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Study shows high-fat diet can cause anxiety – Sterling Journal-Advocate

Study shows high-fat diet can cause anxiety – Sterling Journal-Advocate
Study shows high-fat diet can cause anxiety – Sterling Journal-Advocate

A new study from researchers at CU Boulder shows that eating high-fat junk food like French fries can impact chemicals in the brain that cause anxiety. (Juan Moyano/Dreamstime/TNS)

When we’re stressed, many of us turn to junk food. But new research from the University of Colorado Boulder suggests that this strategy can backfire.

The study found that a high-fat diet in animals disrupts the gut flora, alters behavior and, through a complex gut-brain pathway, affects brain chemicals in ways that fuel anxiety.

“Everyone knows these are not healthy foods, but we tend to look at them exclusively in terms of weight gain,” said lead author Christopher Lowry, a professor of integrative physiology at CU Boulder. “When you understand that they also affect your brain in ways that can promote anxiety, the risk is even higher.”

Lowry’s team divided male adolescent rats into two groups: half were fed a standard diet containing about 11 percent fat for nine weeks; the others were fed a high-fat diet containing 45 percent fat, consisting mainly of saturated fats from animal products.

The typical American diet consists of about 36% fat.

The animals’ intestinal flora was examined throughout the study. After nine weeks, the animals were subjected to behavioral tests.

Compared to the control group, the group with the high-fat diet not surprisingly gained weight. However, the animals also had a significantly lower diversity of intestinal bacteria (in general, more diversity is considered healthier).

The high-fat diet group also showed greater expression of three genes involved in the production of the neurotransmitter serotonin in the brain – particularly in an area of ​​the brain stem associated with stress and anxiety.

While serotonin is often referred to as a “feel-good brain chemical,” Lowry points out that certain subsets of serotonin neurons, when activated, can trigger anxiety-like responses in animals. In particular, increased expression of TPH2, or tryptophan hydroxylase, one of the genes identified in the study, has also been linked to mood disorders and suicide risk in humans.

“The idea that a high-fat diet alone could change the expression of these genes in the brain is extraordinary,” Lowry said. “The high-fat diet group essentially had the molecular signature of high anxiety in the brain.”

How a dysfunctional gut can alter brain chemistry is still unclear, but Lowry suspects that an unhealthy gut damages the intestinal lining, allowing bacteria to enter the body’s circulation and communicate with the brain via a gut-brain pathway called the vagus nerve.

“If you think about human evolution, it makes sense,” Lowry said. “We’re programmed to really notice things that make us sick so we can avoid those things in the future.”

Lowry emphasizes that not all fats are bad and that healthy fats, such as those found in fish, olive oil, nuts and seeds, can actually be anti-inflammatory and good for the brain.

His advice: Eat as many different types of fruit and vegetables as possible, include fermented foods in your diet to support intestinal health and avoid pizza and chips.

Read the full story on CU Boulder Today.

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