In a number of widely different species – yeast, worms, flies, mice – there’s a class of pharmaceuticals proven to slow aging and lengthen lifespan.
Many anti-aging researchers believe these drugs, called rapalogs, (the best known being rapamycin) hold out real hope for extending human life.
One of the researchers is Mikhail Blagosklonny, cell stress biologist at Roswell Park Cancer Institute, Buffalo, New York. To quote his very upbeat opinion, “Given that rapamycin consistently extends maximal lifespan in mice, rapamycin will likely allow mankind to beat the current record of human longevity, which is 122 years.”
Is he right? Let’s take a look. . .
In 2006 Dr. Blagosklonny proposed that aging and age-related diseases are caused by the overactivity of mechanistic target of rapamycin (mTOR).
These proteins act as the command and control center of the cell, signaling DNA which proteins to make. They are intimately involved in the aging process. Restraining mTOR with rapalogs, Dr. Blagosklonny suggests, will hold back aging and disease.
It’s one thing to demonstrate this ability in species that don’t live very long, but humans’ long lifespan makes a typical drug trial impossible. We can’t wait 50 years for results.
Testing The Concept in Humans
However, two studies have been completed that give an indication of the drugs’ potential. Both looked at the effect of low-dose, nontoxic mTOR inhibitors on the immune system.
The trials were led by Dr. Joan Mannick from Novartis Institutes for Biomedical Research in Cambridge, Massachusetts.
The first experiment tested a rapalog called RAD001.
Over 200 adults aged 65 and older received either the drug or a placebo for a few weeks, followed by the flu vaccine. Those on RAD001 had a 20% enhanced response to the vaccine, and they also benefited from the suppression of a receptor that lowers immune functioning in aging.
Commenting on the study findings, Dr. Nir Barzilai, director of the Institute for Aging Research at Albert Einstein College of Medicine in New York, believed this was a “watershed” moment:
“It sets the stage for using this drug to target aging, to improve everything about aging. That’s really going to be for us a turning point in research and we are very excited.”
I would call these results indicative, not “a watershed moment.” Enhanced response to a flu vaccine is a long way from proving people who take the drug can live to 120. All the same, it’s encouraging. . .and there’s more. . .
Infection Rate Plummets
The second study was published in Science Translational Medicine in July. For this randomized, double-blind, placebo-controlled trial, 264 volunteers aged 65 or over, with stable medical conditions, were divided into four groups.
The first took RAD001, the second took a different rapalog called BEZ235, the third took both and the fourth group took a placebo. These were taken for six weeks. After a further two weeks participants were given a shot of the seasonal flu vaccine.
When the researchers took stock a year later, the drugs, individually and in combination, were found to reduce the incidence of respiratory tract infections by between 36 and 42% compared to placebo, and infections of any kind by 33 to 38%. Participants also had an improved immune response to the vaccine and upregulation of genes that help fight off viruses.
Matt Kaeberlein, director of the Healthy Aging and Longevity Research Institute at the University of Washington, had this to say:
“This is an extremely important and exciting study. The mTOR inhibitors appear to broadly rejuvenate immune function in healthy elderly people. I think this study raises the real possibility that most middle-aged adults could benefit from short-term treatments with mTOR inhibitors.”
The next stage of research will be to test rapalogs on seniors with particular health conditions like diabetes or heart failure.
The aim being, as Dr Mannick puts it, to “keep everybody healthier and with a better quality of life as they grow older.”