are commonly used on some of the country’s most common crops, including soybeans, wheat, corn and oats. These crops can be found in everything from breakfast cereals to snack bars to plant-based milks.
More than 95 percent of samples of strawberries, apples, cherries, spinach, nectarines and grapes contained at least two pesticides, the EWG found
Your browser does not support iframes.
This adds to previous studies from the Environmental Working Group (EWG), which found that about 90 percent of strawberries, apples, cherries, spinach, nectarines and grapes tested positive for two pesticides.
However, much of the corn and grain grown in the US is not made directly for human consumption, but is instead processed into ethanol or used as feed for livestock.
The same EWG analysis actually found that sweet corn grown for human consumption is low in pesticides.
In 2023, 288,300 Americans were diagnosed with prostate cancer and 34,700 people died from the disease.
It is the second most common cancer in men in the US.
It affects the walnut-sized gland located at the base of the male bladder and which is important in sperm generation. About one in eight men will experience it at some point in their lives.
For years, prostate cancer has been linked to exposure to a number of different chemicals, including pesticides, according to John Hopkins.
Brain, kidney, lymph and blood cancers have also been linked to pesticides.
The Stanford study, published in the Journal of the American Cancer Society, Cancerlooked at county-level data on pesticide use, estimating the major types of chemicals people across the country were exposed to and at what levels.
They analyzed 295 of some of the most common pesticides over two different time periods, to check that the patterns they discovered weren’t just a one-off event.
First, they compared pesticide exposure from 1997 to 2001 with prostate cancer rates from 2011 to 2015.
There were 953,204 prostate cancer diagnoses and 140,086 deaths during this period.
Second, they compared pesticide exposure from 2002 to 2006 with prostate cancer rates from 2016 to 2020.
During this period there were 1,063,671 diagnoses and 156,687 deaths.
They found that 22 of the pesticides they examined were associated with a higher incidence of prostate cancer.
Lead author, urologist Dr Simon John Christoph Soerensen, said: ‘This study demonstrates the importance of studying environmental exposures, such as pesticide use, to potentially explain some of the geographical variation we observe in the incidence and prostate cancer deaths in the United States.”
Studies conducted by the EWG found that the pesticide glyphosate was present in grains in both 2018 and 2023. They note that the
Some of these pesticides, including 2,4-D, linuron and carbaryl, had already been linked to cancer in older studies.
The International Research Agency classifies 2,4-D as ‘possibly carcinogenic to humans’ and warns against inhaling or ingesting the chemical.
However, 19 other chemicals, used to control weeds, insects, fungi and other pests, had never before been linked to prostate cancer, the authors report.
Some of these include cloransulam-methyl, a herbicide used on soybeans and Thiamethoxam, an insecticide sprayed on the seeds of corn, cotton, soybeans, wheat and potatoes, and glyphosate, a weedkiller found in RoundUp.
Four pesticides were also linked to an increased risk of death from prostate cancer, including rifluralin, cloransulam-methyl, diflufenzopyr and thiamethoxam.
An analysis by DailyMail.com found that 14 of the 22 chemicals identified by the Stanford study are used on soybeans, 13 on corn, 10 on wheat, 10 on oats and 8 on almonds.
However, this does not mean that all these products are always consumed by people.
According to the American newspaper, less than 2 percent of corn grown in the US was intended for human consumption in 2020 World Resources Institute– with the majority focused on making ethanol and animal feed.
Only about 15 percent of U.S. soybeans are grown for human consumption; the rest feeds poultry or is processed into fuel, according to the USDA.
Yet older research has shown that these pesticides sometimes end up in end products.
An analysis by DM.com found that ten of the pesticides identified by the Stanford researchers appear to be used on wheat products
A 2018 study of the Environmental Working Group found glyphosate in 71 of 73 oat-based products, including breakfast cereals, snack bars and instant oats.
A sequel study in 2023 found that it was still present in about 30 percent of oat products tested.
The Environmental Protection Agency previously told DM.com that the more than 350 pesticides registered for use in the U.S. are strictly regulated.
A representative said, “EPA periodically reviews existing registered pesticides to ensure they can be used without unreasonable risks to human health and the environment.
‘The registration review program is intended to ensure that, as the ability to assess risk develops and as policies and practices change, all registered pesticides continue to meet the regulatory standard of no unreasonable adverse effect.’
Furthermore, the research published here does not prove that pesticides cause cancer, but merely establishes a link, says Professor Oliver Jones, professor of chemistry at RMIT University in Melbourne, Kosmos said.
Professor Jones said: ‘The authors are not actually saying that pesticides cause prostate cancer, just that they have found 22 pesticides that are statistically associated with prostate cancer and that more research is needed.’
As research continues and scientists figure out what does and does not contribute to cancer risk in the US, doctors can be better prepared to prevent and treat the disease.
Dr. Soerensen said: ‘By building on these findings we can increase our efforts to identify risk factors for prostate cancer and work to reduce the number of men affected by this disease.’