Types of fasting[edit | edit source]
Water only fasting[edit | edit source]
As the name implies, this is a type of fasting where only water may be consumed – no other food or beverage is permitted.
Liquid fasting[edit | edit source]
Some fasts include abstaining from solid foods but consuming calorie-containing liquids, such as vegetables juices or broth.
Intermittent fasting[edit | edit source]
In this form of fasting, a person alternates between periods of fasting and non-fasting, with a defined schedule. Intermittent fasting is of interest to researchers for its potential effects on insulin sensitivity and other aspects of health. Popular types of intermittent fasting include: 16:8, 16-hr fast with a 8-hr eating window, 18:6, 18-hr fast with a 6-hr eating window, 20:4, 20-hr fast with a 4-hr eating window. The alternate day fast is a 36 hour fast followed by a 12-hr eating window.
Caloric restriction[edit | edit source]
A calorie restricted (CR) diet reduces calorie intake without malnutrition. It is chronic and does not include a refeeding phase. Most clinical trials of CR aim for 25-30% total calorie reduction. The 5:2 diet is a calorically restricted diet in which 2 days per week one consumes 500-600 calories, and eats normally the remaining 5 week days.
Physiological effects[edit | edit source]
A fast with duration sufficient to deplete the body's glycogen stores, at least 18 hours, increases the blood ketone β-hydroxybutyrate allowing for nutritional ketosis.
Fasting increases autophagy in mice.
The US National Institute on Aging and the National Institute of Diabetes and Digestive and Kidney Diseases conducted the CALERIE (Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy) study using a 2-year CR diet (25% reduction) in non-obese adults (n = 143) compared to an ad libitum group (n =75). The CR group reported improvements in mood and improved sleep quality without adverse effects or immune compromise. There was also improvement in cardiovascular risk factors including C-reactive protein.
Health effects[edit | edit source]
There is no evidence on the benefits or harms of fasting for ME and CFS patients. However, there is a growing body of evidence suggesting possible health benefits of water-only fasting to the microbiome, mitochondria and the immune system, and as a cancer adjuvant.
Immune system[edit | edit source]
Caloric restriction significantly reduced the amount of circulating lipopolysaccharide-binding protein. In vitro, short-term (19 hour) fasting reduced monocyte metabolic and inflammatory activity and drastically reduced the number of circulating monocytes. This effect is thought to be due to redistribution of these cells to the bone marrow. Caloric restriction and intermittent fasting strongly reduced the accumulation of pathogenic monocytes in the central nervous system, reduced monocyte pro-inflammatory activity, and improved disease outcome in a mouse model of multiple sclerosis and in a preclinical model in multiple sclerosis patients.
Chronic fatigue syndrome[edit | edit source]
See also[edit | edit source]
Learn more[edit | edit source]
References[edit | edit source]
- Kraus, William E.; Bhapkar, Manjushri; Huffman, Kim M.; Pieper, Carl F.; Krupa Das, Sai; Redman, Leanne M.; Villareal, Dennis T.; Rochon, James; Roberts, Susan B. (September 2019). "2 years of calorie restriction and cardiometabolic risk (CALERIE): exploratory outcomes of a multicentre, phase 2, randomised controlled trial". The Lancet. Diabetes & Endocrinology. 7 (9): 673–683. doi:10.1016/S2213-8587(19)30151-2. ISSN 2213-8595. PMC 6707879. PMID 31303390.
- Remely, Marlene; Hippe, Berit; Geretschlaeger, Isabella; Stegmayer, Sonja; Hoefinger, Ingrid; Haslberger, Alexander (May 2015), "Increased gut microbiota diversity and abundance of Faecalibacterium prausnitzii and Akkermansia after fasting: a pilot study", Wiener Klinische Wochenschrift, 127 (9–10): 394–398, doi:10.1007/s00508-015-0755-1, ISSN 1613-7671, PMID 25763563
- Cerqueira, Fernanda M.; Laurindo, Francisco R. M.; Kowaltowski, Alicia J. (March 31, 2011), "Mild Mitochondrial Uncoupling and Calorie Restriction Increase Fasting eNOS, Akt and Mitochondrial Biogenesis", PLOS ONE, 6 (3): 18433, doi:10.1371/journal.pone.0018433, ISSN 1932-6203, retrieved November 9, 2016
- Cheng, Chia-Wei; Adams, Gregor B.; Perin, Laura; Wei, Min; Zhou, Xiaoying; Lam, Ben S.; Da Sacco, Stefano; Mirisola, Mario; Quinn, David I.; Dorff, Tanya B.; Kopchick, John J.; Longo, Valter D. (June 5, 2014), "Prolonged Fasting Reduces IGF-1/PKA to Promote Hematopoietic-Stem-Cell-Based Regeneration and Reverse Immunosuppression", Cell Stem Cell, 14 (6): 810–823, doi:10.1016/j.stem.2014.04.014, ISSN 1934-5909, retrieved November 9, 2016
- Lee, Changhan; Raffaghello, Lizzia; Brandhorst, Sebastian; Safdie, Fernando M.; Bianchi, Giovanna; Martin-Montalvo, Alejandro; Pistoia, Vito; Wei, Min; Hwang, Saewon; Merlino, Annalisa; Emionite, Laura; Cabo, Rafael de; Longo, Valter D. (March 7, 2012), "Fasting Cycles Retard Growth of Tumors and Sensitize a Range of Cancer Cell Types to Chemotherapy", Science Translational Medicine, 4 (124): 124–27-124ra27, doi:10.1126/scitranslmed.3003293, ISSN 1946-6234, PMID 22323820, retrieved November 9, 2016
- Lee, C.; Longo, V. D. (July 28, 2011), "Fasting vs dietary restriction in cellular protection and cancer treatment: from model organisms to patients", Oncogene, 30 (30): 3305–3316, doi:10.1038/onc.2011.91, ISSN 0950-9232, retrieved November 9, 2016
- Safdie, Fernando M.; Dorff, Tanya; Quinn, David; Fontana, Luigi; Wei, Min; Lee, Changhan; Cohen, Pinchas; Longo, Valter D. (December 31, 2009), "Fasting and cancer treatment in humans: A case series report", Aging (Albany NY), 1 (12): 988–1007, ISSN 1945-4589, PMID 20157582, retrieved November 9, 2016
- Zhang, Chenhong; Li, Shoufeng; Yang, Liu; Huang, Ping; Li, Wenjun; Wang, Shengyue; Zhao, Guoping; Zhang, Menghui; Pang, Xiaoyan; Yan, Zhen; Liu, Yong; Zhao, Liping (July 16, 2013), "Structural modulation of gut microbiota in life-long calorie-restricted mice", Nature Communications, 4: 2163, doi:10.1038/ncomms3163, ISSN 2041-1723, retrieved November 9, 2016
- Cignarella, Francesca; Cantoni, Claudia; Ghezzi, Laura; Salter, Amber; Dorsett, Yair; Chen, Lei; Phillips, Daniel; Weinstock, George M.; Fontana, Luigi (June 5, 2018). "Intermittent Fasting Confers Protection in CNS Autoimmunity by Altering the Gut Microbiota". Cell Metabolism. 27 (6): 1222–1235.e6. doi:10.1016/j.cmet.2018.05.006. ISSN 1932-7420. PMC 6460288. PMID 29874567.
- Craig, Courtney (November 2015), "Mitoprotective dietary approaches for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Caloric restriction, fasting, and ketogenic diets", Medical Hypotheses, 85 (5): 690-693, doi:10.1016/j.mehy.2015.08.013, PMID 26315446
β β / Β. Greek letter beta (a symbol used in science), equivalent to "b".
central nervous system (CNS) - One of the two parts of the human nervous system, the other part being the peripheral nervous system. The central nervous system consists of the brain and spinal cord, while the peripheral nervous system consists of nerves that travel from the central nervous system into the various organs and tissues of the body.
mouse model The use of special strains of mice to study a human disease or condition, and how to prevent and treat it
myalgic encephalomyelitis (M.E.) - A disease often marked by neurological symptoms, but fatigue is sometimes a symptom as well. Some diagnostic criteria distinguish it from chronic fatigue syndrome, while other diagnostic criteria consider it to be a synonym for chronic fatigue syndrome. A defining characteristic of ME is post-exertional malaise (PEM), or post-exertional neuroimmune exhaustion (PENE), which is a notable exacerbation of symptoms brought on by small exertions. PEM can last for days or weeks. Symptoms can include cognitive impairments, muscle pain (myalgia), trouble remaining upright (orthostatic intolerance), sleep abnormalities, and gastro-intestinal impairments, among others. An estimated 25% of those suffering from ME are housebound or bedbound. The World Health Organization (WHO) classifies ME as a neurological disease.