Extending the Range of Health by Extending Telomeres: A Profile of Liz Parrish

Patient zero

Liz Parrish was nervous. She was on a plane to Colombia, where she would undergo an untested gene therapy. She and her colleagues had spent two years developing the therapy and preparing, but they didn’t know how it would work.

It was September 2015, and Parrish was inspired to take this step because her son, who suffers from type 1 diabetes, could not get treatment for his condition in the US. She decided to embark on a mission to convince the FDA to switch from a precautionary approach to a proactive one. It’s a mission she still pursues today.

Startling results

Treatment consisted of two intravenous injections and was uneventful. A few weeks of waiting for the results followed. The report was startling. Before treatment, the biomarkers used by Parrish showed her biological age to be 66, a full 22 years older than her chronological age. (Your biological age describes the state of your body relative to your peers; your chronological age is simply the number of trips you’ve made around the sun). After treatment, her reported biological age dropped to her actual age.

Parrish repeated the treatment in 2020, and she reports that since 2015, her biological age has decreased by an average of five years each year. It dropped sharply again after the second treatment and is now remarkably below 25.


Parrish is making this data publicly available, but her approach has proven controversial. George Martin, a professor of pathology at the University of Washington, was an adviser to Parrish’s company BioViva, but resigned when he learned of the trip to Colombia. Maria Blasco, the Spanish scientist whose pioneering work underpins Parrish’s treatment, insists that therapies should not be used without rigorous trials validated by the FDA and other regulatory agencies.

Parrish is unrepentant. She does not dispute the need for medical practice to be as safe as possible, but points out that it can never be completely risk-free. “People are killed by regulated drugs all the time.” The type of therapy she uses has been producing extraordinary results in mice for more than a decade. Of course, mice and humans are very different species, but the therapy has also been shown not to harm human cells. Parrish cites data from the World Health Organization: “41 million people are currently dying from non-communicable diseases associated with aging. We can save them. We have to stand on the right side of history.”

In the years since her treatment, Parrish has met with presidents, health ministers and politicians around the world. There is great interest in her arguments, but there is also a fear of overstepping. Parrish hopes that one way this resistance can be overcome is by providing new therapies to end-of-life patients without the usual testing—patients who have tried every approved approach and have no other alternative.

Medical tourism

It takes decades and billions of dollars to bring a new drug to market, meaning many promising therapies are never given a chance. (There are promising signs that AI can help reduce these times and costs.) One result of this is the rise of medical tourism, with patients traveling to clinics outside the jurisdiction of the FDA and similar agencies. Many of these clinics are reputable, professionally run institutions, but others not so much. Parrish argues that the existence of medical tourism is a sign that something is wrong in the medical establishment, and she also notes that 80% of medical trials conducted by big pharmaceutical companies are conducted offshore.

There’s no way of knowing how many people have followed in Parrish’s footsteps, but she thinks it’s a lot. Given the remarkable results she reports, it’s perhaps surprising there haven’t been more.


The main gene therapy treatment Parrish underwent was designed to lengthen her telomeres. (She also took a myostatin inhibitor, which fights muscle wasting.) Our genes are made up of intertwined strings of DNA molecules called chromosomes. When our cells divide, these strings would break if it weren’t for the protection provided by telomeres. Telomeres are stretches of DNA that repeat information and are therefore exhaustible. When a cell divides more than a certain amount (the so-called Hayflick limit, which is usually 50 to 70 times), the telomeres are effectively depleted and the chromosome itself is damaged. A substance called telomerase can prevent this breakdown and preserve the genetic stability of the cell.

Parrish’s reduced biological age is measured by the number of telomeres in her white blood cells—specifically, in her T lymphocytes, a type of white blood cell that plays an important role in the body’s immune response.

Gene therapy is delivered using viruses known as ‘vectors’. The therapy Parrish used in 2015 used a vector called AAV, and her company is now working on another vector called cytomegalovirus (CMV). Both technologies occur naturally in humans and monkeys and can deliver genes that produce telomerase without changing the genetic makeup of the chromosome. But CMV can deliver larger genetic payloads than AAV, and BioViva is now designing therapies that use multiple genes to control the aging process. BioViva is working with Rutgers University to improve this technology and holds some patents as a result.

Parrish doesn’t believe that lengthening telomeres is the most important thing in the fight against aging. There are long-lived species whose telomeres shorten rapidly and vice versa. Human biology is extremely complex and aging will not be defeated by a single silver bullet. But she is confident that lengthening telomeres plays an important role in the fight.

An exciting future

Parrish is enthusiastic and optimistic. If governments don’t find a way to accelerate the adoption of new health care techniques, she worries that a health divide will develop, where people who can afford the fees and travel costs associated with medical tourism will enjoy a significantly lower -good health outcomes from those I can’t. But if governments do rise to the challenge, she envisions a future – just a decade or two in the future – where people will enjoy a healthier old age and then begin to live longer. She exhorts us all to “get excited about the future!”

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