A healthy diet full of vitamin-packed fruits and vegetables is known to be one good way to lower your risk of cancer. But, so far, studies into the role of vitamins in helping people who have cancer to beat it have generated mainly inconclusive evidence. Now, a new study shows a promising role for vitamin C, in women with endometrial tumours at least, and what’s more a mechanism that might explain its effect. Researchers from the University of Otago have found the first real evidence of a connection between vitamin C and tumour growth. Lead researcher associate professor Margreet Vissers and her colleagues found tumours were less able to accumulate vitamin C compared with normal healthy tissue, and this related to the ability of the tumour to survive and grow. Tumours with low vitamin C levels had more of a protein called HIF-1, which allows them to thrive in conditions of stress. The findings, reported in the 15 July 2010 issue of Cancer Research, are significant as they show, for the first time, a direct relationship between HIF-1 and vitamin C levels in tumours. They suggest it would be beneficial for people with cancer cells to have more vitamin C to possibly help limit the rate of growth, increase response to chemotherapy and perhaps prevent the formation of solid tumours.