American Journal of Clinical Nutrition, Vol 66, 1539S-1540S, Copyright © 1997 by The American Society for Clinical Nutrition, Inc

REVIEW ARTICLES

Animal studies: summary, gaps, and future research

MW Pariza
Department of Food Microbiology and Toxicology, University of Wisconsin- Madison 53706, USA. mwpariza@facstaff.wisc.edu

Animal models are essential in cancer research but investigators should recognize the limits of the models they use. Because there is no ideal animal model, researchers should use the biological and biochemical diversity among the models to experimental advantage. The differences can tell us as much as the similarities. Fatty acid metabolism seems to play a role in hormone-dependent and hormone-independent cancers, and cell culture experiments have yielded much information on possible mechanisms. However, a knowledge gap exists between these studies and a full understanding of mechanisms in vivo. Mechanisms must be understood before the possible relevance of the findings to humans can be confidently assessed. There is little evidence to suggest that either trans fatty acids or oleic acid has any specific effect on carcinogenesis and it is unlikely that further study will reveal something important but heretofore overlooked. By contrast, there appear to be notable gaps in our understanding of n-3 fatty acids, linoleic acid, and conjugated linoleic acid in relation to possible effects on cancer in humans. The major knowledge gap, and our greatest challenge, is relating promising data from animal models and cell culture studies to the prevention of cancer in humans.