A team led by Qing Jiang (pronounced "ching zhang") has found that gamma-tocopherol, which occurs naturally in walnuts, pecans, sesame seeds, and in corn and sesame oils, inhibits the proliferation of lab-cultured human prostate and lung cancer cells. The vitamin's presence interrupts the synthesis of certain fatty molecules called sphingolipids, important components of cell membranes. However, the gamma-tocopherol leaves healthy human prostate cells unaffected, which could give it value as an anticancer agent.
"This is the first time gamma-tocopherol has been shown to induce death in lab-grown human cancer cells while leaving healthy cells alone," said Jiang, who is an assistant professor of foods and nutrition in the College of Consumer and Family Sciences. "This could be wonderful news for cancer patients if the effect can be reproduced in animal models. But because most nutritional supplements contain only alpha-tocopherol, a different form of vitamin E that alone does not have these anticancer properties, it may be better to supplement the diet with mixed forms of vitamin E. The study shows that the anticancer effect is enhanced when mixed forms are used."
Jiang's research appears in the current (week of Dec. 13) online edition of the scientific journal Proceedings of the National Academy of Sciences. She co-authored the paper with Jeffrey Wong, Henrik Fyrst, Julie D. Saba and Bruce N. Ames of the Children's Hospital Oakland Research Institute in Oakland, Calif.
Scientists have been studying vitamin E for more than three-quarters of a century, but most efforts have focused largely on alpha-tocopherol, one of eight known forms in the vitamin's family. Alpha-tocopherol was found early on to have the mo
Contact: Chad Boutin