Mixing medications and vitamins can be like mixing friends. Sometimes they just don't get along, and at other times, you're playing matchmaker to future couples.
Let's start with a simple example:
Your cholesterol is high, and your doctor has prescribed Lipitor to bring it down. At the same time, you start taking a multivitamin because you feel stressed and tired. But that could be a bad idea.
Statin drugs like Lipitor block the antioxidant effects of vitamin E, found in multivitamins, and vitamin E interferes with the health benefits of statins. These two guests need separate dinner dates.
Like most busy people, juggling the desire to be healthy while working long hours, you're mixing medications and vitamins and you probably have no idea how they interact with each other. Your doctor may not either. Several studies have found that the attitude toward vitamins and other nutritional supplements is Don't ask, don't tell.
So how do you know when interactions among drugs and supplements will be beneficial, rather than harmful? It's all in the details.
Statins: the most frequently prescribed drugs in the US
Millions of Americans take statins, which are used to reduce cholesterol. Chances are you take one yourself or know someone who does. Perhaps you have seen the ads on TV for blockbuster statins like Lipitor, Crestor and or Zocor. Statins work by blocking a liver enzyme that is needed for cholesterol formation. Extensive research indicates that statins can decrease the rate of heart attacks in people at high risk and may also reduce inflammation in blood vessels. But like all other drugs, statins can have severe side effects, which get worse with increasing dosage. The most common are muscle damage, liver damage and fatigue. About 30,000 Americans have experienced life-threatening statin side effects.
Statins Deplete Coenzyme Q10
Coenzyme Q10 is a vital antioxidant produced in your liver by the same enzyme that produces cholesterol. Muscle cells and nerves are especially sensitive to a deficiency of coenzyme Q10. Depletion of coenzyme Q10 by statins may contribute to their side effects. Diabetics, people with heart disease or those on a low fat diet (which does not supply dietary coenzyme Q10) may benefit from taking coenzyme Q10 if they are taking statins. The existing clinical research may underestimate the need for coenzyme Q10 among statin users, because it's conducted over a period of weeks or months, whereas people who use statins take them for decades.
When supplements Hurt Statins
Vitamin E. Vitamin E supplements can also deplete your body of coenzyme Q10, by increasing its rate of breakdown. The depletion of coenzyme Q10 by statins and vitamin E is likely to be additive. This interaction may explain the scientific data that vitamin E supplements can interfere with the life-saving benefits of statins and increase the severity of heart failure in people with heart disease. High doses of vitamin E (more than 100 international units a day) should not be mixed with statins.
Other supplements that should not be mixed with statins include:
St. John's wort. This herb, used to treat depression, can reduce statin blood levels, impairing effectiveness of treatment. The exception is pravastatin (Pravachol), which is not affected by St. John's wort.
Red yeast rice. The active ingredient in red yeast rice is a natural substance similar to the drug lovastatin. Red yeast rice has the same potential toxicity as statins, including muscle damage and depletion of coenzyme Q10.
When Supplements Help Statins
Phytosterols. Extracted from vegetable oils, phytosterols are similar in structure to cholesterol and interfere with cholesterol absorption from food. At a dose of about 2000 milligrams a day, taken with meals, phytosterols can enhance the cholesterol-lowering effect of statins without increasing statin toxicity.
Berberine. Berberine is a component of several herbs, of which goldenseal is the best known. At a dose of about 800 milligrams a day it can increase the removal of cholesterol from the blood, enhancing the effect of statins. Berberine may also reduce blood sugar in people with type 2 diabetes.
Fish oils. The omega-3 fats found in fish oil reduce blood levels of triglycerides, the major type of fat in your body. High triglyceride levels work together with high cholesterol levels to damage blood vessels, and statins have only a small effect on triglycerides. The key omega-3 fats in fish oil are EPA and DHA. Taking 4 grams (4000 milligrams) of EPA/DHA per day along with a statin drug is now recommended by many physicians for patients with elevations of both cholesterol and triglycerides.
Arginine. L-arginine is an amino acid (a component of protein) that is naturally found in foods like beans and nuts. When combined with statin, supplements of L-arginine (500 milligrams twice a day) produced significant reduction of triglyceride levels. L-arginine by itself has no effect on triglyceride levels.
Niacin (vitamin B3). High doses of niacin (500 to 1500 milligrams per day) raise blood levels of the "good" cholesterol (HDL-C), which prevents cholesterol from being trapped in the walls of your arteries. Niacin is available as both a supplement and a prescription drug and has been shown to enhance the beneficial effects of statins on blood vessels.
And don't forget about food. There's no point in allowing the food you eat to fight the medication you take. The protective effect of statins is enhanced by a diet that is low in saturated fat and naturally high in fiber and omega-3 fats. Eating well can reduce the dose of drug you need and therefore reduce the risk of side effects.
Two components of a healthy diet that need to be watched if you're taking a statin are grapefruit juice and pomegranate juice. Each of these can raise the blood level of statins. If you increase or decrease the amounts of these juices you consume, you may have to change the dose of statin you're taking.