How we age: The surprising secrets to a long life
This story was first published on November 12, 2022 and has been resurfaced as the Listener brings back its best health features.
The keys to good health well into old age are in our hands, says a youthful scientist who advocates diet and exercise – and a little of what’s “bad” for us.
On the hottest day of September in 1991, eight adult volunteers sealed themselves into a three-acre geodesic glasshouse in the red earth of Oracle, Arizona. The four men and four women, self-confessed hippies, had day jobs in experimental theatre, farming and furniture-making, but their shared mission was to create an exact ecological replica of the Earth, complete with forests, deserts and even a living coral reef. It was called Biosphere 2.
Several strange things happened in the two years they spent locked inside this sci-fi complex – oxygen deprivation, warfare between two groups, and a desperate lack of food – but there was something else going on in the rainforest biome. Free of pesticides and wind, trees grew quickly and lusciously. Yet, despite their near-perfect conditions, once mature, they toppled over and died.
The problem wasn’t overwatering or a virus. It was stress, or more specifically a lack of it. Without wind, the trees were unable to grow “stress wood”, an important part of the ageing process that hardens the tree trunk and supports its full size.
In his bestselling book Jellyfish Age Backwards: Nature’s secrets to longevity, Nicklas Brendborg, 27, a rising star in molecular biology with an MA in biotechnology from the University of Copenhagen, says stress is one of the keys to living a long and healthy life. This is not the stress of working long hours and being busy: it’s the specific tension we place on our cells when we give them small doses of toxins or “survivable stressors”. Cells in recovery are better at repair and maintenance, reduce bodily inflammation, and improve blood sugar regulation.
The scientific word for this process is hormesis. Brendborg says it may explain why a study of Taiwanese apartment dwellers accidentally exposed to background radiation from contaminated steel found they had fewer cases of virtually all types of cancer than the general population. In the US, studies have found that people living in areas with higher-than-usual background radiation levels live longer than average. Hormesis could also explain why blood donors live longer by losing blood, reducing their levels of iron in the process (more on that later).
One way to induce hormesis is through diet. Edible plants release toxins that are harmful to us in high doses, but in moderation work as an effective cellular wake-up call. Foods high in polyphenols, such as chillies, artichokes, pineapples, onions and wild almonds (the latter containing traces of cyanide), all challenge our system at the right dosage.
In his book, Brendborg suggests another way to activate hormesis that has a striking effect on longevity, with a study showing those who do it regularly are 80 per cent less likely to die prematurely. It involves a complex combination of dramatically raising our heart rate and blood pressure, burdening muscles and bones, and increasing the production of free radicals – what Brendborg refers to as the cellular version of a “bull in a China shop”. This potent mix of hermetic stress is exercise, and it’s one of the most powerful anti-ageing drugs available.
Racing the clock
It’s impossible to talk about longevity without addressing the elephant in the room: who wants to live long if you are unable to enjoy the extra time? No one wants to be in the body and mind of a centenarian for an extra 50 years.