Tyramine is an endogenous monoamine found in the body. It is also present in many foods and food items. In the body, tyramine is synthesized from the amino acid tyrosine. It is further converted into octopamine and to synephrine. Tyramine is a trace amine. Like all amines, the biological activities of tyramine are associated with that of a neurotransmitter.

The basic function of tyramine is to increase the supply of another neurotransmitter called norepinephrine. It seeks to dislodge norepinephrine in neurons, thereby increasing intraneuronal presence of norepinephrine. When tyramine increases, the level of norepinephrine also increases accordingly.

Apart from causing an increase in neurotransmitters, tyramine also interacts with another amine called monoamine oxidase. This interaction induces fat creation, and fat dissolution. This will be blocked by inhibitor medications. Another thing is that tyramine also induces glucose re-absorption in body tissues that are sensitive to insulin such as cardiac muscles and skeletal muscles. Tyramine is also thought of a medication for diabetes as studies showed that tyramine ingestions have increased glucose clearance and reduced the possibility of hyperglycemia. This activity appeared to have happened without affecting cardiovascular functions.

Sufficient increase in tyramine level in the brain, which also causes an increase in norepinephrine, will adversely affect cardiovascular functions. Endogenous and supplemental ingestion of tyramine will cause blood pressure to increase and heart rate to accelerate, an excess of which may lead to heart attack or stroke. The potent vasopressor amine, tyramine, instead acts as vasodilator. And it affects an increase in systolic blood pressure, while it does not exhibit any regular effect on diastolic blood pressure. It has modest effect on heart rate. This inconsistent behavior is assumed to be due to tyramine effect on dopamine release and epinephrine.

The dietary or supplemental ingestion of tyramine does not exhibit any significant effect on cardiovascular functions, due to the presence of monoamine oxidase network. But with the presence of monoamine oxidase inhibitors ingested through medication, the same dietary tyramine effect on cardiovascular activities will increase phenomenally.

Tyramine and MAOIs

As discussed above, bodily presence of tyramine coupled with dietary supplement of this neurochemical will greatly affect cardiovascular activity when monoamine oxidase inhibitors are present. So, when monoamine oxidase inhibitors are used to treat depression, utmost caution is to be observed with regard to diet that contains tyramine. The following foods and food items are to be avoided when MAOI medication is in force.

Monoamine oxidase (MAO) is present in the gastrointestinal tract. MAOs are enzymes that reside in the mucosa, the intestinal lining, and in the liver that make tyramine, dopamine, serotonin and norepinephrine etc., ‘pressor’ amines harmless. If these 'pressor' amines are not made harmless, they become a hazard to one’s health. When inhibitor drugs retard the catabolism of supplemental or dietary tyramine, these MAOs are soaked up and dislodge norepinephrine from sympathetic nerve endings and epinephrine from the adrenal glands. When more pressor amines are let loose, a patient may suffer from severe headache, palpitations, diaphoresis, etc. And there will be an increase in both systolic as well as diastolic blood pressures.

Tyramine and Diet Restrictions for MAOIs

Dietary restrictions are needed because of tyramine factor when using monoamine oxidase inhibitor medications. Certain food items are to be completely avoided to ward off tyramine terror.

Soups: these should be avoided as these may contain fermented bean curd, etc., which hold huge tyramine quantities.

Broad Beans : These contain L-dopa (a precursor to dopamine), which is converted to dopamine and may effect a pressor reaction and hence should be avoided.

Alcoholic Preparations: Avoid red wine and fortified wines. Beer and ales are not to be taken, at least not more than half a cup. Certain whiskeys and liqueurs cause reactions.

Yeast: All yeast products and supplements should not be consumed at all. Yeast utilized for baking purposes is safe.

Banana Skins: Only one complaint regarding banana skins. Raw banana skin contains about ten times more tyramine content than ripe banana pulp.

Shrimp Products: Shrimp pastes contain huge quantities of tyramine. So avoid taking it.

Cheese: Tyramine is produced in food items such as cheese by bacterial degradation of milk. Tyramine presence can not be estimated or predicted based on color, smell or appearance, so it should be avoided.

Soy Products: All soy products, such as bean curd, sauce, bean pastes, etc., which are in fermented state contain considerable amounts of tyramine.

Cheese: Tyramine is produced in food items such as cheese by bacterial degradation of milk. Tyramine presence can not be estimated or predicted based on color, smell or appearance, so it should be avoided.

Fish Products: Pickled, smoked herring; long frozen fish and meat, should be avoided. Fresh fish and vacuum- sealed pickled fish or CAVIAR possess only small quantities of tyramine and hence can be consumed.

Sausages and snacks: Sausages, salami, bologna, pepperoni, etc contain high doses of tyramine.

Meat Extracts: Certain brands of meat contain significant quantities of tyramine and are to be avoided. Avoid powdered and liquid dietary supplements.

Sausages and snacks: Sausages, salami, bologna, pepperoni, etc contain high doses of tyramine.

Sauerkraut: High tyramine content, so avoid consuming it.