Serotonin: 9 Questions and Answers
5. Can diet influence our supply of serotonin?
It can, but in a roundabout way. Unlike calcium-rich foods, which can directly increase your blood levels of this mineral, there are no foods that can directly increase your body's supply of serotonin. That said, there are foods and some nutrients that can increase levels of tryptophan, the amino acid from which serotonin is made.
Protein-rich foods, such as meat or chicken, contain high levels of tryptophans. Tryptophan appears in dairy foods, nuts, and fowl. Ironically, however, levels of both tryptophan and serotonin drop after eating a meal packed with protein. Why? According to nutritionist Elizabeth Somer, when you eat a high-protein meal, you "flood the blood with both tryptophan and its competing amino acids," all fighting for entry into the brain. That means only a small amount of tryptophan gets through -- and serotonin levels don't rise.
But eat a carbohydrate-rich meal, and your body triggers a release of insulin. This, Somer says, causes any amino acids in the blood to be absorbed into the body -- but not the brain. Except for, you guessed it -- tryptophan! It remains in the bloodstream at high levels following a carbohydrate meal, which means it can freely enter the brain and cause serotonin levels to rise, she says.
What can also help: Getting an adequate supply of vitamin B-6, which can influence the rate at which tryptophan is converted to serotonin.
6. Can exercise boost serotonin levels?
Exercise can do a lot to improve your mood -- and across the board, studies have shown that regular exercise can be as effective a treatment for depression as antidepressant medication or psychotherapy. In the past, it was believed that several weeks of working out was necessary to see the effects on depression, but new research conducted at the University of Texas at Austin found that just a single 40-minute period of exercise can have an immediate effect on mood.
That said, it remains unclear of the exact mechanism by which exercise accomplishes this. While some believe it affects serotonin levels, to date there are no definitive studies showing that this is the case.
7. Do men and women have the same amount of serotonin -- and does it act the same way in their brain and body?
Studies show that men do have slightly more serotonin than women, but the difference is thought to be negligible. Interestingly, however, a study published in September 2007 in the journal Biological Psychiatry showed there might be a huge difference in how men and women react to a reduction in serotonin -- and that may be one reason why women suffer from depression far more than men.
Using a technique called "tryptophan depletion," which reduces serotonin levels in the brain, researchers found that men became impulsive but not necessarily depressed. Women, on the other hand, experienced a marked drop in mood and became more cautious, an emotional response commonly associated with depression. While the serotonin processing system seems the same in both sexes, researchers now believe men and women may use serotonin differently.