Metformin and Beyond: Dr. David Sinclair on Learnings Since Lifespan

Harvard geneticist Dr. David Sinclair explores the science of aging, maximizing lifespan, metformin, and more in a Q&A session.

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By Staff Writer
Jovan Mijailovic
Edited by Jovan Mijailovic

Published May 12, 2024.

Dr. david sinclair portrait.

In this article

Who can benefit from intermittent fasting?

Which biomarkers should we track for longevity?

Do supplements affect aging?

Can we participate in endurance events while pursuing longevity?

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Dr. David Sinclair, a Harvard geneticist, co-founded the journal Aging and chairs InsideTracker's scientific advisory board. His achievements include 35 patents and numerous awards.

In his bestselling book Lifespan: Why We Age and Why We Don’t Have To, he explores the science of growing older and potential interventions. The following Q&A session addresses some of the most pressing questions in this field of research.



Who can benefit from intermittent fasting?

Intermittent fasting may not be suitable for everyone. It's generally inadvisable for:

  • Underweight people
  • Individuals younger than 18
  • Pregnant or breastfeeding women
  • Those with a history of eating disorders

If you have any pre-existing health conditions, especially diabetes, or take medications, consult your doctor before considering this diet.

Dr. Sinclair suggests that for most individuals over 30, eating three times a day might be excessive calorie intake. He points to research on long-lived animals and humans who don't eat constantly.

Skipping meals and experiencing short-term hunger (15-18 hours) isn't necessarily bad, says Dr. Sinclair, advocating for intermittent fasting.



» Find out more about life expectancy

Which biomarkers should we track for longevity?

Dr. Sinclair emphasizes individual optimization. "That's why I joined InsideTracker—to measure and track how dietary changes impact you," he explains.

Specifically, he focuses on biomarkers like fasting blood sugar, HbA1c, hsCRP, and cortisol to assess blood sugar control and inflammation—all of which you can find in the Ultimate Plan. He also highlights the importance of monitoring for deficiencies in B vitamins, magnesium, and sodium.

He also collaborated with InsideTracker on the InnerAge 2.0 Plan, a biological healthspan metric. The declining albumin levels with age and their potential toxicity contribute to aging," says Dr. Sinclair. He suggests it's the reason why plasmapheresis—removing blood plasma—appears beneficial in animals.





Do supplements affect aging?

Resveratrol—a natural compound in grapes, red wine, cocoa, and blueberries—has shown promise in slowing aging in preclinical studies. Dr. Sinclair suggests it activates SIRT1, a protein that protects cells from damage.

But, he also cautions that this supplement requires proper absorption. You need to take them with food so they can reach sufficient levels in the bloodstream and be effective.

» See what Dr. Han Nao's opinion on synthetic biology and lifespan

Can we participate in endurance events while pursuing longevity?

Yes. If you get it right, you're likely to live longer and healthier than someone who doesn't do either of those things.

But it's not easy to do both because you're putting yourself into a state of adversity. Dr. Sinclair emphasized that you should get to know your body on a deeper level through bloodwork. “The more you measure biomarkers, the better you can optimize your longevity strategy,” he says.

Can metformin hinder workouts?

Dr. Sinclair observes that combining metformin use with exercise can lead to reduced muscle growth. He attributes this to a potential dip in energy levels caused by this medication.

To optimize his training, he employs a personalized method, strategically alternating periods of metformin use with his workout routine. Dr. Sinclair also says that this isn't a one-size-fits-all solution and highlights the importance of tailoring one's approach based on individual needs.

» Live longer with our reliable biohacking strategies for lifespan

What’s the relationship between metformin and homocysteine?

While metformin offers benefits, Dr. Sinclair highlights a potential concern: increased homocysteine. Elevated levels of it relate to heart disease and may hinder DNA methylation, a process that impacts aging.

He advises monitoring this amino acid for those taking metformin to ensure they stay within a healthy range.



» Check out biological age: a predictor of your longevity

Any new insights since you wrote Lifespan?

Dr. Sinclair acknowledges that his understanding of diet's role in longevity has evolved since publishing his book. He emphasizes the positive impact dietary changes, particularly a plant-based approach with minimal dairy, have had on his own health markers.

Additionally, Dr. Sinclair highlights his published research on epigenetic reprogramming, a topic still under investigation during the writing of Lifespan.

Since its publication in Nature Magazine (2020), the information theory of aging—a concept linked to epigenetic reprogramming—has gained significant traction within the scientific community.

Lifespan is essentially a textbook for longevity, and is the basis of what I and you at InsideTracker do.

» Explore recent trends in longevity research

What's next for Dr. Sinclair?

Dr. Sinclair’s team is investigating the next generation of drugs. They're in the process of developing curing blindness through gene therapy, as mentioned in Lifespan. He's also working on medications to reverse aging.

This would be the ultimate dream: to take pills for a few weeks and go back decades in time.

He's also is in the process of writing his second book, which should hopefully debut next year. And he is looking forward to season two of his wildly successful podcast that’s aptly named Lifespan.

Until the next major breakthrough, InsideTracker can help you take charge of your health and optimize your healthspan through personalized insights and science-backed recommendations.

Disclaimer: InsideTracker doesn't treat or diagnose medical conditions. Consult your physician for any health concerns.