Tufts University scientists have found that, when volunteers with high cholesterol levels switched to a low-fat diet, they not only lost weight, but significantly enhanced their immunity, an important factor in cancer prevention. Ten participants were initially instructed to follow a standard American-style diet deriving 35 percent of calories from fat. Then they followed three subsequent diets: one made up of 26 percent fat, one made up of 15 percent fat, and lastly, a 15 percent fat diet with a further reduction in calories. Each diet drove cholesterol levels down, but only the last phase was associated with marked improvement in cellular immune response.
Santos MS, Lichtenstein AH, Leka LS, Goldin B, Schaefer EJ, Meydani SN. Immunological effects of low-fat diets with and without weight loss. J Am Coll Nutr. 2003;22:174-82.
Bingham SA, Day NE, Luben R, et al. Dietary fibre in food and protection against colorectal cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC): an observational study. Lancet. 2003;361:1496-501.