A recent study by the Environmental Working Group found a chemical pesticide in oat-based foods sold in the United States — but how concerned do consumers need to be about potential health impacts? 

The pesticide, chlormequat, is used as a growth regulator for plants, according to the National Library of Medicine. It is approved in Canada and other countries for use on commercial crops of cereal grains, which can be imported to the U.S.

In EWG’s study, the chemical was detected in 77 of 96 urine samples taken from 2017 to 2023, with levels increasing in the most recent years. The group also tested 25 samples of non-organic oat-based foods from U.S. grocery stores, including Quaker Oats and Cheerios, and found chlormequat in 92% of them.

“Animal studies link chlormequat to reduced fertility, harm to the reproductive system and altered fetal growth,” the group says.

Experts say it’s good to be mindful of this, but not to fixate on it as we don’t yet know what it may mean for human health.

“I think that it was the first study in the right direction, but it’s too early to tell,” Dr. Tomer Singer, chief of reproductive endocrinology and infertility at Northwell Health, tells CBS News. “And if we should be concerned? I think it warrants definitely more extensive and prospective study, which unfortunately take years to obtain.”

His advice? “I think that the main thing that we need to advise our patient who are trying to conceive is to have a healthy, balanced diet, eating fruits and vegetables as we usually recommend.”

Studies on chlormequat side effects

Dr. Asima Ahmad, chief medical officer and co-founder of fertility care platform Carrot Fertility says there have been several animal studies on chlormequat’s impact on fertility, which have shown:

• Mating difficulties and disruption
• Decreased sperm motility and fertilization rates
• Dltered embryo growth and development
• Fetal development during pregnancy

These studies all focused on animals like pigs and rats — not humans. 

“Though these exact studies were not conducted with humans, using animal models can help us predict how these same exposures may affect humans,” Ahmad explains.

Should I not eat oats to support my fertility? 

Should oats be out of your diet? Not necessarily — grains are part of a healthy, balanced diet, Singer points out — but experts say the study can help guide mindful shopping and decision-making. 

“It’s going to be the responsibility of each and every patient to read the ingredients of every product that they consume,” Singer says. “Nothing in high amounts is healthy. Try to diversify and not to eat the same product or the same exact grain and from the same company over and over again. I think that’s the best advice we can tell our patients.”

If you want to go further, you can opt for organic. 

“Similar to how I counsel my own patients, I recommend trying to eat organic and freshly prepared foods as much as possible,” Ahmad says.

The companies behind Cheerios and Quaker Oats say they stand by the safety and quality of their products.

“All our products adhere to all regulatory requirements,” a spokesperson for General Mills, the maker of Cheerios, told CBS News in a statement. “Food safety is always our top priority at General Mills, and we take care to ensure our food is prepared and packaged in the safest way possible.”

A statement from Quaker said: “We have a comprehensive food safety management system in place. We adhere to all regulatory guidelines to ensure the safest, highest quality products for our consumers.”

The study comes amid an increase in infertility in the United States, with about 12% to 15% of couples unable to conceive after one year of trying, according to the National Institutes of Health.

Singer explains diet, lifestyle and environment all play a role in fertility. But instead of focusing on oats specifically, he says it’s better to keep a big picture of health in mind. 

“We know that fruits and vegetables and balanced diet — what we call the Mediterranean diet — is healthy for fertility,” Singer notes, noting that balancing carbohydrates, fat and sugars, taking prenatal vitamins and being physical active are all part of supporting your fertility goals. 

-Kate Gibson contributed to this report.