In The News: The Interaction Between Herbs and Blood-Thinning Medications

| 7/22/2010 2:47:07 PM

S.CollinsThink twice about pairing herbs with heart medications. A study from the Journal of the American College of Cardiology says that there are about 30 herbal supplements you should avoid if you take blood-thinning medications, such as warfarin.

You can check out the full list of problematic herbs at The list includes herbal favorites, such as garlic, green tea and hawthorn. The study says that when these herbal supplements are taken with blood-thinning medication, it can be hazardous to your health. So let’s break down the more well-known herbs to see what causes the problem.

Garlic is commonly used to lower LDL (bad) cholesterol and blood pressure, and is sometimes used as a blood thinner. But according to the study, the risk of bleeding increases when garlic is mixed with warfarin. This is because the anti-clotting agents prevent wounds from closing.

Garlic Braids
Watch out for the garlic when on heart medication. You shouldn't mix the two.
Photo by CarbonNYC/Courtesy Flickr

Green tea’s antioxidants and vitamins help people lose weight, fight cancer, maintain healthy cholesterol levels and increase their alertness. But, when taken with blood-thinners, the results are not so great. The Health article says that green tea contains vitamin K, which can possibly counteract the effect of warfarin.

Hawthorn is a well known heart-helper; it's because of its heart healing properties that it can cause problems with blood-thinning medication. When hawthorn strengthens heart contractions, it can interact and cause problems with people on heart-failure medications.