Researchers from Johns Hopkins University School of Medicine suggest that nitrates used to cure meats may contribute to mania.
Mania is a state of elevated mood, which is generally seen in people with bipolar and schizoaffective disorders. Nitrates act as a preservative in cured meat products and previous researches have linked it to some cancers and neurodegenerative diseases. Based on this information, the researchers suspected a link of nitrates in mania. The researchers collected demographic, health and dietary data between 2007 and 2017 on 1,101 individuals aged between 18 and 65 with and without psychiatric disorders. It was observed that among people who had been hospitalized for mania, a history of eating nitrate-cured meat before hospitalization were approximately 3.5 times higher than the group of people without a psychiatric disorder. However, the amount of nitrate-cured meat required to boost risk of mania was not deduced by the researchers as the dietary survey did not ask about frequency or time frame of nitrate-cured meat consumption.
In an experiments with lab rats, the team fed one group with normal rat chow, and the other received both normal chow and a piece of store-bought, nitrate-prepared beef jerky every other day. It was observed that within two weeks, the rats receiving the jerky showed irregular sleeping patterns and hyperactivity. The team collaborated with a Baltimore-based beef jerky company to create a special nitrate-free dried beef. In the second experiment, some rats were fed the store-bought, nitrate-prepared jerky and others the nitrate-free formulation. It was observed that the animals, which consumed the nitrate-free meat behaved similarly to a control group. However, the animals that consumed the nitrate- cured meat showed sleep disturbances and hyperactivity. Furthermore, analysis of the gut bacteria of the different groups of rats showed that animals with nitrate in their diet had different patterns of bacteria living in their intestines than the other rats. Moreover, differences in several molecular pathways in the brain of the animals were observed that have been previously implicated in bipolar disorders. The research was published in Molecular Psychiatry on July 18, 2018,