From: hubermanlab
Fasting has been a topic of considerable interest in the context of longevity and health. In a conversation between Andrew Huberman and Dr. David Sinclair on the Huberman Lab Podcast, the scientific basis for fasting as a tool for enhancing lifespan and delaying the onset of age-related diseases was thoroughly discussed.
The Role of Fasting in Longevity
Dr. David Sinclair, a professor of genetics at Harvard Medical School, has dedicated much of his research to understanding the mechanisms of aging and how they can be influenced by lifestyle factors such as fasting. He highlighted that fasting can activate specific longevity genes and pathways that are crucial for maintaining cellular health and delaying the aging process. The role of sirtuins in aging is significant, as these proteins are known for their impact on longevity. Learn more about the role of sirtuins and epigenome in aging.
Mechanisms Behind Fasting’s Benefits
Dr. Sinclair explained that fasting contributes to longevity by engaging the body’s natural defenses against aging through mechanisms such as:
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Sirtuins Activation: Sirtuins are a group of proteins that play a critical role in cellular health. During fasting, sirtuins are activated due to low insulin and glucose levels, promoting cellular repair and survival mechanisms that counteract aging ([00:26:01]).
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mTOR Pathway Downregulation: The mTOR pathway, which is sensitive to amino acid levels, particularly leucine, lysine, and valine, is downregulated during fasting. This leads to decreased cellular growth and increased cellular repair, both of which are beneficial for longevity ([00:37:01]). Explore more about the impact of diet and exercise on hormone health.
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Autophagy Enhancement: Longer fasting periods (more than 24 hours) trigger autophagy, a process that removes damaged cellular components. Specifically, after two to three days of fasting, a deep-cleansing process known as chaperone-mediated autophagy is engaged, which is thought to significantly contribute to extending lifespan ([00:33:57]). For more insights on the benefits of fasting, see intermittent fasting and cognition.
Practical Fasting Protocols
Intermittent Fasting: Dr. Sinclair recommends intermittent fasting, at least skipping one meal a day, typically breakfast, to extend the fasting period overnight. This not only assists in managing blood glucose levels but also maintains low insulin levels, which is beneficial for longevity ([00:24:03]). Delve into more on the roles of fasting and eating schedules on metabolism.
Extended Fasting: On occasion, Dr. Sinclair practices extended fasting, such as going without food for 48 to 72 hours, to induce deeper autophagy and cellular repair processes ([00:33:55]).
Hunger and Longevity
Interestingly, the subjective experience of hunger itself might be beneficial for longevity. Dr. Sinclair mentioned that the sensation of hunger could signal the body to engage its defensive modes, thus promoting activities that support longevity, though the experience of hunger tends to diminish once one is adapted to fasting ([00:27:00]). This can relate to the biological mechanisms of hunger and satiety.
Summary
The discussion between Andrew Huberman and Dr. David Sinclair provides compelling evidence that fasting can be a potent tool in promoting longevity. By reducing insulin and glucose levels, activating longevity genes like sirtuins, and enhancing autophagy, fasting helps to maintain cellular health and potentially extends lifespan. Adopting fasting protocols, such as intermittent fasting or occasional extended fasting, aligns with modern scientific understanding of pathways that avoid aging and promote health. Investigate further the health benefits of time-restricted eating.
Learn More
You can subscribe to Dr. David Sinclair’s Lifespan Podcast to explore more on aging and longevity interventions starting January 5th, 2022.