Category Archives: Vitamin E

Taking Vitamin E Supplements Increases The Risk For Prostate Cancer

Note that this Vitamin E, the same type and strength used in this study that found taking it increased the risk for prostate cancer, is USP Verified. Less than 1% of dietary supplements are USP Verified. USP does not, however, vouch for a product’s safety or efficacy. The FDA doesn’t either. No regulatory body does.

People are still taking vitamin E supplements, either separately or as part of a multivitamin pill. They should know that this landmark study:

Vitamin E and the Risk of Prostate Cancer, The Selenium and Vitamin E Cancer Prevention Trial (SELECT), Journal of the American Medical Association, 12 October 2011

… found:

“Conclusion: Dietary supplementation with vitamin E significantly increased the risk of prostate cancer among healthy men.”

The study was big (35,533 men from 427 study sites in the United States, Canada, and Puerto Rico), and long (7 years: 2004 to 2011). It was designed to test whether taking vitamin E or selenium would prevent prostate cancer. Epidemiological studies suggested they might. Neither were found to prevent prostate cancer. And in the case of vitamin E, just 400 IU’s/day were found, to many people’s surprise, to increase the risk. The increased risk was statistically significant.

“Results: This report includes 54 464 additional person-years of follow-up and 521 additional cases of prostate cancer since the primary report. Compared with the placebo (referent group) in which 529 men developed prostate cancer, 620 men in the vitamin E group developed prostate cancer (hazard ratio [HR], 1.17; 99% CI, 1.004-1.36, P = .008).”

“The risk of prostate cancer at 7 years of median follow-up was increased by 17% in men randomized to supplementation with vitamin E alone, a difference that started to appear about 3 years after randomization. … The increased rate of prostate cancer in the vitamin E group was seen as early as 2006 and continued until the present analysis (HRs ranged from 1.12 to 1.17) suggesting that the current results are not an outlier observation due to multiple looks at the data.

Despite the lack of a mechanistic explanation, the findings show that vitamin E supplementation in the general population of healthy men significantly increases the risk of being diagnosed with prostate cancer.

This study only looked at prostate cancer. It couldn’t comment on other cancers. And it also couldn’t say if lesser doses were safe. 400 IU’s raises the risk for prostate cancer, but does 200 IU’s? 50 IUs? The following excerpt is going to hinder future studies that try to answer those questions:

“Furthermore, the fact that the increased risk of prostate cancer in the vitamin E group of participants in SELECT was only apparent after extended follow-up (allowing for additional events) suggests that health effects from these agents may continue even after the intervention is stopped.”

You could draw many assumptions from a study like this, and none of them, given this data, would support taking vitamin E supplements.

But this doesn’t stop people from taking vitamin E, “just to be safe” or “as an insurance policy against when I don’t eat right” or “to top off” their diet.  They say taking vitamins doesn’t do any harm and could help.  How do they know there is no harm?  And where is the evidence that these pills help us live longer? Or in better health?

I just came from Dr. Weil’s site, where he continues to advise taking 400 to 800 IUs vitamin E daily and says (as of 29 October 2012, a year after this study was published), in response to the question, “Are there any risks associated with too much vitamin E?” … “Except for an anticoagulant effect, vitamin E has no known toxicity or side effects.”

See my related post: Folic Acid Supplements Increase The Risk For Cancer, Especially Lung Cancer

Antioxidants Including Vitamin E Found To Promote Lung Cancer

VitaminE8Reuters is reporting on a new study that investigated whether antioxidants could fight cancer. Not only did antioxidants not help slow cancer growth, but…

“The antioxidants caused a 2.8-fold increase in lung tumors, made the tumors more invasive and aggressive, and caused the mice to die twice as quickly – all compared to mice not given antioxidants.

When the antioxidants were added to human lung tumor cells in lab dishes, they also accelerated cancer growth.”

Here’s the mechanism:

“What seems to happen is that antioxidants indeed decrease DNA damage, as expected. But the damage becomes so insignificant as to be undetectable by the cell. The cell therefore does not deploy its cancer-defense system.”

The scientists stressed that the results do not pertain to foods such as fruits and vegetables that are naturally high in antioxidants.”

Antioxidants Including Vitamin E Can Promote Lung Cancer: Study, Reuters, 29 January 2014

Co-author of the study, Per Lindahl, said “antioxidants allow cancer cells to escape cells’ own defense system,” letting existing tumors, even those too small to be detected, proliferate uncontrollably.

Here’s the study:

Antioxidants Accelerate Lung Cancer Progression in Mice, Science Translational Medicine, 29 January 2014

“Antioxidants are widely used to protect cells from damage induced by reactive oxygen species (ROS). The concept that antioxidants can help fight cancer is deeply rooted in the general population, promoted by the food supplement industry, and supported by some scientific studies.

We show that supplementing the diet with the antioxidants N-acetylcysteine (NAC) and vitamin E markedly increases tumor progression and reduces survival in mouse models of B-RAF– and K-RAS–induced lung cancer. RNA sequencing revealed that NAC and vitamin E, which are structurally unrelated, produce highly coordinated changes in tumor transcriptome profiles, dominated by reduced expression of endogenous antioxidant genes. NAC and vitamin E increase tumor cell proliferation by reducing ROS, DNA damage, and p53 expression in mouse and human lung tumor cells. Inactivation of p53 increases tumor growth to a similar degree as antioxidants and abolishes the antioxidant effect.

Thus, antioxidants accelerate tumor growth by disrupting the ROS-p53 axis. Because somatic mutations in p53 occur late in tumor progression, antioxidants may accelerate the growth of early tumors or precancerous lesions in high-risk populations such as smokers and patients with chronic obstructive pulmonary disease who receive NAC to relieve mucus production.”

As it stands, smokers are being advised to get more antioxidants, e.g. “Individuals who smoke require 35 mg/day more vitamin C than nonsmokers.” Hm. Best to eat an orange and skip the supplement.

Dr. Campbell described this, in a conceptual way, in his book, “Whole.” When you put a chemical – in isolated, concentrated form – into the chemical soup that is our body, you can’t easily predict how all the other chemicals are going to respond.

Dr. Paul Marantz, epidemiologist at Albert Einstein College of Medicine:

“It’s disappointing but not surprising that people’s beliefs are not modified by scientific evidence. … People so want to believe there is a magic bullet out there.”