Cycling Between Fasting and Feeding: A Key to Healthier Aging?
As we delve into the comprehensive research on aging, we often find ourselves puzzled with questions and challenges. One such riddle is how fasting interventions, seemingly beneficial in terms of health improvement, does not offer the same benefits in old organisms. To shed a novel light on this conundrum, researchers at the Max Planck Institute for Biology of Ageing in Cologne studied how older fish deviate from the youthful fasting and refeeding cycle. They discovered that by genetically activating a specific subunit of AMP kinase, old fish could regain the benefits of refeeding, leading to an increase in their healthspan and lifespan.
The Key Role of Diet in Aging
Diet isn’t just about maintaining a certain body weight – it also has far-reaching implications in terms of human longevity and how we age. Various studies on model organisms have shown that calorie restriction or periods of fasting can induce positive effects on health. However, these fasting benefits are not the same in humans due to the difficulty of sustaining a reduced diet throughout life.
Fasting Interventions and Ageing Killifish
Researchers from Cologne, Germany, ventured into investigating the age-related fasting effects in killifish, a rapid-aging fish species that provides a unique insight into the complex mechanisms of aging. By alternating their food intake between fasting and feeding twice a day, they observed that the visceral adipose (fat) tissue in old fish responded less to food intake, putting them in a state of perpetual fasting.
The Significance of Fasting, Feeding, and AMP Kinase
The team flagged that the adipose tissue’s failure to respond to the feeding phase was the cause of the old fish’s constant fasting state. Surprisingly, they remained in this fasting condition even while consuming food – an unexpected discovery that shifts our understanding of how fasting interventions function in older organisms.
Further investigations into the fatty tissue changes in fish revealed a critical protein: AMP kinase. The scientists found that by genetically boosting the activity of one of its subunits (the γ1 subunit), they counteracted the constant fasting state, leading to healthier and longer-lived old fish.
Human Ageing and the AMP kinase γ1 Subunit
Interestingly, this particular γ1 subunit links to human aging too. Lower levels of the subunit were found in elderly human samples, suggesting a potential connection between γ1 subunit activity and frailty in old age.
The search for healthier aging continues. Researchers express their intent to find molecules activating the γ1 subunit specifically to potentially positively influence human aging. It’s a profound wisdom that prompts us to view fasting not as a mere diet routine, but as a symbiotic dance with feeding – a rhythm we should fine-tune as we age, for a productive, long healthspan.
Main Takeaways
- Fasting interventions generally improve health, but their efficiency decreases in older organisms.
- Permanent fasting state, even when consuming food, was observed in older killifish due to their adipose tissue’s failure to respond to the feeding phase.
- The cellular energy sensor protein, AMP kinase, particularly its γ1 subunit, plays a central role in countering the permanent fasting state.
- Genetically activating the γ1 subunit led to increased healthspan and lifespan in older fish.
- Lower levels of the γ1 subunit were found in elderly human samples, hinting towards a possible link between γ1 subunit activity and frailty in old age.
Source Citation: https://www.sciencedaily.com/releases/2023/11/231113111829.htm
