High anxiety

Bad news for hangover sufferers. That greasy burger and fries you reach for the morning after may actually compound your problems.

According to a study by the CU Boulder – a school that knows a thing or two about hangovers, speaking from personal experience – a high-fat diet can make you even more anxious.

Of course this applies not just to irrational alcohol detox jitters but in general. Researchers found a high-fat diet disrupts gut bacteria and, through a complex gut-brain pathway, influences brain chemicals that fuel anxiety. Sort of like throwing whiskey on the fire.

“Everyone knows that these are not healthy foods,” lead author Christopher Lowry, a professor of integrative physiology, said. “If you understand that they also impact your brain in a way that can promote anxiety, that makes the stakes even higher.”

Granted the research so far only applies to rats, where half got a standard diet of 11% fat for nine weeks and the other got a high-fat diet of 45% fat, consisting mostly of fat from animal products. For reference, the typical American diet is about 36% fat.

When compared to the control group, the high-fat group, not surprisingly, gained weight. But the animals also showed significantly less diversity of gut bacteria as well as higher expression of genes involved in production of serotonin – particularly in a part of the brain associated with stress and anxiety.

While serotonin is often billed as a “feel-good” brain chemical, Lowry notes that certain subsets of serotonin can prompt anxiety-like responses and mood disorders. 

“To think that just a high-fat diet could alter expression of these genes in the brain is extraordinary,” said Lowry. “The high-fat group essentially had the molecular signature of a high anxiety state.”

Just how the gut biome can affect brain chemicals remains unclear, however.  But Lowry suspects an unhealthy gut compromises the gut lining, enabling bacteria to slip into the body and communicate with the brain via the vagus nerve.

“If you think about human evolution, it makes sense,” Lowry said.  “We are hard-wired to really notice things that make us sick, so we can avoid those things.”

Lowry stresses not all fats are bad, and, in fact, healthy fats like fish, olive oil, nuts and seeds can be good for the brain. His advice is what your mom’s been telling you all along: Eat more fruit, veggies and fermented foods (no, beer or wine do not qualify) and lay off the pizza and burgers.