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Monoamine Oxidase B (MAO-B) is an enzyme which is encoded by the MAOB gene. As with MAO-A, MAO-B breaks down neurotransmitters, specifically dopamine, and as such, plays an important role in regulating mood. Located on the X chromosome women can be heterozygous or homozygous for MAOB (as women have two X chromosomes), whereas men only carry one copy (as they have one X and one Y sex chromosome) and are therefore hemizygous.

A substantial amount of attention has focused on MAOB’s sister gene; MAOA the so called “warrior gene”, with several SNPs linked with increased aggression, although the area remains controversial. Due to this there has also been significant research into the activity of MAO-B. Due to its preference for breaking down the neurotransmitter dopamine into reactive oxygen species, studies have investigated in Parkinson’s disease and depression, both of which are associated with alterations in dopamine activity or dopamine producing neurons 1,2.


Science Grade
Brain Health
rsID Number Major Allele Minor Allele Minor Allele Frequency (%)
rs1799836 a g 45

Risk Description

The risk ‘A’ allele of the SNP A1348-36G has been associated with an increased risk of the development of Parkinson’s disease in conjunction with the risk ‘C’ allele of SNP rs1721100 in the gene FGF20. No exact mechanism has been described but it is thought that FGF20 rs1721100 promotes an increased production of dopamine, which is then rapidly degraded by a more active form of MAO-B associated with the risk ‘A’ allele of A1348-36G. This increased production and degradation leads to a buildup of reactive oxygen species which eventually damages the dopamine producing neurons 36.

An association between more active forms of MAO-B, such as those produced by the risk ‘A’ allele of A1348-36G have also been associated with depression, although no mechanism is described 7.

Direct Nutrients:*

Ingredient Active Ingredient Effect
Vitamin B2 Riboflavin phosphate

Vitamin B2 is the cofactor for MAO-B, and is required for it to function. Those carrying the normal ‘G’ allele for A1348-36G, which is associated with normal function should have no problem supplementing their diet with vitamin B2 8.

In those carrying the risk ‘A’ allele of A1348-36G, which is associated with increased activity and breakdown of dopamine, vitamin B2 plays a key role in this activity. However, attempts to remove of vitamin B2 from the diet are not recommended due to its fundamental role in general health.


Geiparvarin is a potent MOA-A and MOA-B inhibitor. It is commonly extracted from the leaves of the Australian willow (Geijera parviflora). Similar compounds are commonly used in conjunction with other medications in the treatment of Parkinsons disease.

Those with the ‘A’ allele of A1348-36G may be at risk of developing Parkinsons disease through damage to dopamine producing neurons, via increased MAO-B activity. Supplementation with geiparvarin may protect against this damage by inhibiting MAO-B activity within dopamine producing neurons 9.

Kava extract Kava pyrones

Kava-Kava is a psychoactive beverage which is widely costumed across the islands of the South Pacific. Inducing relaxation and promoting sleep, standardised root extracts containing the active kava pyrones are used as therapeutics to ease anxiety and tension.
More recently it has been shown that kava extract is a strong MAO-B inhibitor.

Those carrying the ‘A’ allele of A1348-36G, which displays increased MAO-B activity, may be at risk of developing Parkinsons disease through damage to dopamine producing neurons. Supplementation with kava extract may exert a protective effect against this damage by inhibiting MAO-B activity

Indirect Nutrients:*

Ingredient Active Ingredient Effect

Garlic has long been known to have several positive health benefits, particularly in relation to supporting good heart and brain health. As our scientific understanding of garlic has increased so has our understanding of the molecular principles behind its activities. Garlic extract has been shown to induce an increase in detected levels of dopamine, and other neurotransmitters and is thought to induce this effect by inhibiting MAO-A and MAO-B activity 11.

Whilst this study focuses on depression it is possible to hypothesize that a similar activity will occur in relation to Parkinsons disease, especially as a beneficial effect for garlic on Alzheimers disease progression has been observed 12.

As such supplementation with dietary garlic or garlic extract may prove beneficial to those carrying the ‘A’ allele of ‘A’ allele of A1348-36G, which displays increased MAO-B activity, and an increased risk of developing Parkinsons disease or depression.

Discuss this information with your doctor before taking any course of action.


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