The quest for eternal youth is the stuff of sci-fiand legend. For thousands of years, people have been seeking ways to stave off death. China’s first emperor, Qin Shi Huang, was famously obsessed with finding an elixir to prolong his life but died in 210BC at age 49, ironically, it appears, after consuming a would-be immortality potion that turned out to be toxic.

Today, the average life expectancy in New Zealand is 81.86 years. Live that long and no matter how healthy your habits, your body will have deteriorated. Many of your cells will have exhausted their ability to divide and will have become senescent. Those that survive will be too worn out to do their job properly.

You will lose muscle mass and strength. Your immune system will start failing to protect you from infection and instead fuel chronic inflammation. Proteins will start to misfold and clump, forming the amyloids associated with Alzheimer’s. Your microbiome will change. Your DNA will be damaged.

Blame evolution, which is only interested in keeping us strong and healthy during our reproductive years and has engineered a lot of biological trade-offs to ensure that happens.

According to Andrew Steele, we are on the cusp of all that changing. He believes most of us will live long enough to benefit from some sort of treatment that will extend our “healthspan” as well as our lifespan.

Steele is a computational biologist with a PhD from Oxford University who used machine learning to decode human DNA. For the past three years, he has been working on a new book, Ageless: The new science of getting older without getting old, looking at the cutting-edge research happening around the world with the bold aim of curing ageing.

Modern humans live in a kind of lab environment of our own devising. So we’ve got scope to tweak our biology.

“The ideas for treating ageing aren’t pie-in-the-sky theoretical biology –