Misleading: Vitamin E Linked To Lung Cancer

March 31, 2008 · Posted in Wellness, Fitness and Diet

Headlines report “Taking high doses of vitamin E supplements can increase the risk of lung cancer.” Great headline, but the reporting misleads the public. Here is information so you can respond to your patients.

Popular press reported the US study of 77,721 people found that taking 400 milligrams Vitamin E per day long-term increased cancer risk by 28% over a projected 10 year period. This study was published in the March 2008 American Journal of Respiratory Critical Care Medicine by researchers at the University of Washington1 and picked up by the major wire services.

These results could also be stated “Taking high doses of one form of vitamin E, but not other forms, was associated with an increased risk of lung cancer mostly in smokers by a statistically significant, but clinically small factor of 0.0018 - based on an average study risk of 0.0067 (521 / 77721).” I will explain below.

In fact, what was reported in the popular press is not what the researchers wrote in their abstract: “Supplemental vitamin E was associated with a small increased risk of lung cancer (HR, 1.05 for every 100-mg/d increase in dose; 95% confidence interval [CI], 1.00-1.09; P = 0.033). This risk of supplemental vitamin E was largely confined to current smokers (HR, 1.11 for every 100-mg/d increase; 95% CI, 1.03-1.19; P < 0.01).”

8 Vitamin E Isomers

Scientists have known for years that there are 8 isomers (forms) of vitamin E. They are alpha-, beta-, gamma-, and delta-tocopherols and alpha-, beta-, gamma-, and delta-tocotrienols.

Most Vitamin E and multivitamin supplements contain only the alpha-tocopherol isomer. It is the most abundant form in the blood and the least expensive form to produce. It is the form taken by an estimated 99% of the subjects in the study, however the researchers did not ask which form was taken.

It seems that when large doses of the alpha-tocopherol form of vitamin E are available, as from most single or multivitamin supplements, the alpha-tocopherol form displaces the other forms that may be available in food. In 2003, Dr. Han-Yao Huang and Dr. Lawrence J Appel, researchers at Johns Hopkins University, showed that supplementing with alpha-tocopherol only, reduced the plasma level of gamma-tocopherol by 58% and reduced detectible levels of delta-tocopherol from 50% to 13% in 184 human subjects.2

Two studies provide more specific information than this study. Before this study was initiated, the Proceedings of the National Academy of Sciences of the United States of America published a study that showed that gamma-tocopherol reduced cancer cell proliferation, while the alpha-tocopherol form of Vitamin E demonstrated slight to no effect on cancer cells.3 In a Japanese study published in 2006, researchers studied the independent effects of all 8 isomers of vitamin E. In their study, alpha- and gamma-tocotrienols inhibited metastasis (the proliferation (spread) of cancer cells), while the tocopherols had little effect.4

Food Sources of Vitamin E

Food sources of vitamin E provide all 8 isomers of vitamin E, which your body knows how to use in the special ways that call for these exotic (and more expensive) forms of the vitamin. Unfortunately, the food supply is deficient in all isomers of natural vitamin E. Food producers are rewarded for increasing crop yields, keeping down costs, and the look and taste of the food. They enhance the soil with nutrients to make the crops grow faster, look better and increase yields, not to enhance the nutritional value of the food. As a consequence, one would need to eat huge amounts of fruits and vegetables to receive an optimal level of nutrients. The state of our current food supply may fill you up, but not give you all the nutrients your body needs.

Someone has to be concerned with nutritional intake. In all likelihood, that person is you and your patient. And there are alternatives. Sophisticated new supplements provide all 8 isomers of Vitamin E, along with other nutrients that are no longer adequately supplied in food.

Other studies have demonstrated that a single vitamin in isolation is not nearly as effective as a balance of vitamins, such as provided by food or a multivitamin. I thus recommend a balanced diet and a sophisticated multivitamin such as Rejuvenation Science