A Twitter thread by David Sinclair caught my eye recently, exploring a fascinating question: why doesn’t our body keep its repair systems running all the time, even during times of abundance? His answer links evolutionary biology with modern health strategies and offers profound insights into how we can live healthier, longer lives.

Let me break it down in my words:

1. The Trade-Off Between Survival and Longevity

In times of plenty, our bodies prioritize storing energy over repairing cells. Why? Because survival in our ancestors’ world often depended on how much energy they could save for lean times. Starvation, infections, injuries, and violence meant life expectancy rarely exceeded 50 years. Immediate survival trumped long-term health because, frankly, many never got the chance to benefit from longevity.

2. A Legacy That No Longer Serves Us

Fast forward to today. Our world is one of abundance. We no longer need to hoard energy in the same way, but our biology hasn’t caught up. Instead, this tendency manifests as obesity, metabolic disorders, and chronic diseases. We’re programmed to store, not repair—an evolutionary advantage that’s become a disadvantage in modern times.

3. Simulating the Challenges of the Past

Here’s the twist: our bodies are still wired to respond to adversity. This means we can “trick” our biology into activating repair mechanisms by mimicking the hardships of our ancestors. How? Through intermittent fasting, intense exercise, exposure to temperature extremes, limiting certain amino acids, and avoiding sugar. These practices signal scarcity and stress, forcing our cells to repair and optimize for survival.

4. The Science of Aging: Disposable Soma Theory

Sinclair ties this idea to Tom Kirkwood’s Disposable Soma Theory. Kirkwood suggests that aging isn’t inevitable but a result of how organisms allocate resources. Evolutionarily, reproduction was the priority, so energy spent on longevity wasn’t as essential once offspring were produced. Today, however, we can afford to shift that balance—prioritizing repair and health rather than reproduction and survival.

5. A Call to Action for Health and Longevity

This interpretation of biology resonates deeply. It reframes how we approach health in a world of abundance: we don’t need to hoard; we need to challenge. Stress your body (in controlled ways), and it will respond by repairing itself, enhancing resilience, and slowing down aging.

In a way, it’s about respecting the wisdom of our biology while using the knowledge of our present to outsmart it.

Final Thoughts

What David Sinclair reminds us of is both empowering and sobering. Aging isn’t just about time—it’s about how we use the time we have. By integrating these insights into our daily lives, we can align our biology with our modern reality, moving from survival to thriving.

It’s fascinating how a single thread can spark such deep reflection, isn’t it?