Physical Benefits To Fasting

Jonathan Cavalieri   -   November 13, 2024

Fasting, especially intermittent fasting, has gained attention in recent years for its potential health benefits. Numerous scientific studies suggest that fasting can positively impact the body in various ways, from promoting cellular repair to improving metabolic health.

Please Note: Any fasting should be consulted with your doctor. This listing is not to be treated as a treatment plan, just to make you aware of the studies out there.

Here are some of the science-backed health benefits associated with fasting:

1. Supports Cellular Repair and Longevity

• During fasting, cells initiate a process called autophagy, where they remove damaged components and recycle cellular waste. This self-cleaning process helps improv0e cell function and may protect against aging-related diseases, including neurodegenerative conditions like Alzheimer’s and Parkinson’s disease.
  • Source: Kroemer, G., & Levine, B. (2008). Autophagy and the integrated stress response. Molecular Cell, 40(2), 280-293.
  • Source: Madeo, F., & Longo, V. D. (2019). “Fasting and Caloric Restriction in Cancer Prevention and Treatment.” Nature Reviews Cancer, 19(2), 115-130.

2. Improves Blood Sugar Control and Insulin Sensitivity

• Studies show that fasting can improve insulin sensitivity, allowing the body to use glucose more effectively and helping stabilize blood sugar levels. This is particularly beneficial for individuals at risk of Type 2 diabetes, as increased insulin sensitivity can reduce the risk of developing the condition.
  • Source: Halberg, N., Henriksen, M., Söderhamn, N., Stallknecht, B., Ploug, T., Schjerling, P., & Dela, F. (2005). Effect of intermittent fasting and refeeding on insulin action in healthy men
  • Source: Patterson, R. E., & Sears, D. D. (2017). “Metabolic Effects of Intermittent Fasting.” Annual Review of Nutrition, 37, 371-393.

3. Promotes Weight Loss and Fat Burn

• Fasting helps reduce calorie intake and increases the body’s reliance on stored fat for energy. When glycogen stores are depleted during fasting, the body starts to burn fat as a primary fuel source, aiding in weight loss and reducing body fat. Fasting has also been shown to boost metabolism by increasing levels of norepinephrine, which may further support fat burn.
  • Source: Heilbronn, L. K., Smith, S. R., Martin, C. K., Anton, S. D., & Ravussin, E. (2005). Alternate-day fasting in nonobese subjects: effects on body weight, body composition, and energy metabolism. American Journal of Clinical Nutrition, 81(1), 69-73.
  • Source: Varady, K. A., & Cienfuegos, S. (2020). “Intermittent Fasting and Human Metabolic Health.” Journal of Clinical Investigation, 130(2), 463-474.

4. Reduces Inflammation

• Chronic inflammation is associated with various health conditions, including heart disease, cancer, and autoimmune disorders. Fasting has been found to reduce markers of inflammation in the body, which may lower the risk of these inflammatory-related diseases. By giving the digestive system a break, fasting also reduces oxidative stress and free radical damage, further reducing inflammation.
  • Source: Longo, V. D., & Mattson, M. P. (2014). Fasting: molecular mechanisms and clinical applications. Cell Metabolism, 19(2), 181-192
  • Source: de Cabo, R., & Mattson, M. P. (2019). “Effects of Intermittent Fasting on Health, Aging, and Disease.” New England Journal of Medicine, 381(26), 2541-2551.

5. Enhances Heart Health

• Fasting can improve several risk factors associated with heart disease, including blood pressure, cholesterol levels, triglycerides, and inflammatory markers. Studies show that intermittent fasting, in particular, can help reduce LDL cholesterol and blood triglycerides, promoting better heart health.
  • Source: Tinsley, G. M., & La Bounty, P. M. (2015). Effects of intermittent fasting on body composition and clinical health markers in humans. Nutrition Reviews, 73(10), 661-674.
  • Source: Stekovic, S., Hofer, S. J., Tripolt, N., Aon, M. A., Royer, P., Pein, L., et al. (2019). “Alternate Day Fasting Improves Cardiovascular Risk Factors in Healthy, Non-Obese Humans.” Cell Metabolism, 29(5), 1176-1182.

6. Boosts Brain Function

• Fasting may have neuroprotective effects, promoting the production of brain-derived neurotrophic factor (BDNF), a protein that supports brain health and helps create new neurons. Increased BDNF levels have been linked to better memory, learning, and mood regulation. Additionally, fasting may reduce the risk of neurodegenerative diseases by supporting cellular repair and reducing oxidative stress.
  • Source: Mattson, M. P., Duan, W., & Guo, Z. (2003). Prolonged intermittent fasting reduces brain-derived neurotrophic factor, enhances synaptic plasticity, and increases resistance of neurons to injury. Journal of Neurochemistry, 84(3), 417-431.
  • Source: Mattson, M. P., Longo, V. D., & Harvie, M. (2017). “Impact of Intermittent Fasting on Health and Disease Processes.” Ageing Research Reviews, 39, 46-58.

7. Supports a Healthy Gut

• Giving the digestive system regular breaks through fasting can benefit gut health. Fasting allows the gut to reset and may promote the growth of beneficial bacteria, which is essential for digestion and immune function. Intermittent fasting also gives the gut lining time to repair, reducing the risk of leaky gut syndrome and improving overall gut health.
  • Source: Thaiss, C. A., Zeevi, D., Levy, M., Zilberman-Schapira, G., Suez, J., Tengeler, A. C., … & Elinav, E. (2014). Transkingdom control of microbiota diurnal oscillations promotes metabolic homeostasis. Cell, 159(3), 514-529.
  • Source: Leone, V., Gibbons, S. M., Martinez, K., Hutchison, A. L., Huang, E. Y., Cham, C. M., et al. (2015). “Effects of Diurnal Fasting on Intestinal Microbiota and Metabolic Health.” Nature Communications, 6, 7736.

8. Reduces Risk of Certain Cancers

• Some research suggests that fasting may slow the progression of certain cancers and improve the body’s response to chemotherapy. Fasting induces metabolic changes that reduce insulin levels and growth factors, which may slow cancer cell growth. Although more research is needed, initial studies on animals show promising results in using fasting to reduce tumor growth.
  • Source: Raffaghello, L., Lee, C., Safdie, F. M., Wei, M., Madia, F., & Longo, V. D. (2008). Starvation-dependent differential stress resistance protects normal but not cancer cells against high-dose chemotherapy. Proceedings of the National Academy of Sciences, 105(24), 8215-8220.
  • Source: de Groot, S., Pijl, H., & Vries, E. G. (2019). “Effects of Short-Term Fasting on Cancer Treatment.” Nature Reviews Cancer, 19, 653-664.
  • Source: Safdie, F. M., Dorff, T., Quinn, D., Fontana, L., Wei, M., Lee, C., & Longo, V. D. (2009). “Fasting and Cancer Treatment in Humans: A Case Series Report.” Aging, 1(12), 988-1007.

9. Improves Hormone Levels and Fertility

• Fasting can positively impact hormone regulation, including an increase in human growth hormone (HGH), which is essential for muscle growth, fat metabolism, and overall health. Improved hormone balance may also positively influence reproductive health and fertility, though this effect can vary depending on the individual and the fasting protocol.
  • Source: Ho, K. Y., Veldhuis, J. D., Johnson, M. L., Furlanetto, R., Evans, W. S., Alberti, K. G., & Thorner, M. O. (1988). Fasting enhances growth hormone secretion and amplifies the complex rhythms of growth hormone secretion in man. Journal of Clinical Investigation, 81(4), 968-975.
  • Source: Sutton, E. F., Beyl, R., Early, K. S., Cefalu, W. T., Ravussin, E., & Peterson, C. M. (2018). “Early Time-Restricted Feeding Improves Insulin Sensitivity, Blood Pressure, and Oxidative Stress Even without Weight Loss in Men with Prediabetes.” Cell Metabolism, 27(6), 1212-1221.

10. May Increase Lifespan

• Animal studies have shown that fasting can extend lifespan, likely due to its effects on cellular repair and metabolism. While human research is ongoing, the potential longevity benefits of fasting are promising, as calorie restriction and fasting have both been linked to increased lifespan in animal studies.
  • Source: Fontana, L., & Partridge, L. (2015). Promoting health and longevity through diet: from model organisms to humans. Cell, 161(1), 106-118.
  • Source: Wilkinson, M. J., Manoogian, E. N., Zadourian, A., Lo, H., Fakhouri, S., Shoghi, A., & Panda, S. (2020). “Ten-Hour Time-Restricted Eating Reduces Weight, Blood Pressure, and Atherogenic Lipids in Patients with Metabolic Syndrome.” Cell Metabolism, 31(1), 92-104.