October 15, 2012

187 Vitamin E & Liver Cancer [15 October 2012]

Finally some good news about Vitamin E! It has been getting a lot of bad press lately, most of it undeservedly – like the study I wrote about a few months ago in column #176 which found that synthetic E raised the risk of prostate cancer.

Part of the Shanghai Men’s and Women’s Health Studies, run from 1997 to 2006 and published in July 2012 in J. National Cancer Inst., looked at liver cancer risk in middle-aged and older adults with differing vitamin intakes. They found that both dietary and supplementary vitamin E intake was inversely associated with liver cancer risk. This held true for participants both with, and without, existing liver disease or family history of liver cancer. And the results were dose dependent, meaning the more E ingested, the lower the risk. This finding agrees with previous studies which showed vitamin E is protective of the liver; it is even used as a treatment for nonalcoholic fatty liver disease (NAFLD).

Disturbingly though, it also found that for those with an existing liver disease or family history of liver cancer, high intake of vitamin C from supplements (but not from food) increased the risk of liver cancer. This is a surprise because Vitamin C has long been thought to be protective from cancer. A 1991 review published in the Am. Soc. Clinical Nutrition found that in 33 of 46 studies examined, vitamin C provided a significant protection from various cancers. But a 10 year clinical trial – the Physicians Health Study II – published in 2008 found that 400iu of E or 500mg of C did not reduce the risk of cancers, but also did not cause any harm. I would consider both doses to be low, and the E was undoubtedly pure alpha-tocopherol with no gamma-tocopherol, known from another study to significantly reduce the risk of prostate cancer.

Because of inconsistent study results like these medical scientists are reluctant to make dietary recommendations based on one or two studies.

Back to vitamin E. There are two families of E – four tocopherols and four tocotrienols – each with their own physiological functions. The best E supplement has all 8 vitamin Es, and uses the natural d not the synthetic dl forms. For more detail on this interesting vitamin family, see my December 2011 column #143.

For more information on this or other natural health topics, stop in and talk to Stan; for medical advice consult your licensed health practitioner.

1 comment:

  1. Good post. Sometimes I wonder how some of these papers make it past the review stage or even how they get past the design stage.