Traditional religious practices in Christianity, Buddhism, Islam have all included fasting (Karras et al., 2016). In yoga, fasting is a pillar of the philosophical principle of sauca, or purity. While abstaining from worldly delights (sex, food, alcohol) is certainly a test of mental fortitude, research has shown that caloric reduction through intermittent and periodic fasting can promote longevity and cellular health.
Fasting and Disease Prevention
Researchers have known for years that caloric reduction in mice promotes longevity. In fact, in experimental models, fasting has improved disease outcomes for a wide range of age-related challenges, including “diabetes, cardiovascular disease, cancers and neurological disorders such as Alzheimer’s disease, Parkinson’s disease and stroke” (Harvie et al., 2016). Dr. Valter Longo, the Director of the Longevity Institute at the University of Southern California, has done substantial (and remarkable) research into the correlation between caloric control and disease prevention and longevity and has shown a correlation between fasting mimicking diets and cancer prevention and treatment.
Why Does Fasting Work?
Basically, humans evolved to cope with food scarcity. When we fast, the stress on our cells activates a cellular response that improves “mitochondrial health, DNA repair and autophagy…[and] promotes stem cell-based regeneration as well as long-lasting metabolic effects” (Harvie et al., 2016). Autophagy is where our body “eats” itself (starting with stuff that is damaged, diseased and non-essential). When we fast, the body starts to get rid of bad stuff, then when we eat again, our body uses stem cells to rebuild our body afresh.
My 50-year old brother-in-law (a very curious cat about longevity practices) has been exploring fasting techniques in his own life for several years, and is not back to his “fighting weight” from college. My sister, who joined on with him, is now fitting into clothes that have been in the back of her closet for years. However, while fasting can help you lose weight, the less visible benefits (promoting the immune system, cellular regeneration, reduction of inflammation) are far more profound.
Types of Common Fast-Mimicking Diets
- 5:2 Diet: participants restrict calories by 60% for two days of the week, then eat regularly for five.
- Time Restricted Feeding: participants restrict food intake to a 6-hour window of time each day in order to prolong the natural fasting period of the body.
- Intermittent Fasting: fasting for 16 hours to 2 days
- Periodic Fasting: fasting for 2-21 days
I have played with Time Restricted Feeding and Intermittent Fasting. I find that Time Restricted Feeding (restricting food intake to a 6-hour window) is fairly accessible once you get used to pushing breakfast til past 3 pm. And culturally, it’s a bit easier to not eat breakfast or lunch than to forgo all dinner invitations.
As my anatomy teacher Gil Hedley says, “we are the species that plays with itself.” Just as yoga and meditation practices can deeply impacts your nervous system, your dietary choices will impact some of your deepest cellular processes. If you are interested in exploring these diets, arm yourself with some research. Not only is it fascinating, it will motivate you to last through the initial hunger pangs. Fasting strategies are not appropriate for everyone: pregnant women and children should eat regularly.
Happy and healthy exploring.
Ted Talk with Dr. Valter Longo (20 minutes)
Ted Talk with Mark Mattson, the current Chief of the Laboratory of Neurosciences at the National Institute on Aging and professor of Neuroscience at The Johns Hopkins University (17 minutes).
Video Interview with Dr. Valter Longo, Director of the Longevity Institute at the University of Southern California, describing his work in research with fasting (1 hour)
D, A. P. R., D, S. K. M. D. P., & D, C. P. M. D. P. (2017). Unraveling the metabolic health benefits of fasting related to religious beliefs: A narrative review. Nutrition, 35, 14–20. http://doi.org/10.1016/j.nut.2016.10.005
Mattson, M. P., Longo, V. D., & Harvie, M. (2017). Impact of intermittent fasting on health and disease processes.
Ageing Research Reviews, 39, 46–58. http://doi.org/10.1016/j.arr.2016.10.005
PhD, R. E. P., PhD, G. A. L., PhD, D. D. S., PhD, A. Z. L., Marinac, C., PhD, L. C. G., et al. (2015). Intermittent Fasting and
Human Metabolic Health. Journal of the Academy of Nutrition and Dietetics, 115(8), 1203–1212. http://doi.org/10.1016/j.jand.2015.02.018
Schübel, R., Graf, M. E., Nattenmüller, J., Nabers, D., Sookthai, D., Gruner, L. F., et al. (2016). The effects of intermittent calorie restriction on metabolic health: Rationale and study design of the HELENA Trial. Contemporary Clinical Trials, 51(C), 28–33. http://doi.org/10.1016/j.cct.2016.09.004
Seimon, R. V., Roekenes, J. A., Zibellini, J., Zhu, B., Gibson, A. A., Hills, A. P., et al. (2015). Do intermittent diets provide physiological benefits over continuous diets for weight loss? A systematic review of clinical trials. Molecular and
Cellular Endocrinology, 418(Part 2), 153–172. http://doi.org/10.1016/j.mce.2015.09.014