Study: “Intermittent and periodic fasting, longevity and disease”
Publisher: Nature
Published date: March 2022
PubMed link to study: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8932957/
A scientific review focused on the research on intermittent and periodic fasting and its benefits has been published in Nature Aging. This review highlights the potential benefits of intermittent and periodic fasting for promoting longer and healthier lives.
These fasting methods involve alternating periods of eating and fasting, and research suggests that this method may promote longer, healthier lives by supporting cellular repair, improving metabolic health, and reducing the risk of age-related diseases. While some of these findings come from human studies, much of the research is still based on animal models.
Feel welcome to share your own thoughts on this research in the comment section below as well. I will be happy to discuss and learn more about how you see its potential in this field.
What is Intermittent and Periodic Fasting
Intermittent Fasting (IF) involves alternating between periods of eating and fasting. Common approaches include:
- 16:8 Method: Fasting for 16 hours and eating during an 8-hour window each day.
- 5:2 Diet: Consuming a normal diet for five days a week and significantly reducing caloric intake on the other two days.
- Alternate-Day Fasting (ADF): Alternating between days of normal eating and days with either no food or very limited caloric intake.
Periodic Fasting (PF) typically involves longer fasting periods, lasting from 2 to 7 days, and is repeated less frequently, such as once a month or less. A specific type of periodic fasting, the Fasting-Mimicking Diet (FMD), uses a plant-based, low-protein, low-sugar, and high-fat diet designed to simulate the effects of fasting while providing some nutrition.
How Fasting Influences Longevity: Evidence from Animal Studies
Research in animals, particularly rodents, has provided much of the foundational evidence for the benefits of intermittent and periodic fasting:
- Cellular Maintenance and Repair: In animal studies, fasting has been shown to activate autophagy, which is a process where cells remove and recycle damaged components. This helps prevent the accumulation of cellular damage, which is believed to contribute to aging. These findings are particularly well-documented in mice, where intermittent fasting has been shown to enhance autophagy and other cellular repair processes.
- Reduction in Insulin and IGF-1 Levels: Animal studies indicate that both intermittent and periodic fasting lower levels of insulin and insulin-like growth factor 1 (IGF-1). These hormones, while important for growth, are also associated with aging and cancer when present at high levels. In rodents, reduced IGF-1 levels from fasting have been linked to extended lifespan and a lower risk of age-related diseases.
- Enhanced Regeneration: Studies in mice have demonstrated that fasting, particularly when combined with refeeding, can activate stem cells and promote tissue regeneration. For example, periodic fasting has been shown to stimulate the regeneration of immune cells in mice, potentially rejuvenating the immune system and improving its ability to fight disease.
- Improved Metabolic Health: In animal models, fasting has been shown to improve insulin sensitivity, lower blood pressure, reduce inflammation, and improve markers of metabolic health. These changes have been observed to contribute to a reduced risk of metabolic diseases, such as diabetes and cardiovascular conditions in rodents.
Potential Benefits of Fasting for Age-Related Diseases: Insights from Human Studies
While much of the research on fasting has been conducted in animal models, several human studies provide early evidence of potential health benefits:
- Cancer: Some small human studies suggest that fasting, including the fasting-mimicking diet (FMD), may help protect normal cells and make cancer cells more susceptible to chemotherapy. However, most of the evidence for fasting’s anti-cancer effects comes from animal studies. Human research is still in its early stages and primarily focuses on the safety and feasibility of fasting in conjunction with traditional cancer treatments.
- Neurodegenerative Diseases: While animal studies show that fasting can protect brain health and improve cognitive function, human studies are more limited. Preliminary research indicates that intermittent fasting may have cognitive benefits, but more robust clinical trials are needed to confirm its effects in preventing or slowing neurodegenerative diseases like Alzheimer’s or Parkinson’s.
- Cardiovascular and Metabolic Diseases: Human studies provide more substantial evidence for the benefits of intermittent fasting on cardiovascular and metabolic health. For example, human trials have shown that intermittent fasting can reduce blood pressure, improve cholesterol profiles, and enhance insulin sensitivity in individuals with obesity or metabolic syndrome. However, most human studies are relatively short-term, and longer studies are needed to determine the sustained impact of these interventions.
- Autoimmune Diseases: Human studies have explored fasting’s impact on autoimmune conditions, such as multiple sclerosis (MS). A clinical trial showed that fasting-mimicking diets could reduce symptoms and improve quality of life in people with MS. However, these findings need to be confirmed in larger, more comprehensive studies.
Balancing Benefits and Risks
While both animal and human studies highlight the potential benefits of fasting, it is crucial to approach these dietary interventions carefully. Most of the compelling evidence comes from animal studies, which may not directly translate to humans due to physiological differences. Furthermore, human studies have limitations, such as small sample sizes and short durations, which make it challenging to draw definitive conclusions about the long-term effects of fasting.
Potential side effects, including nutrient deficiencies and health risks associated with prolonged fasting periods, need careful consideration. As such, if you are interested in trying any of the mentioned fasting methods it is important to do so in a careful manner and preferably with the guidance of healthcare professionals, particularly if you have existing health conditions or are taking medications.
The authors highlights that the effects of fasting can vary depending on the age and health status of the individual. For instance, while fasting may be beneficial for younger and middle-aged individuals, it may have mixed or even detrimental effects in older adults, especially if they are frail or have existing health conditions. This point underscores the need for a personalized approach to fasting.
The authors also point out the necessity for more extensive, long-term human studies to better understand the effects of different fasting regimens on aging and disease prevention. The current evidence is promising but incomplete, and there is a need for more targeted research to determine the most effective fasting protocols for different populations.
In Summary
While fasting shows promise as a potential way to improve overall health and longevity, much of the current understanding is based on animal research. Human studies are beginning to provide supporting evidence, but more research is needed to confirm these findings, establish optimal fasting regimens, and understand the long-term effects.
Until then, fasting should be considered a potentially beneficial strategy, but one that requires careful application and further investigation. By distinguishing between animal and human research, individuals can better understand the current evidence and make informed decisions about incorporating fasting into their lives for better health and longevity.
