A study in the open access journal BMC Biology in 2005 found that rats who were stressed wanted to wolf down lots of sugar cubes because of high brain levels of a chemical called corticotropin-releasing factor — a stress hormone that humans also have.
The scientists concluded that stressed people might be more likely to crave things that made them feel good – like eating sugar or taking drugs.
OK, that helps explain why you might want to eat nice-tasting sweets when you are stressed out. But you might want to just go straight for dark chocolate, if it’s stress relief you’re after.
In another study, volunteers who said they were really stressed out ate dark chocolate for two weeks. When tested, scientists found reductions in stress hormones and other stress-related biochemical changes.
“The study provides strong evidence that a daily consumption of 40 grams (1.4 ounces) during a period of 2 weeks is sufficient to modify the metabolism of healthy human volunteers,” the scientists said in the press release.
Another study, presented in late 2008 at the American College of Neuropsychopharmacology annual meeting, found that sugar is addictive to rats. Sugar binges changed the levels of the rats’ brain chemicals that control how much they want and like something. When their sugar was taken away, the rats did pretty much whatever they could to get sugar again. Yikes!
Researcher David Diamond, found some contradictions to conventional dietary knowledge — that sugar, not fat, may be the culprit in causing stress and unhealthy eating habits. Diamond’s work blossomed when he uncovered a possible link between diet and stressful memories.
Two weeks into the study, each rat was given a “bad experience” — a minor shock when entering a certain room. Usually, when given a similar shock, rats have forgotten it in studies.
A month later, the rats were brought into the same room. Those on the American diet showed signs that they still remembered the trauma, while the Atkins and control rats showed no sign or fear of memories, Diamond said.
Next, the researchers put the rats in a room where they could either hide in the dark or go into the light and explore their surroundings. Only 20 percent of the American diet rats chose to explore their surroundings. However, more than 50 percent of rats on the Atkins diet were curious and unafraid to explore.
So, what did that tell researchers? Maybe it’s the sugar — not the fat — that people should lookout for.
“I think the study is unique,” Seetharaman said. “Previous information has inundated the American public and conventional wisdom that fat is bad for you … while this study has shown that sugar … may contribute to impairing brain function which has not been widely studied.”
People crave foods higher in sugar and fat when stressed, Diamond said. It’s a “vicious cycle.” People try to relieve their stress by eating more sugar-filled foods.
Diamond said the study should be ready for publication by the end of the month. From there, its fate will be determined by peer reviews. The study was funded through a research grant from the Veteran’s Association, an organization interested in helping people who have been traumatized, Diamond said.
“That’s the main focus of my work, to help people who have been traumatized in combat,” he said. “Soldiers with traumatic experiences in combat are prone to heart disease … What harms our health in modern times is the sedentary lifestyle, which interacts with stress — which interacts with diet to create a toxic environment.”