David Sinclair

Researchers began to cautiously agree: address these hallmarks, and you can slow down aging. Slow down aging, and you can forestall disease. Forestall disease, and you can push back death.

Take stem cells, which have the potential to develop into many other kinds of cells: if we can keep these undifferentiated cells from tiring out, they can continue to generate all the differentiated cells necessary to heal damaged tissues and battle all kinds of diseases.

Here’s the vital takeaway: we could age mice without affecting any of the most commonly assumed causes of aging. We hadn’t made their cells mutate. We hadn’t touched their telomeres. We hadn’t messed with their mitochondria.

stem cells. Yet the ICE mice were suffering from a loss of body mass, mitochondria, and muscle strength and an increase in cataracts, arthritis, dementia, bone loss, and frailty.

All of the symptoms of aging—the conditions that push mice, like humans, farther toward the precipice of death—were being caused not by mutation but by the epigenetic changes that come as a result of DNA damage signals.

We hadn’t given the mice all of those ailments. We had given them aging.

And if you can give something, you can take it away.