A new test claims to tell how well you are ageing and even when you will die. But I would rather not know. Helen Pilcher explains why she prefers to leave new methods to measure biological age to the Kardashians, as too much knowledge about your mortality can be bad for your health.
The Kardashians and Biological Age
In the season 5 finale of The Kardashians, the family took a commercially available blood test to discover how fast their bodies were ageing. Unsurprisingly, given their privileged lifestyles, the reality TV stars were said to be ageing more slowly than most mortals of the same age. Khloé, then 39, found she had a biological age of 28, prompting whoops of joy and smugness. The Kardashians join a growing list of celebrities who have taken similar tests and then crowed about their biological ages. Now, there is a new test on the block.
What Is Biological Age?
Chronological age is the number of candles on your birthday cake. Biological age is a measure of the health of your cells and organs. The new method, devised by Vadim Gladyshev from Harvard Medical School and colleagues, not only provides a measure of biological ageing but also a time to death. Who wants to hand over a sample for analysis? Definitely not me.
Molecular Clocks and Age Estimation
Researchers have been devising so-called molecular clocks to estimate biological age for more than a decade. The problem they are trying to solve is that there is no objective measure for age – humans do not have tree rings – so researchers pick something that they can measure, that seems to change with age and that may also say something about the person's general health. It is kind of like using tooth wear and tear to predict a dog's age: you get a ballpark estimate of how old they are, as well as a vague indication of how well or otherwise the pooch is. The most famous one, known as the Horvath clock, is based on epigenetics – the pattern of chemical tags attached to DNA.
Gladyshev's Method
Gladyshev's method is based on patterns of gene activity, collected from more than 4,000 people to establish how the patterns relate to age and disease, as well as looking at data from mice, rats and macaques. The researchers believe this method is more sensitive than its predecessors. By providing a reliable measure for ageing, the test could shorten the otherwise lengthy clinical trials needed to tell if anti-ageing treatments work. The method could also be used to inform age-related policy. Current ageing policies are based on chronological age, but the Kardashians seem to show us that some people age differently to their peers. Future policy could be adjusted to match this reality, if the tests are accurate.
Why I Would Not Take the Test
For now, the test is for research purposes only. But should a spin-off version become publicly available, I still would not want it. Based on data from vast numbers of people, tests such as this provide estimates of probability rather than definitive predictions. They cannot actually tell you the day you will die, or state with certainty what health problems you will develop. Instead, they assess how closely your molecular profile resembles others in their datasets. Then they infer your likely risk of disease or how long you might have before death based on what has happened to people with similar characteristics. I do not need this kind of statistical high jinks to tell me I could be ageing better. I am aged over 50. I eat biscuits. I do not exercise as often as I should. I already know what I need to do to improve my health and prolong my life – eat fewer biscuits, exercise more – I do not need a test to make me feel bad for not doing it.
The Power of Beliefs
In addition, I am worried that a negative result could change the way I think about my future. As things stand, I feel good about getting older. I cannot be doing with anything that challenges this view, because I know how physically transformative beliefs can be. The research of Yale University's Becca Levy, for example, has shown that when people expect old age to be pockmarked with frailty and decline, it becomes more likely to happen. In later life, they are more likely to suffer from cardiovascular problems and memory loss. In another study, researchers interviewed 660 people over 50 from the small town of Oxford, Ohio, about their attitudes to ageing. Following up more than a quarter of a century later, Levy tallied the responses with data from the US National Death Index. Factoring in related risk factors, she found that those who had a negative view of ageing died, on average, 7.5 years earlier than those who held positive beliefs about ageing.
Beliefs Become Biology
The emerging idea is that beliefs about ageing do not just stay in the mind – they can become biologically embodied. Over time, changes in behaviour, stress hormone levels and immune system function can accumulate to influence physical health, ageing and longevity. In this model, anything that taints the expectations we have of our own ageing has the potential to influence the way that we age and, as a consequence, the timing of our death. So, my plan is to live as healthily as I can and avoid anything that might rock my rosy view of retirement. As for tests of biological ageing and mortality risk, I will leave those to the influencers. I am quite happy not to keep up with the Kardashians.
Helen Pilcher is a science writer and the author of This Book May Cause Side Effects.
