Intermittent fasting in the prevention and treatment of cancer

Abstract

Chronic caloric restriction (CR) has powerful anticarcinogenic actions in both preclinical and clinical studies but may be difficult to sustain. As an alternative to CR, there has been growing interest in intermittent fasting (IF) in both the scientific and lay community as a result of promising study results, mainly in experimental animal models. According to a survey by the International Food Information Council Foundation, IF has become the most popular diet in the last year, and patients with cancer are seeking advice from oncologists about its beneficial effects for cancer prevention and treatment. However, as discussed in this review, results from IF studies in rodents are controversial and suggest potential detrimental effects in certain oncologic conditions. The effects of IF on human cancer incidence and prognosis remain unknown because of a lack of high-quality randomized clinical trials. Preliminary studies suggest that prolonged fasting in some patients who have cancer is safe and potentially capable of decreasing chemotherapy-related toxicity and tumor growth. However, because additional trials are needed to elucidate the risks and benefits of fasting for patients with cancer, the authors would not currently recommend patients undergoing active cancer treatment partake in IF outside the context of a clinical trial. IF may be considered in adults seeking cancer-prevention benefits through means of weight management, but whether IF itself affects cancer-related metabolic and molecular pathways remains unanswered.

Metabolomics and the Multi-Omics View of Cancer

“…For instance, depleting dietary glucose (a key oncometabolite) through low carbohydrate, ketogenic diets has been shown to have positive effects in patient survival, tumor sensitization, and tumor shrinkage [13,193]. Similarly, caloric restriction, intermittent fasting, or the deprivation of certain "oncogenic" amino acids in the diet has also been shown to have positive effects in cancer for various animal models and in some cancer patients [194][195][196][197]. Likewise, the addition of certain basic compounds (such as bicarbonate, lysine, or Tris) in the diet to buffer against the effects of lactate and the general tumor acidosis has shown some unexpected benefits in both animal tumor models and in some cancer patients [198][199][200].…”

“…Likewise, the addition of certain basic compounds (such as bicarbonate, lysine, or Tris) in the diet to buffer against the effects of lactate and the general tumor acidosis has shown some unexpected benefits in both animal tumor models and in some cancer patients [198][199][200]. In many cases, the anticancer effects of these dietary modifications were amplified with the inclusion of more conventional chemotherapies or antimetabolite therapies [196,200] Metabolomics has also enabled the identification and mechanistic characterization of metabolites or dietary compounds that are anti-oncometabolites or cancer preventing agents. For instance, metabolome-wide association studies have shown that individuals with high plasma levels of vitamin C, carotenoids, and alpha-tocopherol were protected against gastric cancer [201], while those with high calcium and vitamin D levels were protected against colorectal cancer [201].…”

Scientific Evidences of Calorie Restriction and Intermittent Fasting for Neuroprotection in Traumatic Brain Injury Animal Models: A Review of the Literature

“…Since ancient times, worldwide religions have advocated for food restriction (FR) due to its physical and psychological benefits [ 1 , 2 , 3 ]. However, the health benefits owing to FR have only in recent years been supported by scientific evidence.…”

“…Calorie restriction (CR) is a commonly used FR strategy that restricts everyday energy intake without incurring malnutrition [ 4 ]. In experimental animal models, appropriate CR has been shown to have benefits including elongation of life span [ 5 ], promotion of weight loss [ 6 , 7 , 8 ], suppression of inflammation [ 9 , 10 , 11 ], cardiovascular disease risk reduction [ 12 , 13 , 14 ], and cancer prevention [ 2 , 15 ]. Notwithstanding these benefits, there are still concerns when applying CR, such as poor CR compliance [ 16 ].…”

“…One of these regimens is intermittent fasting (IF), and it has recently become a popular trend and lifestyle [ 17 ]. IF refers to cycles of fasting and intermittent feeding window over a given time schedule [ 2 , 16 , 18 ]. There are various time-scheduled IF methods, the following three are the most common approaches: periodic fasting (PE), time-restricted feeding (TRF) and alternate-day fasting (ADF) [ 16 ].…”