• Three Brain Hacks

    Earlier this month I gave a talk in an achingly cool studio space in Wapping; a short distance east along the Thames from Tower Bridge. This future-proofing healthcare event seemed to be a great success and I even got meet a hero of mine. I’m happy to report that not only is Henry Marsh a well-regarded neurosurgeon and fantastic author (whose book Do No Harm I reviewed here back in 2015), but he is also a brilliant speaker!

    My brief was to open the event with a quick overview of what the brain is, how its building blocks are arranged to accomplish all the marvelous things our brains can do and then offer a handful of tips and tricks that everyone can use to get their brains firing on all cylinders. When I give these talks there is always hard science behind whatever I share with the audience. It occurred to me that flashing up the relevant references on screen is probably not sufficient if people wanted to go back to the original science papers at a later date. In this month’s blog I thought I’d provide a few links to research articles summarising some of the research that motivates me to recommend three brain hacks to help people keep their grey and white matter in tip-top condition.

    SLEEP

    Many people consider it a nuisance to spend 1/3 of life unconscious. In our increasingly busy lives, spare time tends to get squeezed mercilessly and the time we spend sound asleep in bed usually suffers as a result. This is a travesty because it is when we are asleep that the brain does all its running repairs and maintenance work. It is when temporary memories reverberating around the brains neural highways are re-visited, the superfluous ones deleted and more important ones consolidated into long term memory by the laying down of proteins. According to a brilliant study published in the journal Science the metabolic waste materials that build up in the brain over the course of the day are also removed at a much faster rate when we are asleep compared to when we are awake.

    If these metabolic waste materials are allowed to accumulate in brain tissue it can have a negative impact on brain function and can potentially build up to levels that are neurotoxic, hence prolonged sleep deprivation being deadly for all animals. So a huge part of the reason it’s vitally important that we all try to get at least 7 and ideally 8 hours of sleep each night is to give the brain an opportunity to banish as much of these potentially toxic materials from the brain as possible. While the 2013 study was in mice, a paper published this month in the Proceedings of the National Academy of Science also demonstrated that sleep deprivation has a similar impact on the clearance of toxic substances from the human brain too.

    I’ll not go into further detail here as next month’s blog will be a review of Matt Walker’s book Why We Sleep, but I’ll conclude with one more sleep-related tip. It is perfectly normal to feel drowsy in the mid-afternoon. Acting on the urge to have a 15-20 min nap is not just restorative, enabling you to continue your daily activities with greater efficiency but, perhaps even more importantly, it also vastly improves memory retention and creative problem solving. Personally, I take a nap most days. In fact, I’m feeling the urge right now, so I’ll complete this blog once I’ve taken 40 winks (1 nap-wink = 30s ;-)…

    … that’s better! (I genuinely did). Not only do I practice what I preach but I regularly urge businesses to encourage their staff to take an afternoon nap every single time I speak at a business conference. On many levels it is flagrant false economy to allow the myth  that napping is tantamount to laziness to be perpetuated. It simply couldn’t be further from the truth.

    HYDRATION

    Every single morning we wake up dehydrated. That’s because we have to keep breathing 24/7 to stay alive. This is the only way we can keep our oxygen levels topped up (to maximise the release of energy from glucose to keep our vital biological processes ticking over) and to eliminate the carbon dioxide that is a key waste material of this process, which would otherwise increase the acidity of the blood with potentially catastrophic consequences. To keep these gases moving in and out of the bloodstream, the inner surface of the lungs must be kept moist, which means that every time you exhale you are blowing away a little bit of water vapour.

    Assuming we stay asleep for 7-8 hours, we will always wake up a little bit dehydrated, which knocks all sorts of biological mechanisms out of kilter. From the brain’s perspective the most important impact of this dehydration is that it has a negative impact on neural transmission – the capacity for each of your 86 billion neurons to efficiently send electrical messages along their wire-like axons and thereby influence other brain cells. People usually wake up a little bit grumpy because the first thing to go awry when people are dehydrated is mood. The cognitive impairment associated with dehydration also explains why you’re likely to find yourself prone to getting mixed up in the process of executing straightforward tasks. Accidentally putting coffee in the saucepan with the porridge instead of the cafetiere where it belongs is a personal favourite, as is the struggle to find everything needed for the day ahead in the daily rush to get out the door on time.

    Do yourself a favour: make drinking a glass of water (laying in wait on your bedside table) the first thing you do after switching off the alarm to help you minimise the amount of time you spend lacking a sense of humour and unable to perform the simplest of tasks effectively each morning due to a dehydrated brain. Having started the day well, monitor your mood and when you feel irritable, before you try and blame others for being so annoying, think to yourself – when was the last time I drank water? (NB not coffee, fizzy drinks or juice, but just plain, old-fashioned, H2O).

    COFFEE

    There is pretty good evidence to suggest that people who drink a moderate amount of coffee each day have a lower risk of Alzheimer’s disease and also (in men at least) Parkinson’s disease. We still don’t know what exactly it is about the magic bean that confers these neuroprotective effects – the most popular hypothesis is that the benefits arise as a result of all the antioxidants contained in the coffee bean helping to soak up all the free radicals that would otherwise interfere with our DNA.

    Despite these benefits, there are drawbacks to a voracious appetite for coffee. One broadly overlooked peril of the coffee habit is that caffeine has a very long half-life. It takes 6 whole hours to reduce the concentration of caffeine in the bloodstream by half (NB this takes much longer if you’re pregnant or on the contraceptive pill, but less time if you’re a smoker). This means that if you have the equivalent of 4 cups of coffee’s worth of caffeine in your bloodstream at midday, then it will take until 6pm before this has been reduced to 2 cups-worth and 6 hours after that – at midnight – this will finally have been halved again: down to 1 cup of coffee’s-worth of caffeine. Clearly anyone who is in the habit of drinking coffee throughout the afternoon is going to have so much stimulant swimming around their system come night time that it will inevitably interfere with their sleep. We’ve already covered the reason’s why this is bad news for brain health.

    The upshot is this: to avail yourself of the neuroprotective benefits of coffee, without suffering negative impacts on sleep in terms of onset, duration and/or quality, then get all your coffee drinking out of the way in the morning and if you absolutely must take caffeine onboard in the afternoon, then at the very least try to switch to green tea instead (15% of the caffeine in a cup of coffee). The next time a waiter or waitress offers you an after-dinner coffee, feel free to inform them that they are effectively tempting all their customers to play roulette with the health of their brain.

    NEXT UP

    I’m giving another talk at the end of this month – at 1pm on Sat 28th April – at the Leeds International Festival on the topic of how technology impacts our brains. If this is of interest, then tickets are available here – it’s free!

    In addition to these monthly brain blogs, I regularly tweet about brain-related research that hits the lay press (@drjacklewis), I do a fortnightly podcast about the more unusual scientific breakthroughs (Geek Chic’s Weird Science) and in July 2018 my new book Science of Sin will hit the shelves in the UK (11th Sept in the USA).

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  • The Future of Deep Brain Stimulation

    Ed Boyden is a professor at the Massachusett’s Institute of Technology who leads the Synthetic Neurobiology group. He’s credited with important contributions towards the revolutionary field of optogenetics. Essentially, it involves a bunch of molecular tools that make specific groups of neurons switch-on-and-offable simply by shining a light on them. This incredible innovation has given neuroscientists unprecedented level of precision in controlling the activity of different types of neuron in experiments trying to unpick the brain’s mind-bogglingly complex circuitry.

    It seems that he and his research team may well have done it again. They have developed another potentially incredibly powerful innovation that could fundamentally change how we approach Deep Brain Stimulation (DBS). This new approach is called Temporal Interference Stimulation (TIS) and the breakthrough it offers is enabling deep brain structures to stimulated without having to cut through the skull and actually insert electrodes into the brain.

    The DBS approaches currently used in humans involve passing electrodes through holes in the skull all the way down to deep brain areas in order to deliver pulses of electrical stimulation at the desired location. This has become a relatively routine medical intervention that fundamentally improves quality of life for thousands of people suffering from a range of brain illnesses all over the world. It has proven effective in a variety of chronically-debilitating diseases including Parkinson’s Disease, Major Depression and Obsessive Compulsive Disorder helping to circumvent common problems whereby patients either don’t get any improvement from their medications, or do at first but then the drugs stop working after a period of time.

    DBS therapy is most striking in people with Parkinson’s patients. Gradual death of the dopamine neurons that play an important role in initiating voluntary movements is the root cause of Parkinson’s disease. Dopamine-boosting agents often help with their movement difficulties but the benefits do not usually last forever. The invention of NICE-approved DBS therapy has been a lifesaver for many thousands of people. By applying an electrical current to either the thalamus, globus pallidus or subthalamic nuclei, limb movements can be controlled as normal. Their distinctive seemingly hesitant, shuffling walking style can be replaced with a normal, confident striding gait at the flick of a switch.

    The surgically-implanted electrodes often yield remarkable improvements in their symptoms, but having to cut holes in people’s skulls and physically implant wires in their brains is fraught with risks and potential complications. TIS, at some point in the future, could offer the same benefits but without the need to put any man-made objects inside the brain.

    We’ve had technologies that are capable of influencing brain activity from the skull surface for many years. Both Transcranial Direct Current Stimulation (tcDCS), which sends electrical currents across the skull, and Transcranial Magnetic Stimulation (TMS), which produces transient magnetic fields that extend across the skull, are both able to influence brain activity without the need for invasive surgery. But tcDCS and TMS are unable to influence areas deep inside the brain with any precision, they can only modulate brain activity at the surface. With TIS, all that it set to change as the technology progresses from experiments with mice, through larger and larger mammals, until it is eventually (hopefully) proven to be safe and effective in humans.

    As with all brilliant scientific solutions, TIS is elegant in its simplicity. A high frequency electrical current has no effect on brain tissue. At lower frequencies electrical currents can disrupt the usual flow of information in whatever brain tissue it is passed through. Here’s the clever bit. By applying two different sources of high frequency electrical current, at carefully separated positions on the scalp surface, where the two currents overlap sufficiently to cause interference in a way that reduces the frequency of the combined electrical signal it’s possible to alter how the brain tissue functions. Every other region that the electric currents pass through on the way down to the target location is unaffected – only where the beams cross.

    The team’s recent paper, published in the journal Cell (free to download!), describes how this technique was used to selectively stimulate the mouse hippocampus, deep inside the temporal lobes, from the top of the skull. While reaching down to the human basal ganglia from the skull surface is a much greater challenge – penetrating to a much greater depth, across a much thicker skull – this proof of principle makes the dream of deep brain stimulation without surgery seem a realistic prospect in the not too distant future.

    In addition to these monthly blogs, you can follow me on Twitter (@drjacklewis) where I post articles on breakthroughs in brain science and related topics. I also do a fortnightly science podcast with the lovely Lliana Bird. I also present a TV series called Secrets of the Brain on Insight TV. You can watch series 1 on Sky channel 564 (It’s on most nights!), or you can stream it here. Series 2 is out in Autumn 2017…

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  • Caffeine Nation – good or bad for you?

    Coffee-BeansWhat Does Caffeine Do To Your Brain?

     As a neuroscientist who spends much of his working life giving brain talks at events all around the country (at schools, conferences and science festivals) I’ve noticed that one theme catches public imagination over and over again: How does caffeine work? What does it do to my brain? How long does it stay in my system? Is it really that bad for me? This is one reason why it became one of the key topics in the “Smart” Drugs chapter of my book: Sort Your Brain Out. In this blog I’ll cover some of the most regularly asked questions.

     

    How long caffeine takes to leave your system?

    It depends what other drugs you’re on. If you’re on the contraceptive pill it can take up to twice as long for your liver to remove caffeine from your system. So people “on the pill” can find themselves particularly sensitive to its effects because consecutive doses stack up and are not cleared out as swiftly as in everyone else. But if you’re a smoker it is the other way around. Caffeine is removed from your system at double the speed of a non-smoker.
    If you’re neither a smoker nor on the contraceptive pill the concentration of caffeine in your bloodstream is halved every 5-6 hours, but it really does depend on the individual as this “half-life” varies greatly from person-to-person.

     

    Is it beneficial to have caffeine before a meeting / presentation / to improve concentration?

    coffee-loverCaffeine blocks the receptors of an inhibitory neurotransmitter called adenosine, which under normal circumstances reduces overall activity across the brain. By blocking these receptors and removing the dampening influence on brain activity, caffeine increases activity across brain pathways involved in alertness, focusing attention and initiating body movements. This why people dosed up on caffeine can get quite jittery.
    Whether or not caffeine is beneficial for you in a meeting / presentation or to improve concentration whilst working depends on how much you’ve already had. There’s a sweet spot where you will feel more alert and switched on at moderate levels, but beyond that you can become so wound up that it has effects that are deleterious to performance (see description of caffeinism below).
    However the increase in feelings of alertness and ability to focus attention only gets regular coffee drinkers up to levels enjoyed by non-caffeine drinkers everyday. This is because once you’re a caffeine addict the brain tends to increase the numbers of adenosine receptors to compensate for the fact that there’s loads of caffeine swimming around in your brain on a daily basis. This means that your average coffee drinker has more inhibitory receptors in their brain dampening activity levels to a greater degree – so they will feel more sluggish whenever they don’t have caffeine in their system.

     

    Is caffeine good or bad for you in the long run?

    There seem to be some long-term benefits to drinking caffeine even if the short-term benefits don’t amount to a whole hill of (coffee) beans. It has been observed that regular drinkers of moderate amounts of caffeine (3 cups / day) have a lower incidence of Parkinson’s, Alzheimer’s, liver and heart diseases. This may be due to the increased numbers of inhibitory receptors triggered by ever-present levels of caffeine dampening activity levels in body and brain. The decreased activity levels across the brain caused by the larger numbers of inhibitory receptors in the caffeine drinkers’ brains may relieve the pressure on dopamine neurons that are compromised in Parkinson’s disease and the acetyl choline neurons that get clogged up with various proteins in Alzheimer’s disease. In other words caffeine seems to slow down the process of cell death so that symptoms of these diseases kick in several years later than in your average non-caffeine drinker. At the moment this mechanism is purely speculative. The jury’s still out on the precise mechanism that might account for these observations, but the evidence supporting the concept of moderate amounts of caffeine having a neuroprotective influence on the brain is steadily increasing.

     

     

    Is it important to control and monitor your caffeine intake?

    CoffeeOnDripA dose of 10g is deadly – 100 cups and a human may well find themselves popping their clogs as a typical cup of brewed coffee contains 100mg of caffeine. (NB you may notice that in the above video from the lovely people at ASAPscience they say 1 cup of coffee has 150mg – presumably they brew it stronger over in Canada 🙂 For the non-coffee drinkers out there here are some average caffeine contents of some other popular drinks. There are 80mg in a can of Red Bull, 75mg in a cup of instant coffee, 50mg in a cup of tea, 30mg in a can of Coca Cola.

    Very high but not deadly doses can lead to a quite severe psychiatric condition known as caffeinism: “which is characterised by restlessness, agitation, excitement, rambling thought and speech, and insomnia.” (Winston et al, 2005). It is important to control and monitor caffeine intake because too much can interfere with appetite, make people anxious or depressed, not to mention the fact that anything that interferes with sleep will have a deleterious effect on the brain. Everyone’s sensitivity to caffeine is slightly different, but if you have trouble sleeping then you’d be well advised to avoid caffeine at least 5-6 hours before bedtime – for your brain’s sake.

    3 cups of coffee per day is considered a “moderate dose” for most people. Get these in early enough to avoid any potential for them to interfere with sleep and you should get the apparent long-term brain benefits without the negative consequences associated with excessive consumption (DISCLAIMER: this should not be interpreted as medical advice – it is just the science-based opinion of the author who has a Ph.D. in neurobiology i.e. not a medical degree!).

     

    I don’t like tea or coffee, are there any other sources of caffeine?

    head in coffee beansCaffeine is also found in kola nut (one of the original ingredients of coca cola) and guarana – a wonder berry from the Brazilian rainforest; it’s also found in low quantities in chocolate. Caffeine is also included as a stimulant in many cold and flu remedies – so beware what you reach for when you wake up in the middle of the night with a bunged up nose!

    By the way: if you study the picture on the left very carefully you’ll find a face amongst the coffee beans – can you find it?

    Keep looking… he’s definitely there and you’ll kick yourself for doubting me when you find him!!

    If you liked this you’ll love my daily brain tweets so please follow me on Twitter by clicking here.

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