The results of a new study suggest that a high fat diet, while not likely to cause breast cancer, may play a supporting role, Reuters Health reported this week. Researchers at the London School of Hygiene and Tropical Medicine examined "all relevant epidemiological and biological evidence" relating to the development of breast cancer. As a result they suggest that dietary fat is not the causal agent but instead causes depletion of an essential agent that is normally protective against breast cancer. Scientists further proposed that a deficiency of this as yet undiscovered agent, either by inadequate intake or depletion via a high fat diet, working in tandem with age and estrogen, permits breast cancer to develop. The findings are published in the November issue of the Journal of Epidemiology and Community Health.