Now is the perfect moment in history for snake-oil sellers to make a fortune. There is a shadowy plague out there, and it has everyone even more worried than usual about their health. It is also the first time in history, as far as I’m aware, that there is apparently a real (if very small and highly debatable) health benefit to smoking- it seems to make it less likely for the virus to propagate inside your tissues. But does that mean you should take up smoking?

If not, why not?

If there was a pill you could take that had a 10% chance of killing you right now, but if you survive you are immune to all diseases, would you take it? I’m guessing probably not.

In other words, how do you assess the relative merits of different health strategies, and come to a reasonable decision about what advice to follow, and what to ignore? I’ll take three possible anti-corona prophylactics and compare them, so you can see how I think about this issue. These are smoking, vitamin D consumption, and Guy’s Quite Amazing Corona Kure (QUACK™ for short), which is a pill I am selling for only a thousand dollars each. One 30-day treatment (three pills a day) guarantees you’ll never catch corona. Really!

Here’s my approach.

1. Evaluate your sources.

2. Measure the downside.

3. Evaluate the upside.

Step One: evaluate the sources of your information. Top tip: if the person telling you something is good for you is also selling you that thing, they may be right, but they are an impossibly compromised source. If you are a trained scientist you don’t need my advice on this, but if you’re not, you should definitely read Ben Goldacre’s Bad Science (affiliate link). It’s a critically useful book to help you evaluate sources, and critique scientific studies.

I’ll rank the common sources in ascending order of reliability.

• Politicians generally (and especially right now in both the UK and the USA) are so full of shit you could fertilize your roses with them. Treat everything they say with the greatest suspicion unless it exactly follows the advice given by the people at the end of this list.
• People selling the treatment. They have a vested interest in you buying, so may or may not be telling the truth. Their sales page is usually tricked out with snazzy videos and testimonials. Testimonials are problematic. Yes, I use them in my course sales pages, because they are true and they work. But really, if the seller is in control of the testimonials, then any negatives will be filtered out. Reviews on Amazon work because you know that people can post negative reviews, so a good average star rating can be trusted. So, be very wary of reviews when buying anything from a source where the seller is in control of the sales page. If there are more than 20 reviews, and they are all entirely positive, there’s probably something going on to filter out the negatives.
• Newspapers and general magazines are also notorious for taking studies out of context and publishing misleading reviews under frankly fraudulent headlines, so the publishing source is crucial.    
• Science magazines such as New Scientist or Nature are much better. 
• Probably the best sources for advice are the national-level health services (such as our NHS), the Centers for Disease Control and Prevention, and the World Health Organisation. Yes, any of these places can and do sometimes give out recommendations that later prove to be wrong- but in general their advice gets better and better over time, and you can be as sure as is humanly possible that the advice is coming from a disinterested view of the available evidence.

The Halo Effect is a well-documented cognitive bias that leads us to make mistakes by letting positive feelings you may have towards the messenger influencing how much you trust their message. Watch out for it when considering the reliability of your sources.

I’ll link to some reputable sources for the effects of smoking and of vitamin D below. Sadly I couldn’t find a single scientific study done on QUACK™, which is a damn shame because it would blow all the other options out of the water!

Step Two: measure the down-side. 

Notice I said ‘measure’, not ‘evaluate’. Because anything that doesn’t have a measurable downside has not been studied sufficiently to be safe. If you can’t measure the downside, at least in part, don’t do it. You can start with time and money, but there should also be some solid data on probability of developing side effects.

Smoking is very expensive, and is known to have all sorts of health disadvantages, such as early death from cancer, heart disease, and stroke. It also reduces athletic performance, smells disgusting, and poisons everyone around you, not just yourself. Its downside is measurable in several ways, and in every dimension, that downside is huge.

Vitamin D is acquired by exposure to sunlight, and through dietary measures. The downsides are harder to establish- if you live in Australia, then the sunlight could also give you skin cancer, and if you live in Finland, there’s rarely enough sun to produce any vitamin D. But you can get it in pill form, at very low cost, and you can get it from eating fresh vegetables, at higher cost but with considerable additional health benefits. So the primary downside of vitamin D seems to be you have to get outside, and eat healthily. Hmmm…

Literally every treatment you can buy from a reputable source (such as your local pharmacy) has a list of side-effects that comes with it. There is no such thing as a treatment that has no downsides. Except QUACK™, of course. I totally promise that QUACK™ has no downsides at all. The price is very fair and reasonable, and it’s guaranteed to work. If you die of Corona, you get your money back!! Honest!

Step Three: evaluate the upside.

As far as I can tell, if you smoke, you may be less likely to develop the disease, but if you do develop it, you’re more likely to die. This article from the New Scientist is a good starting point.

Vitamin D has a host of well-established and incontrovertible, even measurable, upsides. Without it you die. Nobody ever died of not smoking.* Vitamin D is required for a host of physiological processes, not least bone development, immune function, and yes, it seems that patients with higher levels of vitamin D in their blood (but within the safe range) do have better survival rates if they develop the disease. 

Here are the National Health Service guidelines on vitamin D.

QUACK™ is the only preventative treatment for Corona virus that has a 100% success rate, and is guaranteed to work. I’ve been taking it for the recommended 30 days and I don’t have Corona. See! 

So, I’m taking orders for QUACK™ now…. A mere $90,000 guarantees your Corona-free-future!™

But seriously, you can use this process for evaluating any health advice. Breathing exercises, for example. Should you do them? I’d say so, but then I’m selling a breathing training course in my Solo Training package so don’t listen to me. But the down-sides seem relatively small: you wasted some time (if you did the free stuff), and some time and not much money (if you paid for training, and besides, you can get your money back just by asking for it). Nobody ever died of breathing. The potential upside is better physical and mental health, so it’s probably worth trying it out. Supplements are a different kettle of fish- how do you know what’s really in them, and what the effects will really be? Evaluate your sources. Measure the downside. Evaluate the upside. 

I hope this helps. 

So what am I actually doing to stop myself catching the plague?

1) I’m staying the fuck home.

2) If I do go out, I wear a mask. That is more likely to keep others safe than it is to stop me from getting it, but if everyone wore a mask, infection rates would drop. I’m also careful about social distancing.

3) I wash my hands a lot more than I used to.

4) I’m careful about touching my face if I’m out. The mask is a very helpful reminder for that.

5) I’m keeping up my vitamin D levels with sun exposure, and healthy eating.

6) I’m maintaining my basic fitness with breathing exercises, calisthenics, and stretching.

7) I’m taking cold showers regularly (but not if I’m feeling even a bit under the weather).

8) I’m maintaining social contacts as much as possible- there are several friends I’m “seeing” much more often than I used to. This is good for mental health which in turn is good for immune response, as well as giving me the spoons to keep up with steps 1-7.

9) I’m paying attention to the quality of my sleep. Sleep is massively important for every imaginable health metric. I’ll write up a full post about it soon, but in the meantime you can check pages 245-248 of The Theory and Practice of Historical Martial Arts for basic guidelines and suggestions, or read Why We Sleep by Matthew Walker (affiliate link).

10) I’m also using my parenting power to keep my wife and kids as safe as possible, so we won’t bring the virus home.

None of this guarantees anything, but there are no guarantees in life anyway. What it does do is reduce the probability of my catching the virus, and if I am exposed to it, it reduces the likelihood of my spreading it, and increases the likelihood of my surviving it. That’s enough.

*Literally every categorical statement ever made on the topic of health probably has at least one exception if you can find it. I look forward to a deluge of emails giving examples of people whose lives have been saved by smoking. Somehow, somewhere. But you get my point, I think.