Need a Lift? Have a Bowl of Grits, Study Suggests
A plate of spaghetti, a bowl of grits or a meal heavy in other carbohydrates can lift a person’s spirits by increasing the amount of serotonin, a powerful chemical in the brain, according to a researcher.
Dr. Richard Wurtman, a professor at the Massachusetts Institute of Technology who discussed new findings here Sunday at the American Psychological Assn.’s annual conference, said some depression, obesity and even symptoms of premenstrual stress may be caused by shortages of serotonin.
Serotonin is synthesized in the brain and is known to play a crucial role in mood, depression, appetite and sleep, among other things. Eating foods high in carbohydrates enhances the production of serotonin, Wurtman said.
They do that by triggering the secretion of insulin in the body, which in turn reduces the level of certain amino acids in the blood. It then becomes possible for more of a competing amino acid, which is essential for production of serotonin, to reach the brain.
“To be absolutely banal about it, if you had grits, sweet roll, toast and coffee for breakfast . . . then you are at this moment releasing more serotonin,” Wurtman, a professor of neuroendocrine regulation, told the audience. By contrast, a high-protein breakfast of eggs and sausage would have the opposite effect, he said.
Serotonin is just one of a number of brain chemicals, or neurotransmitters, that are affected by nutrients, Wurtman said. He said he chose to focus on serotonin because it is better understood and is affected by nutrients in an average diet.
Wurtman and his research group initially used rats to examine whether carbohydrate consumption affected serotonin and thus regulated appetite. After three to four days on a carbohydrate-free diet, the rats were given a choice of carbohydrates and other foods.
In the first half-hour, the carbohydrate-deprived group ate significantly more carbohydrates than a control group. The effect was short-lived because, according to Wurtman, their serotonin levels had returned quickly to normal.
The researchers also fed all-carbohydrate or carbohydrate and protein snacks, respectively, to two groups of rats. When they were fed again an hour later, the rats that had all-carbohydrate snacks ate less carbohydrates, while those that had been given mixed snacks ate more carbohydrates.
When Wurtman began studying the diets of a group of MIT students, he found that a certain subgroup always ate carbohydrate snacks and never ate protein snacks. Wurtman looked further and found that these students happened to be obese and reported craving carbohydrates. They also met accepted criteria for depression. He guessed that they had low serotonin levels and despite their constant snacking were not producing a high enough level of serotonin.
Wurtman gave them a type of drug called fenfluramine, which increases serotonin levels. The result was that they significantly reduced their snacking, and reduced the amount of carbohydrates they ate at meals--but not the amount of protein.
“Carbohydrate consumption seems to have an effect on the subjective feelings of these people,” Wurtman said. “Why do they feel better? I think it is because of an increase in serotonin.”
Wurtman found similar patterns among people with an unusual condition called seasonal depression: During the seasons in which they were depressed, they also reported profound carbohydrate cravings and gained weight.
But during springtime, a season when they are not depressed, their serotonin levels returned to normal and they also dramatically cut back their carbohydrate intake. Mealtime carbohydrate intake dropped from 145 to 100 grams; snack-time intake dropped from 100 to 35, Wurtman said.
Wurtman found a similar pattern among women with premenstrual stress: During one phase of their menstrual cycle, they ate far more carbohydrates than did a control group without PMS; the rest of the time, the intake of both groups was the same.
When Wurtman gave the serotonin-increasing drug fenfluramine to people with seasonal depression and people with premenstrual stress, he documented significant reductions in depression as measured by accepted psychological measures.
“What we’re beginning to see is a series of disease states affecting mood and appetite that are treatable with serotonin,” Wurtman concluded.
