Hot chili peppers are good for a lot of things, like seasoning your food and clearing your sinuses. But it turns out that the spicy chemical in chilis, called capsaicin, may have bigger effects on the body than we thought, especially when it comes to how much we eat.
A new study shows that the same receptors in the body that respond to capsaicin (producing that well-known burning sensation) are also partly responsible for telling the brain when you've had enough to eat. When we eat, our stomachs stretch and activate nerves that tell the brain we're getting full, says Amanda Page, an associate professor at the University of Adelaide in Australia and senior author on the study, in an email.
The study found that the activation of these nerves is at least partly regulated by our capsaicin receptors. One implication is that eating more capsaicin could activate these receptors and cause people to feel more full, thus reducing their food intake and helping with weight loss.
Since the study was only performed in mice, no one can say for sure yet if the results hold true for humans. But Jason Kim, a professor at the University of Massachusetts Medical School who has conducted similar research, says some past studies have shown that capsaicin actually can cause humans to eat less food.
The catch: The new study also found that high-fat diets disrupted the capsaicin receptors in mice, making them less sensitive to the stretching in their stomachs and prone to eating more. If the same holds true in humans, then high-fat diets could cause people to over-eat and have trouble losing weight, Page says. And eating more capsaicin won't help reduce food intake in people whose receptors have already been dulled.
Page says she and her colleagues are now trying to figure out exactly why high-fat diets disrupt the signals that tell the body it's full. She says she hopes their research "will eventually lead to a target for the treatment of obesity."