Research shouldn’t be about competition - it should be about collaboration.

Prior to my studies into sleep, my PhD mentor from Flinders University - Dr Leon Lack - and one of his PhD students at the time - Drew Dawson - flew to the USA to present their findings of what’s called the Phase-Response-Curve (PRC) to light. Meaning, we can change the timing of the circadian rhythm when exposed to light at certain times of the 24-hr day.

Before Drew’s presentation of his results, the pair of Flinders’ researchers were invited to lunch by two Harvard scientists - Dr Charles Czeisler and Dr Richard Kronauer.

It was a pleasant lunch with pleasantries exchanged; Czeisler and Kronauer showing a keen interest with keen questions about Drew’s PRC work.

After the lunch, Drew went and presented his findings. The audience clapped. The Chair asked if there were any questions. Kronauer stood up. And ripped into Drew with a barrage of questions intended to pick apart and minimise his study. In a typical good-cop / bad-cop scenario, Czeisler stands up to provide a small complement to the Aussie researchers, as if to say ….

Nice Try

What motivates scientists to critically analyse another scientist’s work?

Well … nothing. It’s part of the job. The goal of scientists is to serve science. To identify how to improve on one’s own work, and the work of others to get closer to the truth. Getting to the truth then ultimately serves humankind.

But sometimes, there’s a bad smell of other motivations.

In this case, the Harvard Scientists were also working on a study to understand the PRC to light - spending what is estimated to be millions of dollars creating a light room to perform their testing. A room that even had lights in the floor.

Drew simply took one of his parents’ spotlights from their tennis court and used it in the sleep lab. It was such a powerful light source, it melted some of the equipment in the room. But this little Aussie innovation got us all closer to the science - to understanding the PRC to light.

It seems that Drew and Leon got there first. And Harvard didn’t like it …

Dr Martin Moore-Ede

Drew and Leon still continue to work, as does Charles ‘Chuck’ Czeisler. Unfortunately, Richard Kronauer has since passed. But could I propose to you that the ex-Harvard vs ex-Flinders debate has not?

Cziesler is a giant in the sleep, light and circadian rhythm world. His mentor was Dr Martin Moore-Ede - a giant in his own right, having discovered the human body clock. These days, he’s fondly known as ‘The Light Doctor’.

Without naming names - ie, my name - Dr Moore-Ede came out with a new substack article that put forth arguments against my own - specifically, my argument that the blue-enriched light from screens has a minimal effect on the time taken to fall asleep (check out Table 1 from our review to see the data from 11 studies that support this contention).

To be fair, here is Dr Moore-Ede’s proposal, verbatim:

I find his 2nd sentence odd, as sleep onset and sleep offset is an indicator of circadian timing, and there’s research showing later circadian is linked with worse health.

But again, to be fair, Dr Moore-Ede’s broad argument is that blue artificial light at night is harmful, which I believe there is some partial truth to. But this singular notion then leads to a certain solution …

Blue-Light Blocking Glasses.

Sound familiar?

Last week’s newsletter linked to a interview I took part in, conducted by investigative journalist - Scott Carney - which provided various angles as to why it is odd that Dr Andrew Huberman is helping to sell BB glasses.

But more on that later - because before I go on the offensive, I need to react (be defensive).

Dr Moore-Ede provides 3 reasons which may be intended to plant the seed of doubt. That is, begin to question the credibility of the scientific evidence our team has presented that shows it isn’t difficult to fall asleep after being exposed to a blue-enriched screen before bed.

Here’s the 3 reasons:

1. Sleep homeostatic pressure (ie, the longer you’re awake, the quicker you fall asleep)

2. Stimulants (ie, caffeine makes you more alert; alcohol makes you more sleepy)

3. People get engaged in activities and stay awake past their usual bedtime.

The short story is that I find these to be weak arguments. Indeed, for a scientist of Dr Moore-Ede’s stature, they’re odd. Here’s why …

The majority of studies we present in Table 1 are laboratory studies that controlled for these 3 influences. In our review, we purposely excluded one study by Higuchi and coworkers (2005) because they did not control for number 1 - sleep pressure. In the Higuchi study, they exposed their subjects to a bright screen hours after their usual bedtime and then got them to fall asleep - so they stayed up much later. As such, the mean time taken to fall asleep was 2 minutes.

The lab studies we included controlled for when subjects went to bed, by scheduling it around their usual bedtime - thus controlling for both influences (1) and (3). These lab studies also controlled for caffeine and alcohol. I know this because we ran one of these studies - the first one - and so I’ve been keeping my eye on the subsequent studies being published.

The other studies were ones done in the home, where controlling for these 3 influences are much harder. But get this, the studies performed at home showed a strikingly similar result to those in the lab.

Put together, the data from these 11 studies are more powerful than any single study; more powerful than any single sleep scientist - regardless of where you trained.

So that was the Defensive.

Now for the Offensive - where I’ll argue that BB glasses …

Are Not Needed - By The Public

Dr Martin Moore-Ede summarised his substack article with a post on LinkedIn this week, which could be categorised into two parts - critiquing the science debunking the myth of blue-enriched light on ‘sleep onset’ with some odd arguments, and then providing a host of reasons why blue-enriched artificial light at night is harmful.

Some people may call this ‘fear-mongering’, or a ‘fear campaign’ motivated to lure people towards a solution. But I want you to consider a more neutral stance, which is that this is an ‘alarmist approach’ - whereby a scientist lists bad things that happen - in this case, if you don’t sleep well or if your circadian rhythm is ‘disrupted’.

I have had periods of being an alarmist, which is to say I’ve been on a rollercoaster of ups and downs, where the ups are me exclaiming the harms of poor sleep. But such outcries need to be mindful of people who have poor sleep - as such alarms only worsen their quality of life. The stories and worries I hear when sitting across the room from a client has helped me to temper such fearful messages.

I now prefer to exclaim ‘Sleep is important’ or ‘Circadian rhythms matter’.

So let’s now look at one of these fearful messages - before we turn our attention to Dr Martin Moore-Ede’s proposed solution.

I’ll paraphrase - “Blue-enriched artificial light at night is carcinogenic.”

• First, it is very easy to find peer-reviewed papers in Google Scholar that support the above contention.

• Petri dish studies shows cells of our body are damaged by blue light. But also understand many things can kill cells in a petri dish. And importantly, that the most blue light you’ll get exposed to is naturally from the sun.

• Animal studies are slightly better, but not all of their findings translate well to humans.

• Therefore, human studies are the best representation of how blue light at night may be harmful to humans.

• And there’s no prizes for guessing which humans suffers the worst health outcomes - night shift workers.

• There’s been A LOT of studies that have come out recently to demonstrate that greater exposure to light at night results in very bad health outcomes. Interestingly, some of these great studies have been published by a team from Flinders Uni - and Dr Martin Moore-Ede has agreed with their findings.

For instance, this study of over 80,000 people shows a greater risk of dying the more someone is exposed to artificial light at night (ALAN). It is an extremely well conducted study, and the findings are very clear. Get exposed to more ALAN and your chances of dying - primarily of Cardiometabolic Diseases - increases.

So here’s a little exercise for you if you wish to improve your Sleep IQ … search their study for the word ‘cancer’. How many times does it appear? If you wanna go one step further like I did, download their supplementary analyses and data, and again, search for the word ‘cancer’.

Now this is not to say that if you search Google Scholar for the link between cancer and ALAN that you will not find papers linking the two. You will.

But will you also find this meta-analysis?

The Solution?

I’ve had to think hard about when BB glasses would be needed - because in the interests of declaring conflicts of interests - this week I signed an Agreement with a London-based wellness company, where I will receive a commission from sales of products I endorse.

But I couldn’t think of a situation where BB glasses would be a solution to society’s lighting issues. Here’s some of those situations:

Daytime Use: Dr Moore-Ede and myself agree that you shouldn’t wear BB glasses during the day. Blue light has a role to play in our health during the day. Just be wary of prolonged exposure.

Evening Use - Part 1: After sunset, there’s two lighting issues: (1) our house lights, and (2) screens. I believe people can dim their lights. It’s more cost effective, and it uses less energy. Dr Moore-Ede argues there are instances when people need to do things under bright house lights (eg, doing their taxes) - but let’s give him the benefit of the doubt for that very odd suggestion. I thought taxes were done once a year, and these days on a computer screen? Anyways, I’m not convinced that there’s enough situations where people need to wear BB glasses in the evening because they have to do some sort of task that requires house lights. Which leads to what the majority of people do in the hour or so before ‘bed’ …

Evening Use - Part 2: Screens. I don’t understand why people who sell BB glasses suggest they can be used when viewing a screen in the evening. Screens have to be full brightness to have any suppressive effect on melatonin - and that occurs when people are in a lab and have spent 1 hour in darkness. People don’t do that shit in the real world. So just dim your screen, or use a blue-light suppressing filter - and enjoy your time at the end of the day. But just be mindful of the time and keep a consistent bedtime.

Overnight Use - OK, so what if you cannot control your lighting environment? The best example for this are shift workers. Well, the argument for BB glasses in these situations is to block blue light as it suppresses melatonin, and if melatonin is suppressed then it can lead to a number of health issues, like cancer. Well, here’s the thing. Our melatonin levels are suppressed when we sit up, stand up, and move around. So regardless of whether you’re working under blue-enriched artificial light, complete darkness, or changed all your light fittings to red light bulbs, if you’re up and about then you’re suppressing melatonin.

Any (true) market research that was based on science would discover there aren’t that many people that need these - in other words, it’s a small market. Regardless, you won’t see me endorsing (relatively expensive) BB glasses.

For an example of what I will eventually endorse, they’re a device that became commercially available in 2012, and were based on research published a decade earlier.

They have something to do with light, and they have evidence for their efficacy. My team has been one of those research groups that have reported on their therapeutic benefit.

And I use them with my clinical patients, as well as for myself. Worth noting is that this device is not my first recommendation for treatment. My first recommendation is free-to-use. I’ll speak to these and more next week …

Conclusions?

As you can see from the side-by-side image above, both of these men are scientists from world-renown universities - Stanford and Harvard.

One of these scientists has a career focused on circadian rhythm discoveries leading to the well-earned name ‘The Light Doctor’ - the other has primarily studied mice eyes and is now regarded as one of the most influential Broscientists.

Both men have been promoting the use of blue-blocking glasses in the past month.

And it appears both men receive some coin when a pair of BB glasses is sold (sometimes you have to read the fine print .. here’s Dr Moore-Ede’s …)

Part of the theory about ‘influence’ delves into the Message and the Messenger. Is it just me, or are too many people focused on the credentials of the Messenger? If that’s the case, then for those who care, here’s another side-by-side comparison (see image below).

For those wise enough to look beyond the Messenger, then please consider the following ...

Follow the science, not scientists … including …

• Prof MG