Jerky Beef could make mania in bipolar disorder worse

Meanwhile, salted meats were not significantly associated with any other types of psychiatric disorders, such as major depression, and none of the other foods requested from participants were significantly correlated with mania.

Here's where I pause your tweet: "Correlation does not imply causation!"

This is true, and although the authors have controlled for many different factors, this does not prove that dried beef caused mania. After all, it could be that people who were already on the verge of becoming obsessive have been late, sneaking to 7-11 and filling up on Slim Jims. (The authors controlled for the education of mothers subjects, which is an approximation of socio-economic status, but not perfect.)

So they decided to test this hypothesis further. They turned to rats.

First, they fed a group of normal food rats, and another group a piece of dried beef every other day. They tried to make it roughly proportionate to a rat-adjusted version of the amount that a human would eat for a snack. In two weeks, the jerky eating rats started to sleep irregularly and behave more excitedly. In other words, they seemed manic.

"We were able to obtain an effect on rats that corresponded quite well to what we see in humans," says Robert Yolken, professor of neurovirology at the Johns University School of Medicine. Hopkins. and one of the authors of the study.

They found the same difference when they compared rats that received jerky and rats that were given a special meat without nitrate. Rats of meat without nitrate? Ordinary. The beef-jerky rats? Extremely hyper.

Yolken and his team then looked into the brains and guts of rats. Their brains exhibited gene and molecular pathway changes similar to those seen in people with bipolar disorder. What's more, manic rats, those with nitrates in their diet, had different types of bacteria living in their guts than the control rats.

Researchers do not know exactly why nitrates have had this effect. Nitrates have antibacterial properties, and Yolken thinks that the preservative may have altered the microbiomes of rats and humans. In previous research, he and his colleagues discovered that when people who were hospitalized for a manic episode were given probiotics, they were less likely to be rehospitalized in the next six months.

Changes in the microbiome affect the brain. According to the researchers, bacteria could send signals across the vagus nerve, which connects the intestine and the brain. Or they could release chemicals called butyrates that cross the circulatory system to the brain, where they influence the production of mood-regulating hormones called neurotransmitters.

Yolken and his colleagues "have embraced the innovative approach of finding something in humans," said Melvin McInnis, an expert in bipolar disorder at the University of Michigan, who said: was not involved in the study. "This brings credibility to the study in a way that would lead us to consider these results as valid."