The influence of dietary levels of vitamin A and fat on colon cancer.
Rats fed diets high (24%) or low (5%) in fat were given dietary levels of vitamin A (retinyl acetate) ranging from 0.3 to 30 micrograms/g food. The lowest tumor incidence was in the group fed diets high in vitamin A and low in fat. When the diet was high in fat and low in vitamin A, tumor incidence and frequency were significantly increased over that in rats fed the high-fat diet with normal levels of vitamin A (10 micrograms/g feed). However, even with a high level of fat in the diet, raising the level of vitamin A above 10 micrograms/g feed had no further beneficial effect. Thus, although there was a significant interaction between vitamin A and fat, it is the latter that appears to require the most attention, once the vitamin A intake is adequate. These data support the view that we should set as a goal an adequate, diversified diet that is low in fat but that an excessive intake of vitamins such as vitamin A that are toxic should be avoided.
Newberne
P M
PM
Department of Pathology, Boston University School of Medicine, MA 02118.
Bueche
D
D
Riengropitak
S
S
Schrager
T F
TF
D000818:Animals; D001835:Body Weight; D003110:Colonic Neoplasms / Q000139:chemically induced* / Q000209:etiology; D004041:Dietary Fats / Q000008:administration & dosage* / Q000009:adverse effects; D004127:Dimethylhydrazines; D004435:Eating; D005526:Food, Formulated; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D014801:Vitamin A / Q000008:administration & dosage* / Q000009:adverse effects; D014802:Vitamin A Deficiency / Q000150:complications
D004041:Dietary Fats; D004127:Dimethylhydrazines; D014801:Vitamin A