Do Bananas Increase Serotonin?

Bananas contain serotin, but this serotonin cannot cross the blood-brain barrier

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Do Bananas Increase Serotonin?

If many health and fitness sites around the Internet are to be believed, bananas are a miracle cure for many conditions, including depression. The theory goes that they contain serotonin, so eating them should increase the level of serotonin in your brain and relieve your depression.

What is Serotonin?

Serotonin is a chemical found in the human body. It carries signals along and between nerves -- a neurotransmitter.

It is mainly found in the brain, bowels and blood platelets. Serotonin is thought to be especially active in constricting smooth muscles, transmitting impulses between nerve cells, regulating cyclic body processes and contributing to wellbeing and happiness.

Serotonin is regarded by some researchers as a chemical that is responsible for maintaining mood balance, and that a deficit of serotonin leads to depression.

The word serotonin comes from its discovery when it was isolated in 1948 by Maurice M. Rapport and initially classified as a serum agent that affected vascular tone.

Serotonin is manufactured in the brain and the intestines. The majority of the body's serotonin, between 80 to 90 percent, can be found in the gastrointestinal (GI) tract. It can also be found in the blood platelets and the central nervous system (CNS).

As serotonin can be found widely across the body, it is believed that the chemical plays a role in influencing a variety of body and psychological functions.

Bananas and Serotonin

While it is true that bananas contain serotonin, this serotonin is not able to cross the blood-brain barrier. What this means is that the serotonin found in bananas can't possibly increase your brain's serotonin content because it is physically unable to get inside it. If it can't get inside the brain where it is needed, then it can't help your depression.

Eating bananas may not be completely useless in helping depression, however. While they can't directly supplement serotonin, they may be able to affect it indirectly due to the fact that they are high in vitamin B6. Vitamin B6 is necessary for your body to synthesize its own serotonin, and, if you are low on this important vitamin, getting more of it in your diet can help boost your natural serotonin production.

The current RDA for Vitamin B6 for adult men and women aged 19 to 50 is 1.3 mg daily. One medium banana will give you about 20% of the RDA.

Other excellent sources of vitamin B6 include:

  • Fish
  • Beef liver and other organ meats
  • Potatoes and other starchy vegetables
  • Fruit (other than citrus)
  • Fortified cereals

References:

Medical News Today. Serotonin: Facts, what does serotonin do?

Young, Simon N. "How to increase serotonin in the human brain without drugs." Journal of Psychiatry and Neuroscience 32.6 (2007): 394-9.

"Dietary Supplement Fact Sheet: Vitamin B6. " Office of Dietary Supplements. National Institutes of Health. Accessed: March 27, 2012.

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