Alternate-day fasting reduces global cell proliferation rates independently of dietary fat content in mice.
OBJECTIVE
Cell proliferation rates represent a central element in the promotional phase of carcinogenesis. Modified alternate-day fasting (ADF), i.e., a partial 24-h fast alternated with 24-h ad libitum feeding, reduces global cell proliferation rates on a low-fat (LF) diet. Because the majority of Americans consume a diet that is high in fat, testing the antiproliferative ability of ADF on a high-fat (HF) diet is important in terms of diet tolerability in humans. Accordingly, we examined the effects of 85% restriction on the fast day (ADF-85%) with an LF or HF background diet on proliferation rates of various tissues.


METHODS
In a 4-wk study, male C57BL/6J mice were randomized to one of three groups: 1) ADF-85%-LF, 2) ADF-85%-HF, or 3) control.


RESULTS
Body weights of the ADF mice were similar to that of controls throughout the study. A hyperphagic response (P < 0.001) was noted only in the ADF-85%-LF group ( approximately 55% more food consumed on the feed day than controls). No differences were noted for mean energy intake between ADF groups on feed or fast days. Equivalent reductions (P < 0.01) in epidermal, prostate, liver, and splenic T-cell proliferation rates were observed in both ADF groups versus controls. Plasma insulin-like growth factor-1 levels decreased (P < 0.05) similarly in both ADF groups. Insulin-like growth factor-1 mRNA levels were not affected by either treatment.


CONCLUSIONS
These findings indicate that ADF has an antiproliferative effect over a wide range of fat intakes, which may enhance adherence to ADF in humans.
Varady
Krista A
KA
Department of Nutritional Sciences and Toxicology, University of California at Berkeley, Berkeley, California, USA. kvarady@nature.berkeley.edu
Roohk
Donald J
DJ
Bruss
Mathew
M
Hellerstein
Marc K
MK
D000818:Animals; D001835:Body Weight; D049109:Cell Proliferation; D004041:Dietary Fats / Q000008:administration & dosage*; D002149:Energy Intake; D005215:Fasting / Q000502:physiology*; D006963:Hyperphagia; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D012333:RNA, Messenger / Q000378:metabolism; D013601:T-Lymphocytes / Q000502:physiology
D004041:Dietary Fats; D012333:RNA, Messenger; D007334:Insulin-Like Growth Factor I