The Kurzweil Diet

Mr. Kurzweil, however, recommends far more than the standard preventative counsel to eat a healthier diet and get more exercise. Moderation is not his counsel for the radical reprogramming of the body. For example, Mr. Kurzweil and Dr. Grossman advocate taking large doses of vitamins and minerals and letting your body sort out what it needs - an approach that some experts say is extreme and perhaps risky.

"They have totally bought into mega-dosing on vitamins by accepting scanty evidence too early, before it's been properly evaluated," said S. Jay Olshansky, a professor in the school of public health at the University of Illinois at Chicago.

Mr. Olshansky points to a recent study, by an epidemiologist at Johns Hopkins University, that found taking high doses of vitamin E may slightly increase the risks of dying earlier. "Mega-dosing could be mutagenic; it could cause problems," Mr. Olshansky said. "If you follow Ray and Terry's advice, you could die sooner. Kurzweil is asking people to be guinea pigs."