Of mice and men

It was a huge come-down for post-docs researching into biological roots of longevity. Here they were chugging along nicely in a top-flight lab, expecting to uncover Nobelworthy discoveries. Then came the mice. As the poet Robert Burns sang in his poem, the humble creatures upset the best-laid schemes of men, even as they rewrote their own mousey lives on the treadmill.

The mice had been genetically altered to age faster and literally fall apart with decrepitude in just eight months. But these mice had glossy pelts, strong muscles and no signs of age at all as the months went by. The secret of their youth turns out to be plain old exercise : the über athletes had been subjected to reasonably challenging exercise three days a week in the lab: 45 minutes per session at the equivalent human pace of running an 8.5-minute mile. The result was absolutely astounding.

The control mice were nearly crippled by old age by eight months, about 60 or so in human years. Not one animal from the sedentary group lived past one year. In contrast, the robust ratracers showed little to no signs of deterioration in brains, follicles , or gonads. They acted liked teenagers, balancing on little rods, and by the end of the year none of them had died of natural causes.

Though they all had the mutation blocking cell repair, the athletic mice had generated enough normalcy to overcome their genetic destiny. The moral of their saga was simple: exercise alone alters the course of aging. Finally, it was the size of the mice gonads that goaded the post-docs to run for their lives.