One of the advantages of being a TV presenter, particularly if you’re someone who likes to self-experiment, is that you find out lots of unexpected things about yourself.
Though not all of this is good news. Thirteen years ago I discovered through a random blood test that I had type 2 diabetes, and went on a journey (with camera crew in tow) to see if I could cure myself.
More recently, I’ve been making a series about sleep, and discovered why I have insomnia — and that I have another life-shortening condition, obstructive sleep apnea (OSA).
OSA is incredibly common, with up to ten million Britons affected. Essentially it means you repeatedly stop breathing while asleep, because your throat and tongue muscles relax, blocking your airway.
Your brain, ever alert, wakes you up just enough so you shift on to your side and start breathing again. This can happen more than 30 times an hour. Those affected tend to make gasping, snorting or choking noises, as they try to get air into their lungs.
Dr Michael Mosley discovered his insomnia is caused by obstructive sleep apnea – a condition where a person repeatedly stops breathing while asleep
Not surprisingly, if you have OSA then despite being asleep for eight hours or more you will probably feel really tired during the day and may suffer from memory lapses. But it can also have a terrible impact on your long-term health. However, less than 15 per cent of Britons who have it know they have it, let alone get any treatment.
While I knew that I was sleeping badly and often felt tired in the day, I thought that was because I would regularly wake up during the night and find it hard to get back to sleep.
Then last year I went to Australia to make a series on sleep: this included taking part in a revolutionary trial being run by Flinders University at its sleep health institute in Adelaide.
The idea was to take 30 people who have struggled with their sleep for years and use cutting-edge technology to diagnose their problems — then see if a tailored sleep programme could help.
We all had to spend a night being observed in a sleep lab – we had electrodes attached to our heads to record our sleep, and were also filmed and observed during the night.
Professor Danny Eckert, an expert on sleep disorders who led the team, told me that my data showed I had moderately severe OSA, and it was particularly bad when I was lying on my back.
This was a nasty shock because, as well as making you feel tired, if you have untreated OSA then that greatly increases your risk of heart disease and stroke.
And it turned out that I was not alone. A third of the volunteers in the trial were found to have OSA, and many, like me, were blissfully unaware of it.
So what are the risk factors for OSA? Most people who have it also smoke, drink (both cause your upper airway muscles to relax), or are significantly overweight and have a large neck — but none of these are true of me.
However, OSA is also more common in older men (tick) and may have a strong genetic component (tick, my dad had it).
As for treating it, while weight loss can be helpful, my BMI is already in the healthy range.
The team knew I wasn’t keen on a CPAP machine (which involves wearing a mask while asleep, which pushes air into your airway to keep it open), so they suggested some alternatives.
First I was fitted with a mandibular advancement device, a type of mouth guard that pushes your jaw forward. This stops your tongue flopping back and blocking your airway.
The second device they recommended was a strap that’s worn around the neck which detects when you’re lying on your back — it then emits a buzzing sound to alert you to shift on to your side.
You could also try cheaper, low-tech approaches, as suggested by the NHS, such as sewing a tennis ball into the back of your pyjamas or buying a bed wedge. But it turned out that my sleep problems weren’t confined to OSA.
All the trial participants had to swallow an electronic pill, which measured our core body temperature. This fluctuates over the course of 24 hours, but is normally lowest around 4am, when you should be at your sleepiest.
But my core body temperature is at its lowest around 1am, three hours earlier than normal.
That could explain why I find it hard to stay awake much beyond 10pm and why, when I wake at 3am, I find it so hard to get back to sleep (my body clock thinks it is dawn and time to wake up).
So the answer for me was expose myself to bright light last thing at night.
As Professor Leon Lack, a psychologist at Flinders explained, this would help shift my body clock later and mean I was less likely to wake up at 3am feeling so bright and alert.
He also recommended I try ‘bedtime restriction therapy’, which in my case involved going to bed at 11pm every night, and getting up at around 5.30am every morning for at least four weeks.
The idea is to teach your brain to associate being in bed with sleep, rather than lying awake. Once you start sleeping better you can gradually increase the time you spend in bed.
It’s tough, at least initially, but is also an effective way of treating long-term insomnia (for more detail about all this see my new book, 4 Weeks To Better Sleep).
All this has made a huge difference to my sleep; I’ve now got my OSA and insomnia under control and as a result I feel full of energy during the day.
Best of all I can take part and enjoy family activities, where previously I might have felt so drained I’d withdraw into myself.
As for the rest of the trial participants, more than 80 per cent experienced life-changing improvements in their sleep.
One said to me: ‘I’m now getting sleep that is so good it should be illegal.’
The results of the trial were so impressive they’re going to be published in a leading sleep journal later in the year.
Humanity has had a long-running battle with nasty microbial infections, but we also owe microbes a lot: without them turning sugar into alcohol there would be no beer or wine.
And it seems we can also thank them for our ability to think.
A study by the Cambridge Institute of Science found that our ability to produce myelin (the insulation around our nerves, which allows messages to rapidly travel to and through our brains) is thanks to a virus that infected a relative of ours tens of millions of years ago. Something to ponder when you get your next cold.
Like many others, I’m increasingly concerned about the growing threat posed by plastic pollution.
It’s not just the plastic bags that scatter the hedges when I go for walks, but microplastics, the tiny particles of the stuff that are literally everywhere and are increasingly seen as a major health risk.
Direct evidence for this came from a study published in the New England Journal of Medicine. Researchers in Italy examined samples of plaque (the fatty deposits that line your blood vessels) from patients who’d recently had surgery to remove it.
Microplastics are tiny particles of plastic that are everywhere and are increasingly being seen as a major health risk
Nearly 60 per cent of the samples contained microplastics — furthermore, the patients with microplastics in their plaque were nearly five times more likely to have a heart attack, a stroke or to die in the 34 months after surgery.
The researchers think the microplastics cause chronic inflammation, which in turn causes heart disease and stroke.
Analysis revealed that most of the particles were made of polyethylene, typically found in food packaging and plastic shopping bags; or polyvinyl chloride (PVC), used in plastic bottles.
There’s not a lot you can do to steer clear of microplastics, though at home my wife Clare and I avoid heating or microwaving anything in a plastic container. We also drink tap water rather than bottled.
You could also boil tap water for a couple of minutes, then filter it when it cools. A study in the journal Environmental Science & Technology Letters found this removed more than 80 per cent of microplastics, particularly if the water is hard.
That’s because boiling releases calcium carbonate (i.e. limescale) from the water, which then traps the microplastics, which you can then filter out.