"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," co-author Seva Khambadkone said in a statement. "Our results suggest that nitrated cured meat could be one environmental player in mediating mania."
The same researchers also experimented with rats, feeding them normal chow and a piece of store-bought, nitrate-prepared beef jerky. They discovered that the animals who ate the beef jerky showed mania-like hyperactivity after a few weeks, while the rodents who ate nitrate-free foods behaved normally.
Despite the findings, the team noted that it’s too early to make any clinical conclusions. They also said occasional consumption of cured meat is not likely to cause a manic episode in most of the population.
However, they look forward to continuing their investigations.
"Future work on this association," study co-author Robert Yolken said, "could lead to dietary interventions to help reduce the risk of manic episodes in those who have bipolar disorder or who are otherwise vulnerable to mania."