Abstract
BackgroundThe role of dietary restriction regimens such as caloric restriction, ketogenic diet and intermittent fasting in development of cancers has been detected via abundant preclinical experiments. However, the conclusions are controversial. We aim to review the relevant animal studies systematically and provide assistance for further clinical studies.MethodsLiteratures on associations between dietary restriction and cancer published in PubMed in recent twenty years were comprehensively searched. Animal model, tumor type, feeding regimen, study length, sample size, major outcome, conclusion, quality assessment score and the interferential step of cancer were extracted from each eligible study. We analyzed the tumor incidence rates from 21 studies about caloric restriction.ResultsFifty-nine studies were involved in our system review. The involved studies explored roles of dietary restriction during initiation, progression and metastasis of cancer. About 90.9% of the relevant studies showed that caloric restriction plays an anti-cancer role, with the pooled OR (95%CI) of 0.20 (0.12, 0.34) relative to controls. Ketogenic diet was also positively associated with cancer, which was indicated by eight of the nine studies. However, 37.5% of the related studies obtained a negative conclusion that intermittent fasting was not significantly preventive against cancer.ConclusionsCaloric restriction and ketogenic diet are effective against cancer in animal experiments while the role of intermittent fasting is doubtful and still needs exploration. More clinical experiments are needed and more suitable patterns for humans should be investigated.
Highlights
Cancer was the second leading cause of mortality worldwide and its incidence has been increasing during the last decades [1, 2]
Caloric restriction and ketogenic diet are effective against cancer in animal experiments while the role of intermittent fasting is doubtful and still needs exploration
Western diet aTime: Time of study; bC: Conclusion of the study, ‘‘+’’ indicates a positive conclusion and ‘‘-’’ represents a negative conclusion; cQ: Quality of the study according to a critical checklist of the Stroke Therapy Academic Industry Roundtable; dS: The step(s) of cancer that dietary restriction regimens interfere during the initiation, progression and metastasis of cancer, ‘‘I’’ indicates initiation, ‘‘P’’ indicates progression and ‘‘M’’ indicates metastasis; eTP: transplanted; fC: carbohydrate; g KC: a nutritionally balanced and commercially available ketogenic diet; h SD: standard diet; i KD: ketogenic diet; j/: not specified; kNCKD: no-carbohydrate ketogenic diet
Summary
Cancer was the second leading cause of mortality worldwide and its incidence has been increasing during the last decades [1, 2]. Among various dietary restriction regimens, caloric restriction (CR), intermittent fasting (IF) and carbohydrate restriction/ketogenic diet (KD) are the most studied methods that are beneficial for cancer prevention. The role of dietary restriction regimens such as caloric restriction, ketogenic diet and intermittent fasting in development of cancers has been detected via abundant preclinical experiments. Tumor type, feeding regimen, study length, sample size, major outcome, conclusion, quality assessment score and the interferential step of cancer were extracted from each eligible study. The involved studies explored roles of dietary restriction during initiation, progression and metastasis of cancer. About 90.9% of the relevant studies showed that caloric restriction plays an anti-cancer role, with the pooled OR (95%CI) of 0.20 (0.12, 0.34) relative to controls. 37.5% of the related studies obtained a negative conclusion that intermittent fasting was not significantly preventive against cancer
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
