The interaction of a high-fat diet and regular moderate intensity exercise on intestinal polyp development in Apc Min/+ mice.
Diet and exercise are two environmental factors that can alter colon cancer risk. The purpose of this study was to determine if regular moderate-intensity treadmill exercise training could attenuate polyp formation in Apc(Min/+) mice fed the Western-style diet. Four-week-old male Apc(Min/+) mice (n = 12 per group) were assigned to AIN-76A Control, AIN-76A Exercise, Western Control, or Western Exercise treatment groups. Mice were weaned to these diets and either subjected to regular moderate-intensity treadmill exercise (18 m/min, 60 min/d, 6 d/wk) or remained sedentary for 6 weeks. Mice fed the Western-style diet consumed approximately 14% more calories and had 42% more epididymal fat compared with mice fed the AIN-76A diet. Exercise had no effect on fat pad mass with either diet treatment. Exercise reduced total intestinal polyp number by 50% and the number of large polyps (>1 mm diameter) by 67% in AIN-76A-fed mice. The Western-style diet increased polyp number by 75% when compared with AIN-76A-fed mice, but exercise did not decrease polyp number or alter polyp size in mice fed the Western-style diet. Markers of systemic inflammation and immune system function were improved with exercise in mice fed the AIN-76A diet. Mice fed the Western-style diet showed more inflammation and immunosuppression, which were not completely ameliorated by exercise. These data suggest that the induction of adiposity, inflammation, and immunosuppression by the Western-style diet may compromise the beneficial effect of moderate-intensity exercise on the intestinal polyp burden in Apc(Min/+) mice.
Baltgalvis
Kristen A
KA
Department of Exercise Science, University of South Carolina, 921 Assembly Street, Columbia, SC 29208, USA.
Berger
Franklin G
FG
Peña
Maria Marjorette O
MM
Davis
J Mark
JM
Carson
James A
JA
D000818:Animals; D001835:Body Weight; D003110:Colonic Neoplasms / Q000235:genetics*; D015179:Colorectal Neoplasms; D004032:Diet; D005260:Female; D007165:Immunosuppression Therapy; D007249:Inflammation; D007417:Intestinal Polyps / Q000473:pathology* / Q000517:prevention & control; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D010805:Physical Conditioning, Animal; D011127:Polyps