Looks like Vitamins C and E aren’t working like they should.

Easy on the E
Vitamin E, in particular, took a big hit. This was once touted for its antioxidant properties, and diets rich in vitamin E from food sources such as nuts and olives are associated with longevity. The recommended daily allowance is about 15 milligrams or 20 international units (IU). In pill form the dose is often 100 to 400 IUs. Couple this with the fact that vitamin E is fat soluble and lingers in the body for a while, and you’ll see the potential trouble.

In September researchers behind a four-year, $100-million study on selenium and vitamin E for the prevention of prostate cancer, funded largely by the National Cancer Institute, called off the study, telling participants to stop taking their supplements. Neither selenium nor vitamin E did anything to prevent cancer, and there seemed to be slightly more cancers among the men taking 400 IU of vitamin E. (The selenium group had more diabetes.)

By October doctors came to realize that vitamin E pills did nothing for the heart. As detailed in the Journal of the American Medical Association, 400 IU of vitamin E did not prevent cardiovascular disease in the over 14,000 subjects followed in the massive and ongoing Physicians’ Health Study II, run by Harvard University.

The same study found that vitamins E and C, together or solely, did nothing to prevent any type of cancer over the course of 10 years. This was reported last week at the American Association for Cancer Research meeting in Washington, D.C.

Vitamin C for cancer

Meanwhile, researchers at Memorial Sloan-Kettering Cancer Center in New York studied the interaction of vitamin C and cancer cells. Apparently cancer cells love vitamin C as much as healthy cells do. This is why previous studies have shown cancer to worsen in patients taking too much vitamin C.

The researchers found that every chemotherapy drug they tested did not work as well if cells were pretreated with vitamin C. In the cell culture experiments, 30 to 70 percent fewer cancer cells treated with vitamin C were killed depending on the drug tested. Turning to animal studies they found that chemotherapy could keep cancer in check but that tumors grew more rapidly in mice given vitamin C.

The researchers theorize that vitamin C protects cancer cells from drug damage at the mitochondria level. These findings were published in the October 2008 issue of Cancer Research.

According to LiveScience.com

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