Meat mania? Chemicals in hot dogs could cause manic episodes, scientists say

Scientists at Johns Hopkins University said in a new study that nitrates, which are used to cure and process various meats, including hot dogs and jerky, are linked to episodes of mania in rats.
Scientists at Johns Hopkins University said in a new study that nitrates, which are used to cure and process various meats, including hot dogs and jerky, are linked to episodes of mania in rats. AP

Eating a lot of hot dogs, beef jerky, salami and other processed meats could do more than just add a few extra pounds — it could cause a serious mental condition called mania.

That’s according to a new study from scientists at Johns Hopkins Medicine published July 18 (National Hot Dog Day) in the journal Molecular Psychiatry. 

The study found a link between consumption of nitrates, which are chemicals used to cure and process meat snacks, and episodes of mania, “a serious neuropsychiatric condition associated with significant morbidity and mortality.”

“We looked at a number of different dietary exposures and cured meat really stood out,” study lead author Robert Yolken, M.D., said in a statement. “It wasn’t just that people with mania have an abnormal diet.”

Mania is an abnormal mental state marked by feelings of hyperactivity, excitability, irritability, racing thoughts, risk-taking and insomnia, according to the National Institutes of Health. It is often associated with bipolar disorder, a condition wherein people fluctuate between periods of mania and depression.

The scientists said people hospitalized for mania had about three times the odds of having eaten nitrate-cured meats than others, and rats fed a diet with added nitrates showed symptoms of mania within a few weeks, according to the study.

Nitrates are chemicals that are sometimes added to processed and cured meats as preservatives. They can be found in things like salami, hot dogs, jerky, bacon and lunch meats, though those products can sometimes be purchased nitrate-free.

They are found also naturally in other foods and in the environment, and there is limited evidence that overexposure to the chemicals can cause cancer, according to the Centers for Disease Control.

Yolken was originally interested in studying the effect foods may have on mental illness, and conducted a demographic study of 1,101 people both with and without mental disorders. It was from that pool of data that Yolken noticed the association between mania and nitrate consumption, according to a release from Johns Hopkins.

To test the connection, Yolken fed lab rats diets of added nitrates. The amount of nitrate was around the same as if a human ate one hot dog or beef jerky stick every day, according to CTV News.

“We tried to make sure the amount of nitrate used in the experiment was in the range of what people might reasonably be eating,” Yolken said in a news release.

After only a few weeks, the rats began to show signs of hyperactivity, while the rats that were not fed the nitrates showed no changes, according Johns Hopkins. The scientists also found changes in the microbacteria in the rats’ guts, according to the study.

This doesn’t necessarily mean there’s a cause-and-effect relationship, the scientists are quick to point out. But it may indicate that cured meats and nitrates are at least a factor in mania.

“It’s clear that mania is a complex neuropsychiatric state, and that both genetic vulnerabilities and environmental factors are likely involved in the emergence and severity of bipolar disorder and associated manic episodes,” Seva Khambadkone, who worked on the study, said in a statement. “Our results suggest that nitrated cured meat could be one environmental player in mediating mania.”

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