David Suzuki at Ron Zalko’s gym in Vancouver. He says too much lab work had led to a pot belly.
It is a terrible irony that humankind's efforts to engineer a delay to the aging process may consume vast quantities of time, money and hope, while an answer is already before us.
This week, a Harvard study of lab mice, published in the prestigious journal Nature, reported that the seemingly impossible had been achieved: Aging had been turned back.
If the same could be done for human beings - if a 60-year-old could resemble, in overall health, today's 53-year-old - the consequences would be huge. Imagine a world of "compressed aging" in which people have more healthy years, and fewer infirm ones, even if they live not much longer than they do now. Compressed aging could provide an answer to rising health costs, burdensome pensions and the need to care for vast numbers of disabled elderly around the globe.
But the Harvard study was fraught with caveats, while the alternative is more straightforward, even if people are tired of hearing about it. Exercise. The cutting-edge science may surprise people.
Take a man or woman, age 65 or even 70, who has been sedentary for decades. Let him or her do weight-training exercise, not jerking heavy barbells but doing lots of repetitions with light weights, for as little as four months. The result? A reversal of the aging process similar to that found in the Harvard lab mice.
The Harvard study focused on an enzyme thought of as a fountain of youth: the telomerase. Telomerase lengthens the telomeres, caps on the ends of chromosomes that, like plastic tips on a shoelace, protect them from damage associated with aging. Turn off this enzyme in mice, and the mice deteriorate. Their brain shrinks. Their fertility is lost. Turn the enzyme back on, they become young again. Even their brains grow.
Now the caveats. These were prematurely aged mice. Does reinvigorating the enzyme in cells where it no longer works apply beyond those with diseases involving premature aging? Maybe not. Even if it does, will it stimulate the growth of cancer cells? Quite possibly.
Consider what exercise does to telomerase and telomeres - much the same thing as was achieved with the Harvard mice.
"The telomere length in athletes is longer," says Mark Tarnopolsky, an expert in neuromuscular diseases at McMaster University's medical school in Hamilton. But you don't need to be an athlete to benefit. Exercise "protects against this telomere shortening and increases telomerase activity." Exercise, then, does more than make people fit. It also slows or reverses the aging process.
"We looked at what's called gene-expression patterns - at how all of our genes are being expressed in young persons versus old (just over 600 genes were different) - and we reversed a third of those genes, so they went right back to normal," says Dr. Tarnopolsky, whose studies have been financed by the Canadian Institutes for Health Research.
Taking a pill would be easier. But exercise, at least for the foreseeable future, is a far more practical route to compressed aging. And that is a good reason for our society to give far more serious thought to fostering exercise - in all ages - than it has ever done before.