#171 - Steve Austad, Ph.D.: The landscape of longevity science: making sense of caloric restriction, biomarkers of aging, and possible geroprotective molecules

Aug 9, 2021 2h 26m 11 insights

Steve Austad is a distinguished professor of biology at the University of Alabama and director of one of the Nathan Shock Centers of Excellence in aging biology. Steve's current research seeks to understand the underlying causes of aging, specifically with a long-term goal of developing medical interventions that slow the age-related decay of human health. In this episode, Steve tells Peter about his unusual childhood and stints as a cab driver and lion tamer. He goes on to describe what led to his focus on studying aging and some of the major challenges and limitations of working with laboratory animals. Steve and Peter talk about the relationship between caloric restriction and lifespan, including some of the most important studies exploring this question. Additionally, they hypothesize what might explain the sex-related differences in longevity between men and women, explain the importance of finding longevity biomarkers, and discuss the most promising molecules as potential longevity agents. We discuss: <ul> <li>Steve's background and unusual childhood [2:30]; </li> <li>Steve's adventures driving a cab in New York City [9:00]; </li> <li>How Steve drove to LA and accidentally became a lion tamer [13:30]; </li> <li>How Steve's early graduate school experiences led him to study longevity [23:00]; </li> <li>The challenges and limitations of working with lab mice [30:45]; </li> <li>The connection between caloric restriction and lifespan [43:00]; </li> <li>Mice vs. rats and rodent aging experiments [51:15]; </li> <li>The impact of dietary composition and the harm of sucrose: Comparing two caloric-restriction studies in monkeys [56:00]; </li> <li>Challenges of studying animals due to major differences in the lab animal vs. wild animals [1:10:00]; </li> <li>Human studies of calorie restriction [1:24:45]; </li> <li>Better dietary protocols for humans: Alternatives to long-term caloric restriction [1:33:45]; </li> <li>The protective effect of fasting [1:38:00]; </li> <li>Reflecting on the sex differences in human lifespan, and why women have more neurodegenerative diseases [1:45:45]; </li> <li>The importance of identifying longevity biomarkers and which ones show the potential to change the landscape of longevity research [2:03:30]; </li> <li>Molecules showing the most promise as longevity agents [2:14:00]; and </li> <li>More.</li> </ul> Learn more: https://peterattiamd.com/ Show notes page for this episode: <a href="https://peterattiamd.com/SteveAustad">https://peterattiamd.com/SteveAustad</a> Subscribe to receive exclusive subscriber-only content: https://peterattiamd.com/subscribe/ Sign up to receive Peter's email newsletter: https://peterattiamd.com/newsletter/ Connect with Peter on Facebook | Twitter | Instagram.

Episode Page ↗

Actionable Insights

1. Improve Health at Any Age

It’s never too late to significantly improve your health; even if you’re 50 and have a history of poor diet and no exercise, you can still achieve substantial health benefits. This challenges the notion that past habits dictate future health outcomes.

2. Focus on Diet Quality Over Quantity

The quality of your diet, specifically reducing harmful components like sucrose, may be as important or more important than caloric restriction for health benefits. The worse the diet, the more beneficial caloric restriction becomes, while a healthy diet reduces the impact of further restriction.

3. Short-Term Fasting Boosts Resilience

Engaging in short-term fasts (e.g., 2-3 days of water-only fasting, as seen in mouse studies) can significantly improve the body’s ability to recover from severe injury or stress. This suggests that transient periods of fasting can induce robust protective benefits.

4. Consider Episodic Rapalog Dosing

For potential immune boosting and longevity benefits, consider episodic dosing of rapalogs (like everolimus at 5mg or 20mg once a week). Lower doses have shown effectiveness in enhancing vaccine response in older adults with fewer side effects.

5. Metformin for Broad Health Benefits

Metformin, an extremely safe drug taken by millions, shows compelling data from human studies (beyond mouse data) for a wide range of benefits including reduced risk of dementia, cancer, and heart disease, making it a promising candidate for geroprotection.

6. Combine Geroprotective Interventions

Combining different geroprotective molecules or strategies, such as rapamycin and metformin, may offer synergistic and more helpful health benefits than single interventions alone.

7. Avoid Extreme Constant Caloric Restriction

While some caloric restriction can be beneficial, constant and extreme caloric restriction (like that practiced by ‘cronies’) is not the answer for most people. It can lead to negative side effects such as low bone mineral density, negligible sex hormones, and loss of muscle mass.

8. Exercise to Maintain Muscle Mass

If practicing caloric restriction, it is crucial to exercise more to counteract the tendency to lose muscle mass. Individuals on restrictive diets often struggle to maintain adequate muscle.

9. Accumulate Diverse Life Experiences

Actively seek out and accumulate a wide range of life experiences and adventures. This approach can broaden your perspective and provide unique insights, as demonstrated by Steve Austad’s varied career path.

10. Skepticism of Single Mouse Studies

When evaluating scientific claims, especially in longevity, maintain skepticism towards findings based solely on a single mouse study. These findings may not be generalizable or replicable in humans due to genetic and environmental differences.

11. Caution with Epigenetic Age Clocks

Be cautious about relying on current epigenetic age clocks as definitive clinical biomarkers. They are highly sensitive to short-term changes and easily manipulated, making their long-term clinical utility questionable.