EXTENDING YOUR LIFE
Could diabetes drug lead scientists to longevity’s ‘Holy Grail’?
Our life expectancy at birth has risen from roughly age 50 to 80 in the past century, a dramatic increase considering that for hundreds of years the human expiration date had been constant, hovering somewhere around 40.
So why do some scientists want us to stop aging?
The reason is they believe aging is the single biggest risk factor for diseases such as cancer, Alzheimer’s and Type 2 diabetes — conditions that were less of a concern before public health improvements such as clean water, vaccines and medication helped us live longer.
If scientists can find a way to slow the aging process, they believe they can delay the onset or progression of a number of those illnesses.
Scientists have already used a drug called rapamycin, as well as manipulated a gene, to extend the life of mice by 10 per cent to 30 per cent. The mice not only lived longer than their typical three years, but they were also in better health, which is really the goal of modern aging research, says Judith Campisi, a cell and molecular biologist at California’s Buck Institute for Research on Aging.
Now researchers in the U.S. and Canada want to hold the first anti- aging clinical trial to see if they can replicate the same effect in humans using a diabetes drug called metformin.
While there is no guarantee that metformin will be successful, the research is part of the quest for the Holy Grail in the fight against aging.
The proposed metformin trial doesn’t require approval by the U.S. Food and Drug Administration (FDA) to proceed, but researchers are asking the agency to comment on how it should be conducted because the FDA decides how a drug is labelled and sold.
If the trial goes ahead next year, and if it’s successful, the agency has agreed to label metformin as a treatment for a number of age-related illnesses. It is already sanctioned to treat Type 2 diabetes, after being approved for that purpose in Canada in 1972 and in the U.S. in 1994.
But the label won’t mention antiaging.
“Neither (the FDA) nor us want to say aging is a disease,” says Nir Barzilai, director of the Institute for Aging Research at the Albert Einstein College of Medicine in New York City. Barzilai, who is the trial’s lead investigator, says instead, “I think of the biology of aging as the risk factor for all of those diseases, and that’s what we want to target.”
The trial could clear up years of uncertainty about the efficacy of metformin as a potential miracle drug.
A decade ago, a study concluded that diabetics taking the drug who then got cancer had a lower than expected risk of death.
In the years since, there have been dozens more studies, but roughly half have failed to reproduce the same findings, says Michael Pollak, an oncologist and professor at McGill University.
In the lab, though, metformin has consistently been shown to slow the rate at which cancer cells divide, says Pollak, who tested the drug in his lab eight years ago. He is the only Canadian involved in the proposed trial.
More recent studies show the drug may suppress chronic tissue inflammation, which is present in almost all of the age-related diseases and which researchers believe could be a common pathway to disease, according to Campisi.
If scientists can find a way to interrupt the pathway, they may be able to stall the disease, Campisi says. “There’s reason to believe the field is correct in looking for this Holy Grail.”
(Scientists in Scotland started a trial this year to see if metformin can prevent Type 1 diabetes.)
If the U.S. trial is successful, metformin or another drug like it could change the way patients are treated, for instance by decreasing inflammation in an elderly person before and after a hip replacement.
It could also create roles for doctors who specialize in treating several diseases of aging, Campisi says, and replace the “silo approach” to treatment.
“Now people working on aging are thinking we need a brand of physician who is going to look at the much larger picture,” Campisi says. She is featured in The Longevity Book, published this spring and co-authored by actor Cameron Diaz and writer Sandra Bark, which deals with the latest aging research.
A trial could also create strict parameters for future research on antiaging drugs, which often attract charlatans.
“I have to say outright that a very important take-home message for your readers is that there’s a huge amount of quackery,” Pollak says.
He notes that after research in the 1990s on human growth hormone, the drug began proliferating as an anti-aging formula — one that could purportedly turn back the clock and help build muscle, increase stamina and reduce wrinkles.
Pollak says the hormone does make people produce more insulin-like growth factor 1, which stimulates cell division as well as an increase in cell size.
But “the best research predicts that you will actually age more quickly because all your rates of cell division are higher,” he says.