Antimutagenic properties of various dietary components have been investigated in many studies, in order to find compounds protective against the various steps of carcinogenesis. Indeed, cancer is now the principal cause of death in industrialised countries and treatment is still difficult. Thus, research in prevention is of extreme importance. While, the etiology of most cancers has an environmental component, colon or breast cancers are highly linked to dietary habits (up to 50% of colorectal cancers are due to diet; Riboli et al. 1996). In this context, Boutron et al. (1996) showed inverse correlation between consumption of dairy products and colorectal cancer in France.