Interest in the connection between nutrients and mood has increased greatly. The medical community is just beginning to understand how nutrients in food affect the way you feel. Amino acids influence emotions such as anger and aggression, but the mechanisms involved are complex. Discovering more about this connection plays a crucial role in developing new -- and perhaps more natural -- treatments for anger issues.
Scientists have long known that amino acids can excite or calm the brain by increasing or decreasing the rate at which neurons fire. Amino acids such as GABA slow down neural firing, which has a calming effect. For example, antianxiety medications work by increasing GABA production. In contrast, the amino acid tyrosine has a stimulating effect. The neurons that amino acids influence send signals to your limbic system, an area deep in the brain that controls mood, among other things.
Homocysteine is a normally harmless amino acid created from protein metabolism and converted to beneficial substances such as the powerful antioxidant glutathione. Adverse effects occur when your body fails to convert homocysteine and blood levels remain elevated. High homocysteine is most commonly associated with an increased risk of cardiovascular disease. However, researchers at Ohio State University found that it is also associated with anger and hostility, according to a study published in the June 2000 issue of the journal "Life Sciences."
Tryptophan is an amino acid that plays an important role in your mood through the production of serotonin. Decreased levels of serotonin have been linked to depression, hostility and aggression. Although new research into this area is lacking, studies published in the 1990s provide a link between low tryptophan levels and anger. Researchers at the University of Texas Houston administered a low tryptophan diet to healthy males for 24 hours followed by a tryptophan-free amino acid mixture. The results were increased aggression, according to a study published in the July 1996 issue of the journal "Psychopharmacology."
A complex system regulates your mood, and amino acids play a part. Other factors not relating to amino acids can also influence your emotions. A defect in the serotonin transporter gene increases feelings of anger and depression. Hormones also influence your mood. The medical community has long known that elevated levels of the hormone prolactin cause anger and hostility. Scientists are still learning about the complexities of mood regulation.
Janet Renee is a clinical dietitian with a special interest in weight management, sports dietetics, medical nutrition therapy and diet trends. She earned her Master of Science in nutrition from the University of Chicago and has contributed to health and wellness magazines, including Prevention, Self, Shape and Cooking Light.