The body is a complicated thing. Even the most knowledgeable scientists are still frequently baffled by its curious and complex workings. Hence, we still have no cures for autoimmune disease, cancer, dementia etc etc
And despite the billions being pumped into potential longevity medications, there is still nothing as effective as movement for our brains and bodies. For every costly failed longevity drug, another life-enhancing endogenous (in-body) biochemical is discovered.
As the evenings draw in and the temperature drops, the human inclination is to move less. But this would be a big mistake, purely for biochemical reasons. If you’ve been watching the Blue Zones series, you’ll have noticed that very few Blue Zoners watch TV all day (as my grandmother did in her nursing home). Their pace may have slowed but all of them are active. With this movement, comes a level of contentment (which I’ll explain in a minute) that also contributes to their good health. This is the body, brain and mind working like the beautifully oiled machine it was designed to be.
So let me tell you about a couple of the latest astonishing discoveries – if only to urge you up and out. And please do forward this to anyone who might find it useful. We all have periods when we need a little motivation!
First up – the kynurenine pathway. A pathway is really just a term for a chain of molecular interactions that takes place in the body and results in changes to a cell, a gene, or to the formation of new molecules. This one is particularly complicated and is still being untangled by researchers, but for those wanting to fully grasp the biology, there’s an excellent overview here.
What you need to know about kynurenine is this: high levels of it don’t bode well for ageing well. Several studies have found that older people, those who’ve had hip fractures, the frail, as well as the depressed have higher circulating levels of kynurenine. Indeed the more kynurenine in your blood, the greater your chances of dying sooner rather than later. High levels of kynurenine also seem to be associated with low levels of melatonin and serotonin – meaning both poorer sleep and a greater risk of depression.
So what’s going on? No one really knows but it seems that inflammation activates an enzyme which causes our body to start making larger amounts of kynurenine, which in turn results in other damaging molecules being made.
A recent study in the journal, Aging, described excess kynurenine ‘as a significant predictor of frailty.’ Too much of it has also been described as ‘a primary driver of the aging process.’ Researchers think a surfeit of kynurenine might also be a significant predictor of Alzheimer’s, heart disease, Parkinson’s, cancer and even Hepatitis. Tests show that people with all of the above often have very high levels of kynurenine in their blood.
No surprise then that Big Pharma has been trying to produce a kynurenine-blocking drug for the last few years. It hasn’t succeeded. Their more successful attempts have come with an army of side effects.
But all is not over. New research has identified a very simple way of blocking the accumulation of kynurenine (and its toxic by-products) in our blood and tissues: regular, heart-beat-raising movement.
When we move so that our hearts beat a little faster, the kynurenine pathway shifts direction. Think of kynurenine as much like household grease blocking up plugs and sinks. When we exercise, we activate an in-body hoover which sucks up the grease, opening up plugs and sink-holes.
When we don’t move, the kynurenine pathway becomes clogged, blocking up other pathways (like the melatonin and serotonin pathways for example) and causing untold damage. In fact, blockages of kynurenine trigger a cascade effect of metabolites – not only shutting off much-needed pathways (like those producing sleep-fostering melatonin and feel-good serotonin) but blocking receptors, so that our immunity stops functioning properly.
In experiments involving breast cancer patients, resistance training appeared to reduce kynurenine and its associated metabolites, thereby enabling the body’s anti-tumor system to kick into action. The researchers described resistance training (2 sessions a week) as ‘a potent non-pharmacological avenue … in breast cancer patients.’
Very little is known about what we need to do to reduce our kynurenine levels. It appears to be linked to building muscle (so stretching exercises have no effect). And we know that exercising to exhaustion raises levels, so don’t over-do it. Short bursts of more vigorous movement might help, so try speeding up and slowing down as you walk/run/cycle/swim/dance. If you’re hill-walking and stair-climbing your heart will naturally be speeding up and slowing down.
Researchers think exercise works instantaneously, however. So every bout of muscle-working movement (from walking to weight-lifting) will lower your levels of killer kynurenine – instantly. Meaning better immunity and mood – instantly.
And if you caught the recent news about hospital in-patients who walked for upwards of 25 minutes subsequently making much better recoveries, it might be a result of reductions in circulating kynurenine. The message is clear: bed rest isn’t always what we need. Keep moving! And if you missed this particular news story, catch up here.
So that was kynurenine and we’re expecting to learn more about this intriguing pathway as researchers get to grips with its complexities in the years to come.
The newest magic ingredient, however, is Platelet Factor 4 (PF4). This compound appears to keep our brains and memories sharp. And it too is released when we move. Discovered by a team from the University of Queensland Brain Institute, PF4 is a protein secreted by the tiny blood cells that prevent blood clotting (known as platelets). This protein rejuvenates brain cells (neurons) in aging mice, and researchers now think it may be the reason that exercise and movement amplify the production of new neurons in the brain.
“We discovered that PF4, which is released from platelets after exercise, results in regenerative and cognitive improvements when injected into aged mice,” said researcher, Dr Leiter. Of course, Big Pharma is now investigating. And millions of dollars and thousands of hours later, we may – possibly – have a magic pill.
But for now, I think it’s pretty clear. Prepare for an active autumn and winter. We’re fans of outdoor movement – Vitamin D, fresher air, natural light, the therapeutic effects of trees, sea air, wet earth, seeing other people – and so much more.
Make sure your waterproof coat is waterproof. Invest in waterproof trousers and a warm coat if need be. Check your boots/trainers are still waterproof, sturdy and comfy. Find your gloves and hat. Get your thermal layers out of the attic. If you don’t have walking poles, invest in a pair (you’ll go further and faster and you’ll fall less often). Invest in good socks and a bum bag or backpack.
And say hello to PF4… and goodbye to excess kynurenine!
To help inspire you, we’ve got two copies of 52 Ways to Walk and The Age-Well Project to give away (yes, that’s two bundles of two books), one via email at firstname.lastname@example.org and one on Instagram @agewellproject.
Simply email us or leave a comment on our Instagram post letting us know your favorite landscape for autumn and winter walks. Do you like hills, mountains, flatlands, canals, rivers, coastlines, cities, cemeteries, your local park, moorland…? Just a few words to tell us where you’d most like to be walking in the next few months. The competition closes at midnight on 18 October and I’ll have the books mailed out shortly after that.
And in case you’re wondering why I’m interested in your favorite landscape, it’s because I’m writing a new book about the places we choose to walk in and how they affect us. So I’d love to get a rough idea of the best-loved locations… all in confidence, of course.