Beta-carotene supplements appear to promote the recurrence of potentially pre-cancerous colon polyps in people who smoke and drink regularly, according to a recent study involving 864 subjects who had colon polyps removed.

Beta-carotene, which is converted to vitamin A in the body, acts as an anti-oxidant, cleaning up cell-damaging substances called free radicals that may promote cancer. This study found that the use of 25-milligrams of beta-carotene per day reduced the occurrence of colon polyps by as much as 44%.

However, for the subjects that drank and smoked, beta-carotene had a negative impact on the body, particularly in its development of cancer. People in this category were twice as likely to develop colon polyps than those taking beta-carotene and not drinking and smoking. Doctors aren’t sure why this happens, but it seems that beta-carotene fuels the cancer in some situations.

Also in the same journal an editorial comment made was that while beta-carotene supplements were linked to a greater risk of polyp recurrence in some study participants, that doesn’t necessarily mean the pills actually promote colon cancer.

First published in the Inside Tract® newsletter issue 138 – July/August 2003
Journal of the National Cancer Institute 2003;95:697-699,717-722.