Chili and chocolate. Maple and bacon. These are just a few examples of incredible food combinations that you might not expect to work well together. However, while you can often combine two foods together for an unexpectedly great result, the same isn’t usually true of many different food and drug combinations. Most people are aware that there are some things you shouldn’t mix, usually because the warning is usually right on the medication label, but there are a few terrible combinations out there that aren’t well-known. Additionally, what many people don’t know is that you don’t have to be taking a prescription medication for it to interact badly with another substance, even another medication. Over-the-counter drugs can be just as likely to cause negative interactions with certain foods as prescription drugs and, in some cases, the effects of either type of interaction can actually be fatal. According to Jack Fincham, a professor at the Presbyterian College School of Pharmacy in Clinton, South Carolina, “This is a big issue and a lot of people aren’t aware of it.” Because so many of these combinations aren’t well known, it’s important to speak with your doctor about any potential interactions a new medication might have with any other substances, whether it’s the smoothie you plan on drinking for breakfast or the migraine pill you take before bed. In some cases, it could just be that a certain combination makes your medicine less effective, while other mixes could actually be causing you harm. Fortunately, the solution could be as simple as a quick change to your diet—well, simple depending on what it is that you’re going to have to cut out. Here’s what you need to know before taking that next pill.
1. Cough Syrup and Limes
Most people have heard that grapefruit can cause a variety of unwanted reactions when taken with certain medications, but did you know that’s true for many different citrus fruits? Thankfully, the standard naval or Valencia orange aren’t typically culprits, but another common citrus fruit is—the lime. Along with Seville oranges and pomelos, limes can react with certain cough medicines by blocking the production of a particular enzyme that breaks down dextromethorphan, a common cough suppressant. This causes the medication to build up within the bloodstream, which can then increase your risk of certain side effects from that medication, according to Mary Ellen Gullickson, a Marshfield Clinic pharmacist in Wisconsin. For dextromethorphan in particular, these side effects can include drowsiness and hallucinations. If you eat limes while taking this type of medication, any of the gnarly side effects you experience could last for at least a day, so it’s best to just avoid the combination altogether.
2. Black Licorice and Heart Medications
Thankfully, there aren’t a lot of people out there who actually enjoy black licorice, but those who do need to be careful if they take certain medications. Digoxin is a medication that is typically given to patients with heart failure and issues with heart rhythm. Black licorice contains a compound called glycyrrhizin which, when combined with digoxin, can lead to an irregular heartbeat—consume enough of the compound and the effects could even be fatal. In addition, the compound can make other medications less effective, including certain types of birth control, pain relievers, and blood-pressure medications. Artificially flavored black licorice candy won’t have any effect, however, so a digoxin user is free to consume this to their heart’s content.
3. Caffeine and Bronchodilators
Bronchodilators, more commonly known as inhalers, are devices that are used to treat a number of different conditions, including asthma and chronic bronchitis. The medication they contain is used to relax the person’s airways during an asthma attack so they can breathe without any obstructions. It should be a no-brainer, but something used to relax your body mixed with something used to energize your body isn’t the best idea. For those that use inhalers for whatever reason, it’s best to avoid caffeine as much as possible, but especially after you’ve taken your medication.
4. Dairy and Antibiotics
When taken with dairy products, certain antibiotics can bind to things like iron and calcium in the dairy and prevent the medicine from being properly absorbed by the body. If the antibiotics you’re taking aren’t fully making their way into your system, they’re not going to be as effective when it comes to fighting an infection and it won’t go away as quickly. Two specific classes of antibiotics, tetracyclines and fluoroquinolones, are most well-known for interacting with dairy, so it’s important to avoid things like milk, yogurt, and cheese two hours before and after you take your medication. Supplements that contain calcium and iron can also have the same effect, so be aware of when you take those, too.
5. Soy and Thyroid Medications
Soy doesn’t necessarily interact with thyroid medication itself, but instead interacts with the actual thyroid gland. Compounds contained within soy can have a wide variety of effects on the thyroid gland, causing it to function either too much or too little, though the exact reason why this happens isn’t well understood at this point. Soy is also considered to be a goitrogen, which means that it can enlarge your thyroid gland to the point that it’s considered a goiter. For people taking thyroid medications, eating too much soy can affect how your body absorbs those medications, even rendering them useless.
6. Smoked Meat and Antidepressants
This one might sound a little strange, but a certain amino acid often found in smoked foods can interact with a specific class of antidepressants called monoamine oxidase inhibitors (MAOIs), which includes medications like Nardil, Emsam, and Parnate. Smoked foods contain tyramine, an amino acid that can interact with these medications and cause an increase in blood pressure that can sometimes be life threatening. Foods that are out? Smoked salmon, summer sausage, aged or smoked cheese, and soy sauce, among others. Fortunately, many newer antidepressants aren’t really affected by tyramine according to Nicole Gattas, and assistant professor at the St. Louis College of Pharmacy just be sure to ask your doctor about your specific medication.
7. Chocolate and Ritalin
Chocolate not only contains caffeine, but it also contains another stimulant called theobromine. For those who take ritalin for conditions like attention deficit/hyperactivity disorder (ADHD), combing a stimulant medication with a food that contains two other known stimulants can easily lead to serious side effects, including extremely erratic behaviors and even seizures. The good news when it comes to coffee and chocolate for those who take ritalin is that you can still have it you may just have to have to test yourself to find out how much you can handle before you start to feel shaky, irritable, or nervous. Every person is different, though, so tread lightly at first.
Apple Juice and Allergy Medication
If allergies have you running for your bottle of Allegra, you’ll need to avoid apple juice for about four hours afterwards, according to Gullickson. Why? When you take this type of medication, your body produces a peptide that helps transport the medication into your bloodstream. Apple juice, however, will prevent this peptide from being produced and prevent the medication from having an effect. In fact, it can make the medication up to 70 percent less effective when it comes to putting a stop to your symptoms. Gullickson also says apple juice can affect other medications that are absorbed using the same peptide, including antibiotics, asthma medications, and thyroid medications.
Cinnamon and Blood Thinners
If you’re taking a blood-thinning medication like warfarin, you might want to skip that morning bowl of cinnamon-dusted oatmeal, as delicious as it may be. Well, depending on what kind of cinnamon you have, that is. Cassia cinnamon is rich in a compound called coumarin that also acts as a blood-thinner, and it can lead to excessive bleeding when it’s mixed with a blood-thinning medication. Eric Newman, M.D. of Baltimore’s Mercy Medical Center recommends that anyone taking this type of medication use only Ceylon cinnamon, which contains far less coumarin than cassia cinnamon. Ceylon cinnamon might be a little bit harder to find than cassia, but it’ll be worth the search if you just can’t give it up.
Grapefruit and Statins
Statins are a type of prescription drug that are typically used to lower cholesterol. They work by preventing your body from making cholesterol and helping the body to reabsorb what cholesterol it already has. For those who take two specific statins, Zocor and Lipitor, it’s important to avoiding eating grapefruit or drinking grapefruit juice. Grapefruit contains furanocoumarin, a chemical compound that can prevent the body from absorbing statins, which means that they stay in your bloodstream longer. When this happens, it makes them less effective and can also cause side effects like digestive issues, liver damage, and high blood sugar levels.
Bananas and ACE Inhibitors
Angiotensin-converting-enzyme (ACE) inhibitors are a type of drug that treat certain heart conditions, mostly congestive heart failure and hypertension. These medications can cause an increase in your potassium levels, which can eventually cause someone to have an irregular heartbeat or develop heart palpitations. For anyone taking this type of medication, it’s important to avoid eating too many foods that are known to be high in potassium, one of the most common being bananas. Other foods to avoid include oranges, salt substitutes, sports drinks, and leafy greens.
Kale and Blood Thinners
We can understand why someone might want to add a daily kale smoothie into their diet, but make sure to have a talk with your doctor first if you use blood thinners. Kale is touted as the king of all superfoods, so you might not imagine that there are any downsides to eating it. However, anyone who takes blood-thinning warfarin should stick to romaine lettuce in their salads, because kale could make the medication less effective. In addition to kale, foods like broccoli, Brussels sprouts, spinach, and cabbage contain large amounts of vitamin K, which can interact with warfarin and make it less effective at thinning the blood. Depending on your condition, this could lead to severe complications, including blood clots.
Walnuts and Thyroid Drugs
Walnuts are another great-for-you food that aren’t so great when mixed with certain thyroid medications. Walnuts are fairly high in fiber, which most people would consider to be a pretty great benefit. However, high-fiber foods can prevent your body from absorbing thyroid medications like levothyroxine, meaning that you’ll need more of the drug for it to be effective. Other high-fiber foods that can cause a similar effect include soy flour and cottonseed meal. For those who need thyroid medications but aren’t too keen on changing their diets, studies suggest that the medications will be better absorbed if you take them before bed, rather than taking them in the morning before eating.
St. John’s Wort and Various Medications
Supplements can interact with different medications just as food and drinks can, and St. John’s Wort is one that can cause negative interactions with a few different substances. When mixed with certain antidepressants, migraine medications, and over-the-counter cough medications, St. John’s Wort can cause a dangerous condition called serotonin syndrome. When it’s severe, serotonin syndrome can cause extreme symptoms including confusion, drastic changes in blood pressure, seizures, unconsciousness, and even death. Along with St. John’s Wort, it’s important to tell your doctor about any supplements you are taking before you begin taking a new medication to avoid any serious complications.