Vitamin C can impede the growth of some types of tumors although not in the way some scientists had suspected, researchers reported on Monday. The new research, published in the journal Cancer Cell, supported the general notion that vitamin C and other so-called antioxidants can slow tumor growth, but pointed to a mechanism different from the one many experts had suspected. The researchers generated encouraging results when giving vitamin C to mice that had been implanted with human cancer cells -- either the blood cancer lymphoma or prostate cancer. Another antioxidant, N-acetylcysteine, also limited tumor growth in the mice, the...