A Surprisingly Easy Weapon Against The Flu

It’s that time of year, and flu is on the rise. So is COVID, so is RSV, and so are various other infectious pathogens.

See for example: COVID, flu, RSV: how these common viruses are tracking this winter, and how to protect yourself ← this is news from Australia, which is of more relevance than one might think when it comes to those of us in the Northern hemisphere, as Australia’s flu season being 6 months ahead of ours can give a good indicator of how things are going to go for us when our own winter hits.

^{Note for any confused: due to axial tilt, seasons in the two hemispheres are mirrored. So while you’re probably familiar with the seasons being tied to specific calendar months and popular media (centred around N. American and European experiences) can make that seem very one-sided, it’s important to remember that June, July, and August are winter months in the Southern hemisphere, and December, January, and February are summer months.}

Which brings us to our main topic today…

It’s about time!

There’s a lot that can be done to improve one’s chances against the flu et al., and we’ve written about that from time to time before, for example:

Why Some People Get Sick More (And How To Not Be One Of Them) ← including some very important things that many people don’t know!

But more recently, researchers (Dr. Martina Towers et al.) have found that a person’s underlying circadian rhythm can directly influence how well the body responds to flu infection (and, presumably, other infections too, but this was about influenza A.

This is not too surprising, because circadian rhythms regulate biological processes in individual organs and cells, and external cues—especially light and mealtimes—help synchronize these clocks, and thus play a part in regulating immune response.

You may be wondering: why does the body care what time it is when it comes to fighting an infection? Isn’t a flu infection casus belli for total war, and thus around-the-clock wave after wave of immune defense deployments?

And yes, it is. But consider: we’ve previously used the example of firefighters, when talking about acute vs chronic inflammation (we’ll link that article at the bottom of this section, for your references). That the problem with chronic inflammation is that the firefighters are overworked and exhausted after responding to a bajillion false alarms or trivial things that were not really the business of the fire service, so that when an actual fire breaks out, they’re not in good shape to combat it.

Let us add to this metaphor a little, and ask the question: what happens if all the firefighters are confused about what time it is? Will they coordinate well together, show up to shift on time, get a good night’s sleep after a day’s work, and so forth? No, there will be big gaps in the service; there will be times when there are too many firefighters trying to crowd into one place, and times when there’s a nobody around to answer the calls.

So it is with your immune system too.

Dr. Towers and her team tested this, and in so doing, showed how disrupting normal lighting patterns during a critical window removed the usual time-of-day protections (i.e., that immune response is usually better in the morning, for example) and produced an abnormal immune response, including excess inflammatory cells in the lungs. They also found that keeping a rhythmic meal schedule at least somewhat reduced the harm caused by disrupted light cues. Thus, it’s clear that both light/dark and appropriate regular mealtimes are important for this kind of regulation, and that while they work best if you have everything correct, getting one aspect correct (e.g. just the dark/light, or just the meal schedule) is already better than nothing.

You can read the paper in full, here: Effect of external cues on clock-driven protection from influenza A infection

This is also consistent, of course, with the generally good advice of “try to get good sleep”, which was item #1 in a previous main feature of ours:

Beyond Supplements: The Real Immune-Boosters!

And see also, for that matter: What Harm Can One Sleepless Night Do? ← this is about how bad sleep ruins immune response, and is where we used to firefighters metaphor previously

In summary…

If you want to be able to fight the flu, then you need to take care of your circadian rhythm. For more on that, see:

The Circadian Rhythm: Far More Than Most People Know

…and:

The Other Circadian Rhythms

Want to learn more?

Check out:

The Pathogens That Came In From The Cold: The Cold Truth About Respiratory Infections

Take care!