Effects of a low-fat, high-fiber diet and exercise program on breast cancer risk factors in vivo and tumor cell growth and apoptosis in vitro.
The present study investigated the effects of a diet and exercise intervention on known breast cancer (BCa) risk factors, including estrogen, obesity, insulin, and insulin-like growth factor-I (IGF-I), in overweight/obese, postmenopausal women. In addition, using the subjects' pre- and postintervention serum in vitro, serum-stimulated growth and apoptosis of three estrogen receptor-positive BCa cell lines were studied. The women where placed on a low-fat (10-15% kcal), high-fiber (30-40 g per 1,000 kcal/day) diet and attended daily exercise classes for 2 wk. Serum estradiol was reduced in the women on hormone treatment (HT; n = 28) as well as those not on HT (n = 10). Serum insulin and IGF-I were significantly reduced in all women, whereas IGF binding protein-1 was increased significantly. In vitro growth of the BCa cell lines was reduced by 6.6% for the MCF-7 cells, 9.9% for the ZR-75-1 cells, and 18.5% for the T-47D cells. Apoptosis was increased by 20% in the ZR-75-1 cells, 23% in the MCF-7 cells, and 30% in the T-47D cells (n = 12). These results show that a very-low-fat, high-fiber diet combined with daily exercise results in major reductions in risk factors for BCa while subjects remained overweight/obese. These in vivo serum changes slowed the growth and induced apoptosis in serum-stimulated BCa cell lines in vitro.
Barnard
R James
RJ
Department of Physiological Science, University of California, Los Angeles, Los Angeles, CA 90095-1606, USA. jbarnard@physci.ucla.edu
Gonzalez
Jenny Hong
JH
Liva
Maud E
ME
Ngo
Tung H
TH
D000368:Aged; D017209:Apoptosis; D001943:Breast Neoplasms / Q000097:blood*; D002455:Cell Division; D045744:Cell Line, Tumor; D018752:Diet, Fat-Restricted; D004041:Dietary Fats / Q000008:administration & dosage*; D004043:Dietary Fiber / Q000008:administration & dosage*; D004958:Estradiol / Q000097:blood; D004967:Estrogens / Q000097:blood; D015444:Exercise / Q000502:physiology*; D005260:Female; D020249:Hormone Replacement Therapy; D006801:Humans; D007328:Insulin / Q000097:blood; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008875:Middle Aged; D009765:Obesity / Q000097:blood / Q000628:therapy; D017698:Postmenopause / Q000097:blood; D012307:Risk Factors
D004041:Dietary Fats; D004043:Dietary Fiber; D004967:Estrogens; D007328:Insulin; D018970:Insulin-Like Growth Factor Binding Protein 1; D004958:Estradiol; D007334:Insulin-Like Growth Factor I