42. Keto or DNA Sequencing?

Hi friends,

Welcome to the 42nd dispatch of How Humans Flourish, a research-informed newsletter on how humans thrive.

This month, we’ve been diving deep into Harvard geneticist Dr. David Sinclair’s groundbreaking book Lifespan: Why We Age—and Why We Don’t Have To, which reimagines our understanding of aging. Last week, we discussed the actionable steps we can take to extend our lifespan. This week we’re exploring the emerging technology that helps us do so as well.

Our DNA: The Key to Personalized Health

In 1990, the Human Genome Project launched and took a full decade to map just one human genome at the cost of billions of dollars. But today as Dr. Sinclair notes, “I can read an entire human genome of 25,000 genes in a few days for less than a hundred dollars on a candy bar–sized DNA sequencer called a MinION that I plug into my laptop.”

By decoding our individual genomes, our genes can tell us not only what diseases we are predisposed to, but also “what foods to eat, what microbiomes to cultivate in your gut and on your skin, and what therapies will work best to ensure that you reach your maximum potential lifespan.”

For example, genetic testing can help patients avoid harmful treatments by tailoring therapies to their specific biology. He mentions how “those who score in a certain range on a genetic test called Oncotype DX... respond every bit as well to hormone treatments as they do to chemotherapy, the latter of which has far more side effects.” This means fewer unnecessary interventions and more effective, personalized care. (Sinclair, pg. 225-226 - Kindle)

Biosensors and Real-Time Health Monitoring

The future of health is not just about understanding our DNA—it’s also about real-time data that helps us take action before diseases take root.

Dr. Sinclair writes, “We’ve already taken some pretty big steps into the age of personal biosensors. Our watches monitor our heart rate, measure our sleep cycles, and can even provide suggestions for food intake and activity.” But the next wave of innovation goes much further. He describes how researchers are developing devices that can provide detailed readouts of thousands of biomarkers—everything from the nutrients in our bodies to signs of stress or infection—straight from our sweat.

Soon, real-time diagnostics will allow us to detect diseases like cancer much earlier than we can today.

“With a simple blood test, doctors will be able to scan for circulating cell-free DNA, or cfDNA, and diagnose cancers that would be impossible to spot without the aid of computer algorithms optimized by machine learning processes.” (Sinclair, pg. 230-232 - Kindle)

Closing the Gender Gap in Health

Dr. Sinclair also addresses a critical issue in healthcare: the historical bias toward male biology. He explains, “For most of medical history, our treatments and therapies have been based on what was best for males,” leaving women at a disadvantage. However, with the inclusion of female test subjects in longevity studies, we’re beginning to see important differences in how men and women respond to treatments. (Sinclair, pg. 226 - Kindle)

For instance, treatments affecting insulin or mTOR signaling typically favor women, while chemical therapies often work better for men. By understanding these differences, we can ensure that women receive treatments that are truly effective for them—something that has been lacking in medicine for too long.

The Future of Precision Medicine

As we move further into the age of personalized health, Dr. Sinclair highlights the emerging field of pharmacoepigenetics, where “a patient’s epigenetic age will also be determined and used to predict drug responses.” (Sinclair, pg. 227 - Kindle)

Dr. Sinclair writes that, in the future, it will seem medieval to prescribe drugs without first knowing a patient’s genome. This will be especially important in developing countries, where the local genetics and microbiomes often differ drastically from those in the populations where drugs are tested.

With gratitude,