Fischer 344 rats were inoculated with
fibrosarcoma tumor cells and fed diets containing 5% or 10% (wt/wt)
safflower oil or 10% oil containing
docosahexaenoic acid (DHA). Animals were then treated with
arabinosylcytosine (araC) or saline for six days.
Tumor weights were highest in animals fed 10%
safflower oil and treated with saline, intermediate in animals fed oil containing DHA and 5%
safflower oil and treated with saline, and lowest in araC-treated animals from all diets. Plasma
cholesterol and
triglyceride levels correlated highly with final
tumor size, regardless of diet or treatment group. Animals fed
safflower oil had lower intestinal weights than those fed DHA, which histology demonstrated to be a result of differences in villus height and crypt depth. Substantial loss of bone marrow cells occurred in all dietary groups treated with araC; however, the proportion of granulocyte-macrophage precursors remaining in the DHA animals was higher than in saline-treated animals and twofold higher than in the animals fed 10%
safflower oil and treated with araC. These data suggest that, even in the face of rapid
tumor growth and chemotherapeutic challenge, consumption of a diet rich in DHA can slow
tumor growth, prevent
hyperlipidemia, enhance bone marrow cellularity, and promote intestinal growth compared with a moderate-fat n--6-rich diet.