The do's and don'ts when taking medications can be confusing, but there are good reasons for your doctor's orders. If you're taking a monoamine oxidase inhibitor (MAOI), it's important to avoid foods high in tyramine, as the interaction could raise blood pressure to dangerously high levels.
Tyramine and MAOIs
Tyramine is a monoamine compound found naturally in some foods and also produced in foods when they are fermented, aged or spoiled, notes Vanderbilt University. This compound may increase blood pressure, but your body has a built-in system for breaking down and excreting excess tyramine. An enzyme called monoamine oxidase that is located in the nerve endings, the brain and the gut protects against the buildup of tyramine and other monoamines.
Monoamine oxidase also breaks down neurotransmitters in the brain, including dopamine, serotonin and norepinephrine and helps remove them from the body, according to the Mayo Clinic. This can become problematic when production of these substances is already hindered, as it is in conditions like depression and Parkinson's disease.
MAOIs slow the breakdown of these neurotransmitters, which may help improve the symptoms of depression and Parkinson's. However, they can also slow the breakdown of tyramine, which may cause it to build up in the bloodstream. When this happens, blood pressure can reach dangerously high levels, causing a "hypertensive crisis." Symptoms of a crisis may include severe headache, blurred vision, seizure, chest pain, difficulty thinking, nausea, vomiting and symptoms or signs of a stroke.
Even 6 to 8 milligrams of tyramine can trigger adverse reactions, including increased blood pressure, nausea and a fast heartbeat, according to Vanderbilt University. Ten to 25 milligrams may cause headaches and potential bleeding in the brain. Intakes over 25 milligrams may lead to a hypertensive crisis.
Read more: 8 Surprising Things Giving You a Headache
Tyramine Foods List
To prevent these side effects, it's crucial for people taking MAOIs to avoid foods high in tyramine. It's a good idea to prepare a tyramine food list that you can keep on hand at all times for reference to prevent inadvertently consuming too much.
In a low-tyramine or tyramine-free diet, you should avoid:
- Strong and aged cheeses, including stilton, which has 33 to 61 milligrams of tyramine per ounce; camembert, with 38 milligrams per ounce; and bleu cheese, with 28 milligrams per ounce, according to Vanderbilt University.
- Cured, smoked and processed meats, such as salami, which has 1.2 to 5.4 milligrams of tyramine in 1 ounce; and dry sausages, which may contain 3 to 43 milligrams per ounce.
- Pickled and fermented foods, including pickled herring in brine, with up to 86 milligrams per ounce; and sauerkraut, with 3.5 to 14 milligrams per ounce.
- Sauces, including soy sauce, which has up to 4.7 milligrams per teaspoon; and fish sauce, which has up to 3.7 milligrams per teaspoon.
- Alcoholic beverages, especially draft beer, which may contain up to 38 milligrams of tyramine in 12 ounces.
Other foods high in tyramine include yeast extracts, snow peas, fava beans, soy beans, dried and overripe fruit and meat tenderizers. It's also important to avoid eating foods that are spoiled or that have been improperly stored.
Some foods and beverages should only be consumed occasionally:
- American and pasteurized cheeses, parmesan, havarti, farmers cheese and brie
- Red or white wine, bottled or canned beer
- Pepperoni, wild game meat, anchovies, snails
- Canned figs
University of Wisconsin Health warns that high-tyramine foods should be avoided/limited while taking the medication and for two weeks after stopping it.
Read more: 10 Healthiest Cheese Types and Brands
The good news is that there are plenty of low-tyramine foods and beverages you can consume regularly. Some examples from each category include:
- Dairy: yogurt, milk and ice cream
- Meat, poultry, fish and eggs: Should be consumed on the day purchased, stored in the freezer or canned. Eggs should be eaten directly after being cooked.
- Beans and peas, except for those listed above.
- All fresh, frozen or canned fruits and vegetables, except those listed above.
- Condiments: ketchup, Worcestershire, mustard, salad dressing
- Coffee, tea, soft drinks
- Yeast bread
- Liquor: gin, vodka, rum, bourbon
If you have any doubt about whether or not a food contains too much tyramine, leave it on the plate and check with your doctor first. If you don't know whether a piece of fresh food is expired or still safe to eat, don't take unnecessary risks.