Oil and water, toothpaste and orange juice—some things just don't go together.
But, while you're not likely to get sick from downing a glass of OJ after brushing your teeth, other, seemingly safe, combinations can be harmful.
Take for example, nutritious foods and prescription medications. Seems like a match made in healthful heaven, right?
According to Stephen Dahmer, M.D., of the Continuum Center for Health and Healing, food and drinks can affect how much of a medication gets absorbed into the body and how fast it gets metabolized. These interactions can render a prescription ineffective, or increase the risk of experiencing dangerous side effects.
Wholesome foods may have unwholesome effects
It can be hard to spot an imperfect food-prescription pairing.
Here's a list of five healthy foods that can interact dangerously with common prescriptions:
- Grapefruit juice: Vitamin C, fiber and potassium are just a few of the health perks of grapefruit juice. However, just one glass of grapefruit-y goodness can interfere with important intestinal enzymes, making it easier for some 85 different prescriptions to enter the blood stream, including: statins (Lipitor, Mevacor, Zocor), immunosuppressants, calcium-channel blockers (Plendil, Sular, Procardia), and benzodiazepines (Valium, Triazolam, Halcion). Dahmer says that this may increase the risk of experiencing side effects from these medications. Kelly O'Connor, R.D., of Mercy Medical Center, warns that certain sodas (Squirt, Fresca, etc.) can also contain grapefruit juice, so it's important to check the labels of these beverages closely. She also offers a straightforward solution for obtaining the health benefits of grapefruit without the risk: swap it with another sour citrus—the orange. Orange juice offers similar advantages, without the risk.
- Bananas: A potassium powerhouse, the banana is typically a good choice for those seeking to reduce their risk of cancer, stroke and heart disease. However, eating too many potassium-rich foods (bananas, oranges and green, leafy vegetables) can be problematic if a person is taking ACE inhibitors. Designed to lower blood pressure, these medications also elevate the levels of potassium in the body. According to the FDA, people taking ACE inhibitors (Lotensin, Capoten, Zestril, etc.) may develop dangerous heart palpitations if they over-indulge on foods that are high in potassium. Bananas also contain Tyramine, an amino acid (also found in red wine, soy and certain cheeses) that can negatively interact with MAO inhibitors (Nardil, Parnate)—commonly prescribed to treat depression. O'Connor says that a low-Tyramine diet is typically recommended for people taking MAO inhibitors.
- Cranberry juice: A go-to natural remedy for urinary tract infections, cranberry juice contains chemicals that may dangerously amplify the effect of Lipitor and other statin medications, according to recent research.
- Spinach: Along with its cruciferous cousin—broccoli—spinach receives high praise in health food circles for its vitamin K content and minimal calorie count. But, for people taking blood thinners, including warfarin (Coumadin), munching on too much green can be bad. Dahmer warns that foods high in vitamin K—praised for its ability to promote blood clotting—may nullify the blood-thinning benefits of anti-coagulants. This doesn't mean that going on blood thinners means that you have to forgo your favorite spinach salad. According to O'Connor it's okay for people on these medications to consume a moderate amount of spinach (for example: a one-half cup serving, two to three times a week).
- High-fiber foods: Dietary fiber, the kind found in whole grains, vegetables, and fruits, is a nutritional powerhouse. Fiber has been proven to play a role in reducing a person's risk of heart disease and diabetes. It can also help relieve constipation and promote healthy weight management. But, because fiber slows the rate at which the stomach empties, Dahmer cautions that it may also slow the rate at which medications are absorbed into the blood stream as well, resulting in lower-than-anticipated blood levels of certain prescriptions, such as antibiotics.
You don't always have to swear off a particular food (or food group) just because it may interact with your medications.
Talk to your doctor if you have concerns about how your diet may impact your prescriptions and be sure to thoroughly read the labels on all medications to learn what foods to avoid.
One last tip, offered by Dahmer: take medications with plenty of water to help aid absorption and reduce stomach upset.