Unlocking Longevity: Can Fasting Make You Live Longer?
Fasting has been used therapeutically since at least the 5th century BCE when the Greek physician Hippocrates recommended abstinence from food or drink for patients exhibiting certain symptoms of illness. Throughout history, from ancient times to the present, humans have discovered amazing ways to lead life and extend their lifespan. Among various strategies and techniques, fasting emerges as a promising method with potential benefits for health and longevity.
Additionally, fasting reduces inflammation, protects cellular health, and decreases the risk of diabetes, cancer, and other cardiovascular diseases.
What is Fasting?
Fasting is the abstention from food consumption for a specific period. Its popularity has grown due to its effects on anti-ageing pathways and overall health. In modern times, with the advent of refrigeration, food preservation is easier. However, in ancient times, without refrigerators, people habitually practised fasting. This influenced cellular responses such as tissue growth, cell division, protein synthesis, and energy metabolism. Furthermore, autophagy, a process that maintains cellular balance by recycling old or damaged components, is influenced by the food we consume.
Fasting is often regarded as a diet, as many individuals adopt it for health or weight loss purposes. In strict fasting, no food or water is consumed, though electrolytes like sodium, potassium, and magnesium are acceptable. Less strict versions include no-calorie beverages such as black coffee, tea, or caffeine, effective appetite suppressants. In fat fasting, only fats are consumed, aiming to prolong the state of ketosis where fats are converted into energy. Juice fasting involves the consumption of only liquids or juices, excluding solid food.
The Science Behind Fasting
Fasting is an age-old concept in Indian households. Through fasting, individuals learn self-discipline, experience body detoxification, witness increased metabolism, and enjoy elevated growth hormones.
Metabolic Switching: A Shift from Glucose to Ketones
Under normal conditions with regular food intake, the body's primary energy source is glucose derived from carbohydrates. When food intake ceases, the body undergoes a metabolic switch, utilizing alternative energy sources, specifically fats. This process, known as ketosis, involves the breakdown of stored fatty acids in the liver, resulting in the production of ketone bodies such as acetoacetate, β-hydroxybutyrate, and acetone.
Autophagy: Cellular Cleanup and Renewal
Autophagy, derived from 'auto' meaning self and 'phagy' meaning eating, is a natural process allowing cells to recycle their own components for energy and regeneration. It serves as a housekeeping mechanism to digest and eliminate damaged organelles and proteins. Fasting reduces the activity of mTOR, responsible for inhibiting autophagy. Reduced food intake leads to decreased mTOR activity, allowing autophagy to continue or increase. Low energy levels stimulate AMPK activity, further enhancing autophagy.
Fasting Methods and Schedules
In the realm of health and wellness, fasting has emerged as a trending approach, drawing attention for its ability to promote weight loss, enhance metabolic health, and contribute to overall well-being. This practice involves cycling between two periods: the eating window and the fasting window. Common types of fasting include the 16/8 diet, 5:2 diet, eat-stop-repeat, alternate-day fasting, and the warrior diet.
Benefits of Fasting for Longevity
Fasting offers numerous health benefits, including weight loss, blood sugar control, and protection against certain illnesses. Restricting food intake to 5-7 hours a day enhances insulin sensitivity, resulting in reduced cell senescence and improved organ function. This practice helps organs resist stress. Typically, fasts are conducted over 24-72 hours. Here are the scientifically backed benefits of fasting.
Maintains Blood Sugar Levels
Fasting enhances insulin sensitivity, facilitating the body's efficient use of glucose as fuel. Reduced insulin production during fasting increases cell sensitivity, leading to more effective glucose utilization, consequently lowering blood sugar levels. Additionally, fasting reduces glucose production through gluconeogenesis, which holds potential benefits for individuals with diabetes. The breakdown of glycogen during fasting further contributes to the maintenance of blood sugar levels.
Promotes Better Health by Reducing Inflammation
Fasting reduces the production of pro-inflammatory cytokines, such as Interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α), known contributors to chronic inflammation linked to diseases like Alzheimer's, cancer, and heart disease. Simultaneously, fasting boosts the production of anti-inflammatory cytokines, including Interleukin-10 (IL-10), mitigating inflammation and suppressing the immune system. The reduction in oxidative stress during fasting further protects cells from damage and contributes to inflammation reduction (Sun et al., 2013).
Enhances Heart Health
Fasting positively impacts heart health by improving cholesterol levels. It lowers LDL (bad) cholesterol, reducing the risk of artery-clogging, while increasing HDL (good) cholesterol, which aids in LDL removal. This balance helps prevent heart disease by averting artery narrowing and decreasing the likelihood of strokes or heart attacks. Fasting also has the potential to lower blood pressure by reducing stress hormone levels, relaxing blood vessels, and subsequently lowering blood pressure.
Boosts Brain Function
Fasting increases the production of brain-derived neurotrophic factor protein (BDNF), promoting the development and protection of brain cells. Numerous studies demonstrate fasting's positive impact on cognitive function, with improvements in memory and attention observed in healthy adults after a five-day fast. Individuals with neurological conditions like Parkinson's and Alzheimer's disease may also benefit from fasting, showing improvements in cognitive function and potential disease progression slowing. (Iu & Chan, 2022)
Promotes Weight Loss
Fasting induces weight loss through multiple mechanisms. It reduces calorie intake compared to regular meals, creating a calorie deficit essential for weight loss. Additionally, fasting triggers increased fat burning as the body depletes glycogen stores, its primary energy source. The modulation of hunger hormones, such as lowering ghrelin (the "hunger hormone") and increasing cholecystokinin (a satiety hormone), contributes to reduced appetite during fasting. (Stockman et al., 2018)
What to Eat When Fasting
Hydration is Key:
Staying hydrated is crucial during fasting to prevent headaches, weakness, and fatigue. Aim for at least 3 litres of water daily to maintain bodily functions, regulate temperature, and avoid dehydration.
During fasting, focus on nutrient-dense, whole foods:
- Fruits like watermelon, banana, apples, strawberries, and oranges provide hydration and prevent binge eating.
- Include fresh vegetables like pumpkin, sweet potato, and cucumber to prevent insulin spikes.
- Lean proteins such as egg whites, cottage cheese, white meat, and tofu aid muscle repair and maintenance.
- Whole grains like buckwheat, amaranth, and water chestnut provide sustained energy.
- Healthy Fats: Incorporate healthy fats like coconut oil, ghee, and MCT oil for ketosis, autophagy, and improved cognitive function. Coconut oil, rich in MCTs, contains lauric acid with antimicrobial properties. Ghee is an energy source with essential fatty acids. Avocados offer healthy fats, fibres, and potassium.
Enjoy zero-calorie options to stay energized:
- Unsweetened black coffee or tea provides a caffeine boost.
- Diluted apple cider vinegar curbs hunger and promotes fullness.
- Non-vegetarians can benefit from low-calorie bone broth, which supports joint health with electrolytes, minerals, and collagen.
Maintaining a balance of these elements ensures a nourishing and effective fasting experience.
Unveiling the Scientific Evidence Behind Fasting
Fasting serves as a method to control LDL levels and promote overall health. In a study with 740 healthy participants, fasting not only reduced LDL levels but also led to weight loss, contributing to a lower risk of cardiovascular diseases. (Samudera et al., 2020).
A separate study conducted by University of Alabama researchers focused on a small group of obese men with prediabetes. They engaged in early time-restricted feeding, spacing all meals over a 12-hour period (7 am to 7 pm). After five weeks, the eight-hour fasting group exhibited significantly lower insulin levels, improved insulin sensitivity, and lower blood pressure. Notably, both groups maintained their weight without gain or loss. (Sutton et al., 2018).
Research on dietary restriction reveals various health benefits, including enhanced insulin sensitivity, stress resistance, reduced morbidity, and increased lifespan. In a study involving C57BL/6 mice, intermittent fasting, particularly alternate-day fasting, resulted in weight loss. Despite maintaining body weight, mice undergoing intermittent fasting exhibited lower glucose and insulin levels, improved glucose regulation, and enhanced metabolic health. Fasting also demonstrated neuroprotective effects during induced stress, highlighting its positive impact on brain health. (Anson et al., 2003).
Research strongly supports the notion that fasting is an effective long-term strategy. It initiates a metabolic switch, promoting autophagy and ketosis crucial for cell renewal. Various fasting techniques, such as the 16/8 diet and alternate-day fasting, offer flexibility and numerous health benefits. Fasting contributes to lowering blood sugar, reducing inflammation, strengthening the heart, enhancing cognitive function, and facilitating weight loss.
To support the body with necessary nutrients and hydration during fasting, individuals consume nutrient-dense foods and zero-calorie beverages. This modern application of ancient wisdom aligns seamlessly with contemporary well-being goals, offering a holistic approach to lifespan and health.
1) Does fasting increase life expectancy?
Yes, there is some evidence that fasting can increase life expectancy. For example, a study of mice found that those who fasted lived longer than those who did not. Additionally, fasting has been shown to reduce inflammation, protect cellular health, and decrease the risk of diabetes, cancer, and other cardiovascular diseases. These factors may all contribute to increased longevity. However, more research is needed to confirm whether fasting can actually extend the human lifespan.
2) Is fasting anti-ageing?
Yes, it is believed that fasting prevents ageing. Treating important aspects linked to ageing increases metabolic health decreases inflammation, and encourages cellular renewal, all of which contribute to lifespan.
3) How long is the fasting diet for longevity?
The length of fasting required for lifespan differs between techniques. Methods such as the 16/8 diet call for 16-hour periods of fasting every day, whereas alternate-day fasting calls for fasting every other day. Because it's flexible, people can set a fasting schedule that works for them, which makes it an individualised and sustainable way to promote longevity.
4) How often should I fast for longevity?
Intermittent fasting regimens such as the 16/8 or 5:2 diets are well-liked because they promote longevity. It may be sufficient to fast two or three times a week or to occasionally observe 24-hour fasts. Customise according to your health and lifestyle, and seek advice from a medical practitioner for recommendations on a long-term fasting schedule.
5) Is it healthy to fast long term?
Prolonged fasting can lead to hazards and dietary deficits. It is essential to consult a healthcare provider. While short-term intermittent fasting has been linked to health advantages, prolonged fasting must be carefully considered and closely monitored to ensure overall well-being.
Sukma Samudera, W., Victoria Fernandez, G., Fitriyah, R., Arifin, H., Maulina Wulandari, S., & Aji Permana, R. (2019). The Benefits of Fasting to Improve Health Conditions and to Prevent Cardiovascular Disease.
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.
Anson, R. M., Guo, Z., de Cabo, R., Iyun, T., Rios, M., Hagepanos, A., ... & Mattson, M. P. (2003). Intermittent fasting dissociates the beneficial effects of dietary restriction on glucose metabolism and neuronal resistance to injury from calorie intake. Proceedings of the National Academy of Sciences, 100(10), 6216-6220.
Hollstein, T., Basolo, A., Unlu, Y., Ando, T., Walter, M., Krakoff, J., & Piaggi, P. (2022). Effects of short-term fasting on ghrelin/GH/IGF-1 axis in healthy humans: the role of ghrelin in the thrifty phenotype. The Journal of Clinical Endocrinology & Metabolism, 107(9), e3769-e3780.
Stockman, M. C., Thomas, D., Burke, J., & Apovian, C. M. (2018). Intermittent fasting: is the wait worth the weight?. Current obesity reports, 7, 172-185.
Sun, K., Deng, W., Zhang, S., Cai, N., Jiao, S., Song, J., & Wei, L. (2013). Paradoxical roles of autophagy in different stages of tumorigenesis: protector for normal or cancer cells. Cell & bioscience, 3(1), 1-8.
Iu, E. C. Y., & Chan, C. B. (2022). Is Brain-Derived Neurotrophic Factor a Metabolic Hormone in Peripheral Tissues?. Biology, 11(7), 1063.