Cancer patients should tell their doctors if they are taking herbal products because some of the ingredients could stop their therapy working, a cancer meeting has heard.
Garlic, ginger and ginkgo pills, for example, can delay the healing of skin wounds when breast cancer spreads.
Surgeon Prof Maria Joao Cardoso, said there was no evidence that herbal therapies or creams worked.
If in doubt, it was best not to take anything, she said.
“Doctors need to be more proactive about asking their patients what else they are taking when they are being treated for cancer, ” Prof Cardoso, head breast surgeon at the Champalimaud Cancer Centre in Lisbon, Portugal, told the BBC.
She said it was particularly important that patients always checked with their doctors first before trying complementary therapies for cancer that had spread to the skin.
This happens in one in five cases of breast cancer – and reductions in other cancers.
The danger is that many products can interfere with hormone therapy or chemotherapy therapies, and certain ones prolong the blood clotting process – which can lead to wounds taking longer to heal and more scarring.
She highlighted the following herbal products as examples of those which slow down clotting 😛 TAGEND green chiretta feverfew garlic ginkgo ginseng hawthorn pony chestnut turmeric Image caption