Foods to Avoid When Taking an MAOI Antidepressant

Which Foods and Drinks Cause Problems and Why

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Monoamine oxidase inhibitors (MAOIs) were the first type of antidepressant drug developed in the 1950s to treat depression. While they have largely been supplanted by other classes of drug with fewer side effects, MAOIs still have their place in treatment, most notably in people diagnosed with atypical depression.

If you are prescribed an MAOI antidepressant, you would likely need to make changes to your diet to avoid foods that are high in a compound called tyramine. If you don't, the concentration of tyramine in your blood can increase and cause a potentially dangerous spike in blood pressure.

How MAOIs Work

MAOIs are prescribed to help improve mood disorders such as depression. Moods are largely regulated by substances in the brain called neurotransmitters that deliver chemical messages either between nerves cells or between nerve cells and other cells (such as muscle cells).

There are three types of neurotransmitter commonly involved in the regulation of moods known as serotoninnorepinephrine, and dopamine. These neurotransmitters are classified as monoamines because they only contain one amino acid group.

Each has a slightly different function:

  • Serotonin, known as the "feel good" hormone, helps regulate mood, social behavior, appetite, sleep, memory, and sexual desire.
  • Norepinephrine spurs the body and brain to action, increasing alertness, arousal, and the retrieval of memory.
  • Dopamine plays a key role in the brain's "reward" center.

When these and other neurotransmitters have been used, they are destroyed by an enzyme known as monoamine oxidase (MAO). However, if the process is too robust and too many neurotransmitters are destroyed, you may develop symptoms of clinical depression.

MAOIs work by blocking the activity of the MAO enzyme, resulting in higher concentrations of neurotransmitters and an improvement in depression symptoms.

Commonly prescribed MAOIs include Emsam (selegiline), Marplan (isocarboxazid), Nardil (phenelzine), and Parnate (tranylcypromine).

MAOIs and Tyramine

In addition to serotonin, norepinephrine, and dopamine, there is another type of monoamine, called tyramine, which is involved not with mood regulation but with blood pressure.

Under normal circumstances, the MAO enzyme would clear tyramine from the system in the same way it would a used neurotransmitter. However, if you are taking an MAOI antidepressant, the MAO enzyme would be unable to take action on any monoamide, including tyramine.

If this happens and tyramine begins to accumulate, your blood pressure can rise, resulting in hypertension. If it rises to toxic levels, you may experience the potentially life-threatening condition known as a hypertensive crisis.

Symptoms of a hypertensive crisis include

  • Severe headaches
  • Nausea and vomiting
  • Severe anxiety
  • Profuse sweating
  • Nosebleeds
  • Rapid heartbeat
  • Chest pains
  • Changes in vision
  • Shortness of breath
  • Confusion

On rare occasion, a hypertensive crisis may lead to a stroke.

MAOIs and Diet

One of the factors that can lead to an MAOI-associated hypertension is the consumption of foods high in tyramine.

Tyramine is naturally found in small quantities in all protein-containing foods. However, as these foods either age, ferment, or undergo processes like curing, the tyramine levels can increase dramatically. Cooking does not remove tyramine from foods.

People taking MAOI antidepressants are advised to avoid or restrict certain foods that are rich in tyramine, include:

  • Strong or aged cheeses, such as cheddar, Swiss, parmesan, camembert, and blue cheeses such as gorgonzola or Roquefort
  • Alcoholic beverages, especially sherry, red wine, liqueurs, and beers
  • Aged or cured meats, especially salami
  • Cured fish roe and caviar
  • Smoked or processed meats
  • Chicken, beef, or pork liver
  • Meats prepared with chemical meat tenderizers
  • Soy products, including tofu
  • Snow peas and broad (fava) beans
  • Pickled or fermented foods, such as sauerkraut, pickles, kimchee, miso
  • Fermented sauces, such as fish sauce, soy sauce, or shrimp sauce
  • Concentrated yeast extract, brewer's yeast, yeast supplements, or marmite
  • Bread made with a fermented starter, such as sourdough
  • Dried or overripe fruit
  • Any food that is not fresh or close to its expiration date

Other Foods to Watch

While there is no "MAOI diet" per se, there are foods you can eat safely and others you would need to watch. Among the recommendations:

  • Beverages such as milk, carbonated drinks, and decaffeinated coffee or tea are acceptable. However, you should limit your intake of chocolate drinks, white wine, and caffeinated coffee or tea.
  • Breads such as whole wheat and enriched white bread are fine. Restrict your intake of crackers, especially those made with sourdough (such as sourdough eye crisps).
  • Cheeses such as cottage cheese, farmer cheese, cream cheese, ricotta cheese, and processed cheese are safe. Limit your intake of buttermilk, sour cream, and yogurt.
  • Meats, fish, or poultry that are fresh or frozen are fine. Restrict your intake of fresh sausage meat and foods like canned sardines or canned meat.
  • Sweets such as hard candies, cakes, puddings, ice cream, and gelatins are okay. However, limit your intake of chocolate desserts.

While it is important to restrict certain foods while taking an MAOI, always do so by maintaining a healthy, balanced diet with plenty of proteins, carbohydrates, and healthy fats. Generally speaking, a healthy, high-fiber diet with a moderate intake of alcohol will inherently be lower in tyramine than a high-fat, low-fiber one.

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