• Opting Out of Infirmity

    For most of the twentieth century, in the UK at least, as people progressed through their sixties their bodies generally started showing the typical signs of ageing. By the time they hit 70 they would typically find themselves frail, wrinkled and stooped. When my grandparents were in their sixties they looked very old, so I had assumed this process was an inexorable fact of life. Yet this has not happened as my parents have progressed through their sixties. Rather than the passage of the years stripping the youth from my parents bodies, if anything they seem only to get fitter and stronger; in body and mind. They are in their mid-sixties, yet my dad’s six pack is better than mine and my mum’s musculature is in better shape than when she was in her twenties. And she’s still razor sharp when it comes to correcting my mispronunciations and misspellings. This begs the question: what exactly have they been doing so right that previous generations seemed to get so wrong?

    I’ve been digging around in the science literature to find some clues as to whether people really are ageing better these days in terms of body as well as brain. If so, I wanted to know what lifestyle choices can make the difference between vigour and decrepitude. Is down to a better diet? My parents certainly eat very healthily. A meal at their place invariably involves lean meat or oily fish with plenty of veg ever since it emerged that a Mediterranean-style diet is associated with better health. Or could it simply be down to levels of air pollution? When my grandparents were middle-aged we were still happily pumping CFCs from every aerosol can out into the atmosphere in such large quantities that there was a huge hole in the ozone layer (happily since CFCs were banned this situation seems to have improved) and all the petrol we put into our cars contained lead that was then pumped out of exhaust pipes on every road across the nation (which is no longer the case). My parents also keep very active both physically and mentally, my grandparents did not, so another possibility is that their physical fitness and/or regular engagement with activities that keep them mentally sharp could play a role.

    A recent review paper by Luis Bettio and colleagues at the University of Victoria in Canada outlined the various factors known to accelerate cognitive decline. Cognitive decline involves problems with the ability to recall details of events, where things are in space, holding several pieces of information in mind simultaneously, maintaining focus and noticing relevant sensory cues (e.g. keeping track of other cars in peripheral vision while driving). All these functions rely heavily on the hippocampus. This structure, which has been mentioned in several previous blogs, is a seahorse-shaped hub of densely-packed neurons that create and retrieve memories, enable us to navigate our surroundings and – if Google’s DeepMind is to be believed – may even play a critical role in imagining what will happen in the future. Bettio et al highlight the roles of education, intelligence and mental stimulation in helping to build cognitive reserve and resilience, but a recent study by Tucker and colleagues, published earlier this year (2017) in the journal Preventative Medicine, suggests that regular physical exercise could be key.

    The Tucker study involved taking measurements from 5,823 randomly selected people and logging their physical activity levels. They showed that the telomeres – a string of DNA bases positioned at the end of each chromosome, in this study the chromosomes of their white blood cells – were significantly longer in those who exercise regularly. Not only that, the more active the people were, the longer their telomeres. The significance of this is that telomere shortening has long been associated with gradual deterioriation of our organs and tissues during aging. The exciting conclusion here is that keeping physically activity and taking more strenuous exercise on a regular basis actually seems to preserve telomere length. They even managed to put a figure on it. The High Activity group had reduced their biological aging by 9 years compared to the Sedentary group and by 8.8 years compared to the Low Activity group.

    These aren’t my parents (in case you wondered)

    As much as a healthy diet and reductions in air pollution probably helped in general, it seems that the key difference in the rate at which my parents aged in comparison to my grandparents is largely due to the telomere-preserving influence of their active lifestyle (regular walks and dancing classes) and biweekly visits to the gym (to do body pump and yoga). So, if you want to help your middle-aged people age more gracefully, then it’s time to get them down to the gym or out on long walks, on a regular basis.

    In addition to these monthly blogs, I regularly post brain news on my twitter account (@drjacklewis), do a fortnightly science podcast (Geek Chic’s Weird Science) and present a TV series called Secrets of the Brain on Insight TV (Sky channel 564).

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