Enjoyable activities like eating good food and having sex don’t just provide pleasure. They lower stress by blocking anxiety responses in the brain, researchers say.
A team at the University of Cincinnati found that pleasurable experiences also seem to have longer-term benefits because the relaxing effects lasted at least seven days.
“These findings give us a clearer understanding of the motivation for consuming ‘comfort food’ during times of stress,” lead researcher Yvonne Ulrich-Lai said in a statement. “But it’s important to note that even small amounts of pleasurable foods can reduce the effects of stress.”
Ulrich-Lai and colleagues including James Herman, director of the school’s Laboratory of Stress Neurobiology, gave rats access to a sugar solution twice a day for two weeks. They then measured the rodents’ behavioral and physiological responses to stress.
The rats who were given sugar water had lower heart rates and stress hormone levels and were more adventurous and social with other rats than the ones in the control group with no access to the sugar solution.
“That totally makes sense,” said AOL’s mental health expert, Dr. Danial Carlat. “Certainly in my clinical work, when patients are feeling either anxiety or depression, it’s very helpful to get them to focus on something pleasurable in their lives.”
Carlat said he often asks his depressed or anxious patients to make a list of things that give them pleasure, whether it’s eating ice cream, watching a TV show or movie they like, taking a walk, taking a bath or shopping. He then has them engage in one of those activities regularly.
“Sometimes people forget about things that used to give them pleasure, especially if they’re depressed, so I have to help jog their memory,” he told AOL Health. “Ultimately this finding does certainly jive with my clinical experience.”
In other experiments, rats were given a solution sweetened with saccharin instead of sugar. They showed similar reductions in stress levels. So did the animals that were given access to sexually responsive partners.
However, the rats who were fed sugar water directly through their stomachs didn’t have lower stress responses, according to the findings published in PNAS, the journal of the National Academy of Sciences.
“This indicates that the pleasurable properties of tasty foods, not the caloric properties, were sufficient for stress reduction,” said Ulrich-Lai.
The researchers measured the rats’ physiological responses to stress by looking at activity in the hypothalamic-pituitary-adrenocortical (HPA) axis, which is controlled by a structure in the brain known as BLA, or basolateral amygdale.
They saw that the rodents with exposure to sex and tasty food had milder HPA axis reactions to stress.
“It’s a reasonable conclusion if it’s true that the animal model of stress they used in this study mirrors actual human stress,” said Carlat. “The use of animal models in psychiatry research is very, very tricky. But it sounds reasonable because both rats and humans have similar brain structure and similar stress hormones.”
The stress reduction effect in the rodents was blocked when the BLA had lesions or other damage, meaning that the brain structure’s nerve activity is required for the stress-busting outcome to occur.
“Our research identifies key neural circuits underlying the comfort food effect,” said Ulrich-Lai. “Further research is needed, but identification of these circuits could provide potential strategies for intervening to prevent or curtail increasing rates of obesity and other metabolic disorders.”
The research was funded by grants from the National Institutes of Health.