For much of history, people sought to halt ageing to achieve immortality – or at least to live for hundreds of years. These days, scientists tend to have more modest aims. In wealthy nations, basic healthcare and medical advances have driven up lifespan for the past century. Five years from now, for the first time in human history, there will be more over-60s than children under five years old. In 2050, two billion people will be 60 or older, nearly double the number today.
Behind that statistic lies a serious problem. People are living longer, but they are not necessarily living better. The old struggle with chronic conditions, often many at once: cancer, respiratory disease, heart disease, diabetes, arthritis, osteoporosis, dementia.
Medical researchers tend to tackle these diseases separately. After all, the illnesses are distinct: cancer arises from mutated DNA; heart disease from clogged up blood vessels; dementia from damaged brain cells. The biological processes that underpin the pathologies vary enormously. Each, then, needs its own treatment. Yet some researchers take another view: the greatest driver of disease in old age is old age itself. So why not invent treatments for ageing?
The idea has caught on, though it is still far from mainstream. Google’s secretive Calico operation, founded in 2013, is putting hundreds of millions of dollars into anti-ageing research. Craig Venter, the genetics entrepreneur, has launched a company called Human Longevity to find the genes that lead to long life. Meanwhile, scientists have asked the US Food and Drug Administration to approve trials of well-known drugs, such as the diabetes treatment, metformin, in the hope of uncovering anti-ageing effects.