Stress gives rats, humans, the munchies: Researchers

We've all done it — stressed out from work, the kids, and traffic, we grab a jelly doughnut, a bag of chips or large fries.

For many it gives us that occasional comfort. But for those trapped in a repetitive pattern that can cause overeating due to anxiety, scientists at the University of Calgary have just completed a study researching the link between stress and appetite.

Researchers at the Hotchkiss Brain Institute have uncovered a mechanism by which stress increases food drive in rats.

The new discovery, published online this week in the journal Neuron, could provide important insight into why stress is thought to be one of the underlying contributors to obesity.

Researchers Jaideep Bains and Quentin Pittman conducted the study which created stress in rats by taking away their food. They found that the rats' stress response temporarily caused a "re-wiring" of the brain which inhibited their ability to regulate food intake.

Interestingly, the rats also chose to eat comfort foods and higher fat foods when they were stressed.

And humans, whose stress hormones are released for a myriad of different reasons, may in fact react the same way, explained Bains.

"This is important for humans because it provides an explanation for what we already see in our lives.

"If you're stressed, you'll reach for that bag of chips, because it's a comfort."

The question now, Bains says, is whether we can control the release of that stress hormone so that we can control overeating.

"That is the million dollar question in our industry."

The researchers say their study also leads to so many other questions, like what causes certain stress responses in different people, and why they cope in different ways — better or worse than others.

As well, adds Pittman, not everyone responds to stress through eating, with some choosing not to eat at all, others turning to liquor, alcohol, and some still choosing to do the right thing, like exercise.

Pittman and Bains looked specifically at nerve cells (neurons) in the region of the brain called the hypothalamus, known to have an important role in the control of appetite and metabolism and has been identified as the primary region responsible for the brain's response to stress.

The results lay the foundation for future studies to investigate the use of therapies that affect these systems in order to manipulate food intake.

They also open the door to studies looking at whether or not the stress brought about by lack of food may affect other systems.

Students working on summer courses this week at the U of C applauded the scientists research, and encouraged them to find solutions on how to curb overeating caused by stress.

"Whenever I'm stressed out over exams, or overworked, I always reach for the chocolate ice cream," said Kayla Thompson, hunched over her laptop on campus Friday morning.

"I need the miracle solution to help me stop doing that, because I don't have the willpower."

Her classmate Julie Smith added: "I know a lot of people who count on food to make them feel better, feel more relaxed. But it's only temporary, and then they just end up feeling worse that they couldn't stop eating."

By Eva Ferguson, Postmedia News

eferguson@calgaryherald.com
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