A popular belief--caused, according to the University of Hawaii, by a viral email forward--claims that bananas can alleviate depression. This information is not accurate. However, although a banana cannot effectively treat depression, some of its nutrients can help your body fight against depressive symptoms.
The amino acid tryptophan helps your body make serotonin, a brain chemical that regulates mood, explains MedHelp. Feelings of clinical depression stem from low serotonin levels; hence, MedHelp adds, depressed people tend to have low levels of tryptophan. The theory that bananas relieve depression began because bananas provide tryptophan. Additionally, bananas provide vitamin B6, adds the "American Journal of Clinical Nutrition," which your body also needs in order to manufacture serotonin from tryptophan.
Although bananas contain tryptophan, they only contain a very small amount. Further, notes the university, nearly all protein-based foods also include tryptophan; hence, bananas do not provide a unique or particularly significant source. Accordingly, bananas probably cannot prevent or cure depression. MedHelp agrees that tryptophan doesn't provide an appreciably effective treatment for depressive symptoms.
People who suffer from depression commonly lack energy and struggle to concentrate. Norepinephrine, a brain-related chemical known as a neurotransmitter, stimulates brain activity and enhances alertness and concentration, according to the Franklin Institute. Your body requires both tyrosine, an amino acid, and vitamin B6 in order to manufacture norepinephrine, the Institute explains; bananas provide both. Although eating bananas will not immediately restore your energy, it can help ensure your brain activity isn't hindered by a lack of norepinephrine.
Insomnia is another common symptom of depression. According to the University of Maryland Medical Center, foods that contain tryptophan can help a person fall asleep more easily. Hence, eating a banana shortly before going to bed at night may help prevent or reduce insomnia due to insomnia.
Risk of Depression
Bananas provide vitamin B6, which helps your body create serotonin, explains Medline Plus. Consequently, according to a study published in the "American Journal of Clinical Nutrition," a lack of B6 increases your risk of developing depression, and a sufficient amount decreases the risk. The journal notes that consuming B6 doesn’t necessarily cure or prevent depression, and Medline Plus warns that excessive B6 can endanger your nervous system. However, the study also concludes that a healthy intake of B6--from foods such as bananas--can decrease your risk for depression, especially as you grow older.