These 70-year-olds in Arizona are about to give the biggest performance of their lives. | Photo: Kendrick Brinson for 1in6by2030

When my 56-year-old uncle was diagnosed with late-stage cancer, he decided against radiotherapy and chemotherapy. He wanted to live freely for as long as he had left. He enjoyed his final months – and it was only in his very last few days that he was no longer out and about as had always been his custom until then.

I admired him back then, and still do. It was clear to him that he didn’t just want to survive for a few months more. No, he wanted to savour to the full the brief time that remained to him. And it’s this dilemma that’s at the heart of the ethical issues that arise when we consider how we want to grow old. Should we aim to live longer, or just enjoy the rest of our life? The concept of longevity is all about reaching the highest possible age as healthily as possible. We try out drugs, we engage in intensive sports, and we avoid many things too. Manuel Puntschuh is a doctor, and he explains in a Feature article in this issue that “I’m constantly working on optimising things in myself”. He also relies on scientific findings gained from research on animal models – although this is a rather flimsy basis for medical applications in humans. There’s no robust evidence, for example, that taking antioxidants or restricting our calorie intake – both of which help threadworms and mice to live longer – might have a direct impact on any one of us as we grow older.

And there are people with very contrary opinions too. In the same Feature article, the 72-year-old author and director Katja Früh says, “I don’t think it worth living if you have to mortify the flesh to do so. Of course, you shouldn’t ruin yourself through overindulgence. But I think it’s wonderful to enjoy life’s pleasures”. She presumably isn’t going to let science get in the way of enjoying life. After all, many studies have shown that smoking, drinking and doing little exercise all reduce average life expectancy.

But whether or not scientific evidence is strong or weak, does this really have to play a role when we plan the end of our lives? In my opinion, no one has a right to dictate the terms of our end to anyone, regardless of their own stance in this matter. Whether or not people engage in moralistic finger-wagging or insist on rigid societal norms, and whether or not we apply stereotypical medical models or recent scientific findings, it isn’t appropriate for anyone else to determine how we should make what is ultimately a purely personal decision.