How Processed Meats May Affect Mental Health

By Beth Leipholtz 07/26/18

A new study examined whether the nitrates used to cure meat played a role in manic episodes. 

variety of cold cuts

Nitrates—a chemical used to cure meat—is believed to be linked to mania, a symptom of mental illness, Newsweek reports.  

According to Psych Central, manic episodes are “a mood state characterized by period of at least one week where an elevated, expansive, or unusually irritable mood exists.”

Those having manic episodes are often energized beyond the norm and may describe it as being “on top of the world.”

Researchers at Johns Hopkins Medicine studied data on 1,101 people with and without mental illnesses between 2007 and 2017. The information in the data included health, dietary and demographic information about those who participated. Of those who participated, about 55% were female, 55% were Caucasian and 36% were African American.

Researchers initially intended to determine whether being exposed to certain infections made individuals more likely to have a mental illness.

However, the researchers discovered that individuals who had been hospitalized for mania were 3.5 times more likely to have consumed processed meat before their hospitalization in comparison to a group without mental illnesses.

To test their theory, the researchers fed rats nitrates. In doing so, they discovered that those rats were more likely to exhibit hyperactivity and irregular sleep patterns when compared to rats on a normal diet.

They also found that the rats that consumed nitrates contained different bacteria in their digestive systems and exhibited differences in their brain’s molecular pathways linked to bipolar disorder. 

Dr. Robert Yolken, lead author of the study and professor of neurovirology in pediatrics at the Johns Hopkins University School of Medicine, released a statement acknowledging the prominence of processed meat in the diets of those with manic episodes.

"We looked at a number of different dietary exposures and cured meat really stood out,” he stated, according to Newsweek. “It wasn't just that people with mania have an abnormal diet.”

Previously, Yolken and his team conducted another study that implied that probiotics could decrease the likelihood that someone with mania would be re-hospitalized in the six months following hospitalization.

"There's growing evidence that germs in the intestines can influence the brain," he said. "And this work on nitrates opens the door for future studies on how that may be happening.”

Seva Khambadkone is an MD and PhD student at Johns Hopkins who participated in the study. According to Newsweek, he says genetic and environmental factors play a role in mental illness.

"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,” he stated. “Our results suggest that nitrated cured meat could be one environmental player in mediating mania."

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Beth is a Minnesota girl who got sober at age 20. By day she is a website designer, and in her spare time she enjoys writing about recovery at, doing graphic design and spending time with her boyfriend and three dogs. Find Beth on LinkedInInstagram and Twitter.