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 28^th 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).