Researchers uncover risks of some herbal medicines for cancer patients

The study published in the journal Cancer concludes that herbal remedies such as turmeric may increase the toxic effects of certain chemotherapies, while gingko biloba and green teas could increase the risks of bleeding in some cancer patients. Other herbs including black cumin and turmeric can alter the effectiveness of chemotherapy.

The study focused on cancer patients in the Middle East. In all, 29 of the 44 most popular herbal medicines used in 16 Middle Eastern countries -- from Turkey to Tunisia -- could pose one or more health risks to cancer patients in the region.

"In the Middle East, herbs are commonly used as part of traditional medicine, based on the impressive affinity of the people here to the herbal heritage that continuously prospers from the time of ancient Egypt and Mesopotamia," Ben-Arye said.

The findings come from a survey conducted by Ben-Arye and colleagues, who asked more than 300 cancer care providers in the countries about the kinds of herbal medicines their patients were using. They found that 57% of the providers had patients who used at least one herbal remedy. Women and Muslim providers were more likely to report having patients who used the herbs.

Although many patients use the herbs without telling their physicians, in this study Ben-Arye and colleagues wanted to focus on cancer care providers who are aware of their patients' herbal supplement use. In general, Middle Eastern cancer care providers have a skeptical view of these alternative medicines, Ben-Arye said. However, his studies show that the providers also support the idea of having a physician consultant on a patient's cancer care team who can speak to the "the effectiveness and safety of these herbal practices along with conventional cancer treatments," he noted.

Patients feel similarly, Ben-Arye suggested. "In the majority of cases, patients seek to combine the best of the two worlds and do not perceive herbal medicine as a real alternative to modern oncology care."

Patients most often turn to the herbs to enhance their quality of life and to cope better with the effects of their treatment, Ben-Arye added, rather than use them in an attempt to cure their cancers.

The countries in the survey with the highest rates of herbal medicine use included Turkey, the Palestinian Authority and Qatar. Stinging nettle, garlic, black cumin and turmeric were among the most used herbs, with other items such as camel's milk and honey also making the list.

The researchers hope the new study will guide cancer care providers as they offer "open, non-judgmental" advice about the safety and effectiveness of herbal medicines.

"The majority of patients would hope to share their experience and questions of herbal option with their health care provider 'at home' within the oncology department rather than 'outside' where non-professionals and sometimes charlatans suggest miraculous potions," Ben-Arye said.