Diet and the Brain

A study in the Proceedings of the National Academy of Sciences finds that brain chemicals linked to addiction are in play with a high-sugar diet, and a study in the Archives of Internal Medicine shows that a high-carb diet had lasting mood-elevation effects. Cynthia Graber reports

What you eat affects more than physical health. Two new studies have added to the growing evidence linking the stomach and the brain.

In a report in the Proceedings of the National Academy of Sciences, researchers studied how junk food can trigger addiction behaviors. The brain chemical corticotropin-releasing-factor, CRF, is linked to motivation, and plays a role in drug and alcohol withdrawal and relapse. Researchers had rats eat normal food, then binge on sugar and chocolate-flavored snacks. When the rats went off the junk, they expressed CRF, just as do rats going through withdrawal. The rodents also had more anxiety and were less interested in normal food.

Another study, published in the Archives of Internal Medicine, looked at human moods. Researchers followed 106 overweight people. Half followed a low-carb, very high-fat diet, and half ate a high-carbohydrate, low-fat diet. After a year, both groups averaged about 30 pounds weight loss. And though both groups’ moods improved after two months, only the low-fat, high-carb group kept up the good feelings. So what we eat doesn’t just go to our waists—it also goes to our brains.

—Cynthia Graber