How Tryptophan Affects the Mind


What is tryptophan?

There is increasing evidence that the amino acid tryptophan influences the brain in a number of positive ways. Tryptophan helps the body produce the B-vitamin niacin, which in turn produces the neurotransmitter serotonin, and serotonin is thought to have a positive effect on both depression and sleep disturbances (insomnia).

  • Click here to view a list of food that is high in tryptophan

The effects of tryptophan on the mind

A review by Spring and colleagues (1987) suggests that tryptophan hastens sleep onset (drowsiness), reduces pain sensitivity and aggression. It also lowers subjective alertness and concentration.

Especially females reported increased sensitivity to the effects of tryptophan. The authors state that it is unclear whether similar effects can be obtained through carbohydrate ingestion.

A study by Booij and colleagues (2002) suggests that tryptophan has a positive effect on mood/depression. The authors examined how depletion of tryptophan affected depressed individuals.

Depletion of tryptophan was found to have an effect in about 50% of the individuals, who actually experienced a remission from depression after the depletion.

In the late 1980s, people started eating more of tryptophan through supplements, but as this article states, an outbreak of eosinophilia-myalgia syndrome emerged, which is a syndrome that causes muscle pain and even death. As a result, the U.S. Food and Drug Administration banned the tryptophan supplements, but this only concerned supplements.

Will tryptophan-rich food make you happier?

So, it seems like eating tryptophan-rich food has some positive effects on serotonin, but diet alone only has a small to modest effect on serotonin levels, a study shows (Soh & Walter, 2011).

In closing, one should not neglect the positive influence food has on the brain, as these studies indicate, but diet alone may not do the trick. A combination of psychotherapy and the right diet is better for improving mood/depression.

Photo: Shermeee