(July 24, 2018) New research indicates that nitrates — chemicals used to cure meats such as in beef jerky, hot dogs and other processed meats — may contribute to mania, an abnormal mood state common in patients with bipolar disorder.
Treatment Advocacy Center Board Member Robert Yolken, MD, and colleagues from Johns Hopkins University found that individuals hospitalized for mania had three and a half times higher odds of previously eating nitrated meats than individuals with no history of psychiatric disorders.
Mania is a state of elevated mood and energy that can last anywhere from a week to many months and is generally seen in people with bipolar disorder. Manic states can include delusional thinking and may lead to dangerous risk-taking behaviors.
Eating nitrate-cured meats does not necessarily cause mania, but the results indicate that certain diets and bacteria in the gut may contribute to disorders that affect the brain. The authors replicated the study in rats and found similar results - rats who had been fed nitrate-rich foods exhibited extreme hyperactivity compared to rats fed a normal diet.
The authors also analyzed ten years of patient records from more than 1,100 patients at Sheppard Pratt Health System in Baltimore, Maryland. While a history of eating cured meats was significantly more likely to result in hospitalization for those with psychiatric disorders and manic episodes, eating cured meats was not associated with greater odds of being diagnosed with schizoaffective disorder, bipolar disorder or major depressive disorder.
"We looked at a number of different dietary exposures and cured meat really stood out," says Dr. Yolken. "It wasn't just that people with mania have an abnormal diet."
Nitrates have been previous linked to some cancers and neurodegenerative diseases, but evidence to the validity of the association is mixed.
Dr. Yolken expresses caution in interpreting these results, indicating more research is needed before making any sort of conclusions about dietary changes for individuals with bipolar disorder. However, the research has been gaining publicity already being publicized by national news outlets such as NBC News and The Atlantic.
Elizabeth Sinclair
Director of Research
References:
- Khambadkone, S. G. et al. (2018, July). Nitrated meat products are associated with mania in humans and altered behavior and brain gene expression in rats. Molecular Psychiatry.
SMRI is a supporting organization of the Treatment Advocacy Center, whose mission includes supporting the development of innovative treatments for and research into the causes of severe and persistent psychiatric illness. The Treatment Advocacy Center, which accepts no funding from pharmaceutical companies, also was founded by Dr. Torrey.