Tyramine is common compound that can be found in many animals and plants. Monoamine oxidases and other enzymes are involved in its production. Tyrosine becomes tyramine through normal processes of decay and fermentation, so it ends up in food.
This natural chemical is used by the body to control blood pressure. It is found in food but the actual quantity depends on the diet. There is no generally recommended level of tyramine in the body because every individual reacts differently to it. Some people can safely consume large quantities of tyramine from food because they are able to process it easily.
Many plants and animals metabolize tyramine, which is a common natural compound. It is also found in food that is no longer fresh or has started fermentation, as a by-product of an amino-acid named tyrosine. Tyramine is a derivative of ammonia and includes nitrogen in its chemical structure, so it is classified in the chemical group of amines.
In human biology, the compound is also known as 4-hydroxyphenethylamine. It triggers the release of catecholamines from adrenal glands in the blood stream, a group of hormones that have important effects. Dopamine, norepinephrine (noradrenaline) and epinephrine are all part of this group. These cause various reactions in the body but a shared effect is an increase of the heart rate and blood pressure when they are released.
People who undergo treatments based on monoamine oxidase inhibitors (MAOIs) should avoid high blood pressure, which can be dangerous for them. The body has a natural mechanism to prevent the build-up of tyramine, based on the enzyme monoamine oxidase. If this compound is inhibited through medication, the result can be an excessive level of tyramine and eventually a heart attack. As a precaution, people who take MAOIs are advised to follow a diet low in tyramine.
Scientists also suspect that tyramine might be the cause of migraines in some people. However, multiple serious studies on this issue have failed so far to establish a definitive connection. The theory is that tyramine indirectly causes blood vessels in the brain to contract due to the release of catecholamine hormones. Blood vessels then dilate, after the initial effect is no longer active. This is thought to cause migraines in people who are sensitive to headaches. Some people have reported fewer migraines after observing a diet that excludes all foods with a content of tyramine.
The body can also convert tyramine to another compound named octopamine, after a long time if large amounts are available. Octopamine is stored in the synaptic vesicles, the same location where a number of catecholines are usually found before they are released in the blood flow. It seems that this compound can actually replace the hormones, thus eliminating their effects. This effect might explain the condition known as orthostatic hypotension, which is a general decrease in blood pressure. The theory seems to be validated by the presence of this condition in people on MAOI medication. However, the role of octopamine is very poorly understood and more research is needed.
Tyramine can reach high levels in foods that have expired or started to ferment. It is also found naturally in aged specialties. The amino-acid tyrosine produces tyramine as part of its natural break down process. It is a part of the normal decay cycle that affects all foods but is especially boosted by aging and fermentation.
The compound is usually assimilated by the digestive system, which has the ability to break it down. As a result, large amounts can't accumulate if the body is healthy.
The main danger of high levels of tyramine is that wrong signals start being sent inside the body. For example, if too much tyramine is present, the neurotransmitter norepinephrine is released in increasing amounts. It might also influence multiple receptors that are associated with head pain and migraines.
Many foods have a content of tyramine, the list includes: wine, aged cheese (like cheddar, brick, and blue cheese), fermented cabbage (also known as sauerkraut), snow peas, fava beans and other types of brad beans, spoiled foods or improperly stored foods, dried and aged meat or fish as well as any varieties that are smoked, fermented or pickled.
Almost all types of cheese include tyramine, for example cottage, cream and Neufch�tel cheeses and ricotta, as well as other dairy products like yogurt and sour cream. It is found in many Asian foods like soy sauce, soybean condiments, teriyaki sauce, tempeh, miso soup, kimchi or shrimp paste. Some of the plants with a content of tyramine are bananas, pineapple, eggplants, figs, red plums, raspberries, peanuts, Brazil nuts, coconuts, yeasts, avocados, mistletoe and most species of cacti.
High levels of tyramine in your body can have many dangerous health consequences and can even be fatal. The most common problem is high blood pressure. If can affect people of any age and it is especially dangerous because it develops slowly, over the course of many years. It is sometimes detected only when it is already too late and can lead to serious conditions like strokes and heart attacks.
The problem is that high blood pressure doesn't have any symptoms sometimes, even when the value has reached dangerous levels. Some possible warnings signs are heartaches, chest pain or accelerated breathing.
Migraines can start both in childhood and during the adult years and are a chronic form of head pain. Men have a lower risk of being affected by migraines, compared to women.
Scientists have been unable to establish the exact cause of migraines so far. However, some factors that increase the risk have been identified. A diet rich in tyramine is one of them, since this compound increases the level of serotonin in the brain by blocking the re-absorption of certain neurotransmitters.
Medication based on monoamine oxidase inhibitor, which is widely used in the treatment of depression, also impair the breakdown of serotonin and can cause migraines. If serotonin is allowed to build up in the brain, the effects can be much more dangerous than a headache.
Migraines usually have a number of symptoms that occur one or two days in advance. These can be depression, increased appetite or a general feeling of fatigue during the daily tasks. There are other possible warning signs as well, for example vomiting, nausea or a persistent headache that only affects one side of the head. Some people also experience blurred vision or a stiff neck.