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A Third of People With Cancer Use Alternative Medicine. Here’s Why That Could Be Dangerous

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About a third of cancer patients use alternative medicine — but many of them don’t tell their doctors, according to a new research letter published in JAMA Oncology.

Complementary and alternative therapies are those that people use in addition to or instead of traditional medical care. Out of about 3,100 cancer patients who responded to questions about cancer and complementary therapy use through the 2012 National Health Interview Survey, just over 1,000 reported using one or more of these therapies during the prior year, the research letter says. Of these, about a third said they did not tell their doctors that they were using alternative therapies.

That’s potentially a problem, since alternative therapies can come with health risks, especially if people halt conventional treatments to pursue them. And some complementary therapies — like herbal supplements, which were taken by more than a third of the people using alternative methods — are not well-regulated and may interact poorly with conventional treatments like chemotherapy and radiation, doctors warn. High levels of antioxidants can interfere with radiation, for example, and herbal supplements can become dangerous when mixed with certain prescription drugs.

Some alternative therapies, however, are widely recommended by oncologists. Mind-body interventions like yoga, tai chi, meditation and mindfulness, which were each used by about 7% of patients, can keep people fit and energetic as they undergo treatment, reduce the side effects of traditional therapies and improve patients’ sleep, stress and mental health. Many hospitals even have alternative medicine centers that offer these programs.

Aside from supplements and mind-body therapies, people were most likely to turn to chiropractors, osteopaths and massage therapists for alternative interventions. Small numbers also used things like acupuncture, energy therapy or homeopathic treatments. While some research finds that acupuncture can help pain, there’s very little evidence supporting practices like Reiki (energy healing). A large 2015 review of studies on homeopathy found that the practice does not have enough evidence to support its effectiveness.

People who were white, female and younger were more likely than other cancer patients to use complementary therapies, the research letter says.

Patients turn to alternative medicine for many reasons, including “persistent symptoms, psychological distress or to gain a sense of control over their care,” the researchers write. And while some complementary therapies may help with these issues, patients should always discuss their choices with a doctor to ensure they won’t endanger their overall care.

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Write to Jamie Ducharme at jamie.ducharme@time.com