Low-carbohydrate diets and prostate cancer: how low is "low enough"?
Previous studies indicate that carbohydrate intake influences prostate cancer biology, as mice fed a no-carbohydrate ketogenic diet (NCKD) had significantly smaller xenograft tumors and longer survival than mice fed a Western diet. As it is nearly impossible for humans to consume and maintain NCKD, we determined whether diets containing 10% or 20% carbohydrate kcal showed similar tumor growth as NCKD. A total of 150 male severe combined immunodeficient mice were fed a Western diet ad libitum, injected with the human prostate cancer cell line LAPC-4, and then randomized 2 weeks later to one of three arms: NCKD, 10% carbohydrate, or 20% carbohydrate diets. Ten mice not injected were fed an ad libitum low-fat diet (12% fat kcal) serving as the reference in a modified-paired feeding protocol. Mice were sacrificed when tumors reached 1,000 mm(3). Despite consuming extra calories, all mice receiving low-carbohydrate diets were significantly lighter than those receiving a low-fat diet (P < 0.04). Among the low-carbohydrate arms, NCKD-fed mice were significantly lighter than the 10% or 20% carbohydrate groups (P < 0.05). Tumors were significantly larger in the 10% carbohydrate group on days 52 and 59 (P < 0.05), but at no other point during the study. Diet did not affect survival (P = 0.34). There were no differences in serum insulin-like growth factor-I or insulin-like growth factor binding protein-3 at sacrifice among the low-carbohydrate arms (P = 0.07 and P = 0.55, respectively). Insulin was significantly lower in the 20% carbohydrate arm (P = 0.03). LAPC-4 xenograft mice fed a low-carbohydrate diet (10-20% carbohydrate kcal) had similar survival as mice consuming NCKD (0% carbohydrate kcal).
Masko
Elizabeth M
EM
Duke University Medical Center, Box 2626, Durham, NC 27710, USA.
Thomas
Jean A
JA
Antonelli
Jodi A
JA
Lloyd
Jessica C
JC
Phillips
Tameika E
TE
Poulton
Susan H
SH
Dewhirst
Mark W
MW
Pizzo
Salvatore V
SV
Freedland
Stephen J
SJ
D000230:Adenocarcinoma / Q000178:diet therapy* / Q000473:pathology; D000818:Animals; D001835:Body Weight / Q000187:drug effects / Q000502:physiology; D050528:Diet, Carbohydrate-Restricted / Q000379:methods; D055423:Diet, Ketogenic / Q000009:adverse effects; D004040:Dietary Carbohydrates / Q000009:adverse effects / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D002149:Energy Intake / Q000502:physiology; D006085:Graft Survival / Q000187:drug effects; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D016513:Mice, SCID; D011471:Prostatic Neoplasms / Q000178:diet therapy* / Q000473:pathology; D047368:Tumor Burden / Q000187:drug effects; D023041:Xenograft Model Antitumor Assays
D004040:Dietary Carbohydrates