MAO-A (Monoamine oxidase A) is a critical enzyme involved in breaking down important neurotransmitters such as serotonin, norepinephrine, and dopamine. Males can only have a heterozygous MAO-A, while females can have heterozygous or homozygous variants. This requires extra support of the pathways including vitamin B6, folate, B12, B2, magnesium, vitamin C and ashwagandha. It also requires more fruit and vegetables to support oxidative stress. See the diagram below to visualize how it all works.

BH4 Cycle, COMT, MAO-A

One of the major things to take away from this diagram and MAO-A, is the importance of healthy BH4 and sufficient B12, folate, vitamin C and magnesium intake for dopamine and serotonin to break down properly. High amounts of both of these lead to mental imbalances. These neurotransmitters are also sensitive to extremes of blood sugar. It is important that you get balanced meals every 3-4 hours, but that you also do not overload on carbohydrates and sugar which will spike neurotransmitters.

Digestion and MAO-A

Too much serotonin can also lead to digestive issues. Approximately 95% of serotonin is housed in the gut, where the majority of communication occurs within the digestive tract; 90% of this information will be translated to the brain. In a healthy person, after serotonin is released into the gut and initiates an intestinal reflex, it is taken out of the bowel by a serotonin transporter, or SERT, found in the cells that line the gut wall. Some people do not have enough SERT, so they wind up with too much serotonin floating around causing diarrhea. There is evidence to support interaction between MAOA and serotonin transporter (SERT) genes.

Exercise and MAO-A

In terms of exercise, it is important that you avoid extreme exercise. This will cause rushes of serotonin and your body will have trouble breaking it down, leading to slow recovery and more fatigue.

Drugs and MAO-A

It is extremely important that you do not take any medications that are MAO inhibitors. Findings suggest that individuals with polymorphisms in MAO genes, which result in altered MAO function, may be at increased risk for developing the serotonin syndrome when taking serotonin-enhancing drugs such as tramadol. Drugs implicated in serotonin syndrome include members of several classes of drugs, including SSRIs, MAOIs (including reversible MAOIs like moclobemide), triptans for migraines, St. John’s Wort, 5-HTP, the antibiotic linezolid (Zyvox) methylene blue and atypical opioids such as tramadol.

Estrogen and MAO-A

Estrogen plays a major role in MAO-A, and therefore estrogen and progesterone levels should be assessed for optimal function in females.

Low and High Estrogen