• 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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  • A Book Pairing for Summer 2017

    Certain restaurants like to suggest specific wines that go well with particular dishes. The crisp, citrusy, Sauvignon Blanc to go with a dish of lemon sole, or the full bodied, smokey Malbec to go with a sirloin steak. The flavours of the wine and the dish are often said to mutually reinforce each other, such that the combination is greater than the sum of its parts. Passing through an airport bookshop earlier this month I made a lucky spontaneous decision that demonstrated a similar effect is possible in the literary world. So I thought I’d share my discovery with you: I picked up two books, one fiction, one non-fiction, and they complemented each other perfectly. I would wholeheartedly recommend the following pairing.

    Over the past twelve months or so I’ve seen lots of people wielding a copy of Yuval Noah Harari’s SAPIENS – A Brief History of Humankind in planes, trains and automobiles. When everybody seems to be reading a certain book it always piques my curiosity. Either the marketing campaign was particularly effective or, more likely, each person who chose to buy it had been recommended it as a good read by a handful of people. As regular readers of this blog will know: I’m a sucker for Wisdom of the Crowd. And it did not let me down on this occasion because SAPIENS is an absolute cracker.

    A huge volume of well-packaged, condensed, easy-to-assimilate information that touches on the major milestones in our species’ prehistory including our encounters with other, now extinct, human species, the agricultural and industrial revolutions, and a wide variety of human empires that rose and fell through the ages is presented with great speed, style and finesse. The most gob-smacking revelation for me, overall, was mention of the genetic evidence suggesting that a fair chunk of European human DNA is of Neanderthal origin and a sizeable portion of Asian human DNA originated in the Homo erectus species. We’d covered a science story on the fact that Neanderthal’s were to thank for the keratin in our hair and nails on the Geek Chic Weird Science podcast, but I’d presumed that this was the case for all Homo sapiens, not just the European ones. The concept that the human species with which our ancestors had sexual dalliances differed according to whether the Homo sapiens in question happened to reside to the east or the west of the Eurasian land mass came at me like a bolt from the blue.

    Jean M Auel’s Clan of the Cave Bear is the first book in a series of works of fiction describing an orphaned Homo sapiens girl being adopted into a Neanderthal tribe. Access to evidence regarding how Neanderthals behaved, what they believed and the extent of their knowledge is inevitably scant given how long ago they were wiped off the face of the planet. But Auel’s account of their superstitions, social organisation and rigid thought processes seemed entirely plausible. I’ve always been a great fan of Bernard Cornwell’s books. I love his approach of sticking faithfully to the historical record regarding the Saxon and Viking invasions of Britain wherever it is available, but filling in the gaps with reasonable fictions that are entirely compatible with what is known from those times. I got the distinct feeling that Jean Auel takes a similar approach. Even when the storyline became slightly fantastical as the tribal witch doctor communes with the ancestral spirits to seek advice on the best course of action, the brews concocted by their medicine woman were certainly based in fact. And speculations regarding differences in the cognitive abilities of Homo sapiens and Neanderthal’s also seemed reasonable given what we can glean from the skulls in the archaeological record.

    Frustratingly, the further back into the history of our species we peer, the greater the uncertainty regarding the actual facts. I personally found the pairing of the facts presented in Sapiens A Brief History of Humankind with the fictional accounts of the nature of interactions between Neanderthals and Homo sapiens in The Clan of the Cave Bear to be an absolutely delicious antidote to this problem. And I hope you do too!

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