11 foods not to mix with prescription drugs
Spinach, kale, collard greens, and broccoli are super healthy, but they can make medications to prevent blood clots less effective. Green leafy vegetables are rich in vitamin K, which interacts with warfarin, a common blood thinner (Coumadin). Vitamin K is used by the body to make certain blood clotting factors, while warfarin reduces the action of vitamin K.
Tasha Woodall, associate director of geriatric drug therapy at the Mountain Area Health Education Center in Asheville, North Carolina, often talks about workarounds for patients taking drugs like warfarin. “I often tell people, you really don’t need to avoid eating green leafy vegetables. They’re definitely good for you. But the key is to be consistent.”
Patients taking warfarin regularly have their blood levels monitored. “I’ve certainly taken care of people on warfarin who have been stable for a long time and eat spinach, kale, collard greens at every meal of the day,” says Woodall, who is also an associate professor of clinical training at UNC Eshelman School of Pharmacy. “The problem arises when someone eats a spinach salad every day for a few weeks until the bag of spinach runs out, then goes the next week without eating any.” Instead, predictable consumption allows medications to be adjusted accordingly.