Ever since I wrote the blog post on yoga perpetuating the appeal to nature fallacy, I’ve been a little paranoid about my potential role in overselling the value of yoga for health.
In fact, almost immediately after writing that, I had a bit of a panic attack about my recent “Yoga for immune balance” programme for MoreYoga and how that might be perceived by anyone who watches it (to the point where I had to email them to ensure there was a disclaimer somewhere saying that this is not medical advice etc etc). I’m still worried about what I said and how it will be perceived, but they already probably think I’m a diva so I’m letting it go. (in case you are wondering, the programme is not out yet but I will post a link when it is).
Anyway, I digress. The point is, I feel like it’s time for a little clarity.
What do we actually know about the effects of yoga on the immune system?
You should know that non-immunologists hate immunology, even when they have a science/life science background. They say it’s complicated and confusing and has too many acronyms. When I used to work at Nature, copy editors would always complain when they had to cover immunology. This is a good article on this very topic in the context of COVID-19.
Personally, I don’t think it’s more complicated than other disciplines – surely the brain is far more complicated and incomprehensible! But hey, I’m biased. Regardless, I will try using my best science communication powers to convey my thinking in the clearest possible way.
1. Yoga (and other mind–body practices) influence the expression of genes involved in inflammation
Let me unpack that fairly jargony statement. Inflammation is a bodily reaction whereby cells of the immune system gather at a certain place (your gut, your skin and so on) to deal with an attack by pathogen (like a virus or a bacterium), an injury or the presence of a harmful substance. In essence, it’s a response that helps the body heal itself.
To do this, the cells need to know that they need to go to wherever it is that the problem is. This means that other cells, be they infected cells or cells that at the site of injury or other immune cells, need to send out a signal to say “hey, you have to come quick and help sort out this mess”. This signal is usually inflammation-promoting proteins called cytokines, although there are other distress signals too that can also act like a flare gun to alert of where the problem is. But for the purpose of this discussion (and for the sake of simplicity), we’ll focus on cytokines.
The cells make these proteins by switching on the genes that express them – genes being components of our DNA that are inside every cell. When the genes are switched on, the specialist machinery inside the cell translates the information that is in the gene into a functional protein, in this case an inflammation-promoting cytokine.
There is evidence that yoga (and other mind–body practices) reduce the expression of genes that code for these inflammation-promoting cytokines (see this older post, as well as here, here and here). The upshot is, less unnecessary inflammation.
|Why is reducing inflammation a good thing?|
What we want is a balanced immune system – one that is active and strong when we need it to be (ie against foreign invaders or cancer cells) but not so active that we have unnecessary inflammation and even autoimmune disease.
Chronic stress can have a detrimental effect on the body partly because it drives constant low levels of inflammation. This has been linked to a number of diseases, including heart disease, metabolic diseases like diabetes, and Alzheimer’s disease. In fact, measuring this constant low level inflammation has been proposed as a way to more accurately assess how old we really are.
BUT, to make things a bit confusing, chronic stress can also lead to an under-active immune system. Perhaps the easiest way of thinking about it is that chronic stress throws things off-kilter (and potentially yoga brings back balance). So yeah, I suppose it is complicated!
2. Yoga has beneficial effects in diseases involving an overactive immune system
The obvious place to look here is autoimmune diseases – these are diseases where immune cells have gone a little rogue and can no longer make the distinction between what is ‘self’ and what is ‘non-self’, which means they start attacking the body. I’m sure you know what these are, but just to give some examples, they include type 1 diabetes (where the immune system attacks and destroys the cells in the pancreas that produce insulin), Crohn’s disease and ulcerative colitis (where the immune system attacks the gut) and rheumatoid arthritis (where the immune system attacks the joints).
There is some evidence that yoga can help alleviate the symptoms in those living with an autoimmune condition. For instance, I previously wrote about a study where participants who did yoga alongside taking their medication had significantly lower levels of inflammation-promoting proteins and showed improvements in disease activity, compared with those who took medication alone. There is also some evidence in Crohn’s and ulcerative colitis.
Unfortunately, to my knowledge there aren’t a lot of studies where the researchers measure the effects of yoga on inflammation-promoting proteins – most studies look at impact on alleviating symptoms and quality of life (and generally find beneficial effects). So it’s kind of hard to say what it is that yoga does to improve disease activity; certainly a topic I would like to look into a bit more and write about in the future.
Other diseases that involve inflammation
The other interesting example is depression, which is in fact thought to be cause by inflammation too even if it’s not traditionally considered to be an autoimmune disease. There is evidence that yoga can help to improve the symptoms of depression, and it is therefore possible that it achieves this by tackling inflammation, exactly as happens with autoimmune disease (see more on this here).
However, to my knowledge there is no research that specifically looks at whether yoga lowers the levels of inflammation-promoting proteins in patients with depression, so this remains a very interesting possibility that has yet to be shown directly.
3. Yoga and specifically stretching have been linked to resolving inflammation
I don’t want to place too much emphasis on this one as I had massive caveats when I wrote the post about it, but basically there is some evidence to show that stretching can help to resolve localised inflammation in the connective tissue, or the fascia. This may be, at least in part, why yoga can help to alleviate back pain.
So what does it all mean?
My non-yoga, sciency friends were surprised when I told them I was filming my “yoga for immune balance” course – does yoga really support the immune system, they wondered. The evidence so far suggests that it does, support being the key word.
We all know that chronic stress is bad for us, and, as mentioned above, chronic stress can also lead to this constant low level inflammation that is terrible for our health. I believe that the way that yoga benefits the immune system is by acting on this chronic stress pathway and relieving some of its detrimental effects. It’s that mind–body connection: how we feel affects our body, and by making us feel better and less stressed, yoga can help our body too, including our immune system.
However, yoga is not a magic bullet.
I cannot stress this enough!
Yoga will not make your immune system so strong that you don’t need to be vaccinated against COVID-19 (or flu or other things).
Yoga is unlikely to replace your medication if you have a chronic disease, for instance an autoimmune disease or heart disease. It won’t cure your cancer either.
Yoga will not give you superpowers, despite what proponents of natural health say.
What it can do it is help you stay healthy and feel better overall – it’s a great way to complement traditional medicine in improving quality of life.
And regardless of what the wellbeing industry is telling you, you don’t want a boosted immune system, whether that’s achieved by yoga or other means (here’s my mini-rant in my latest newsletter and a TED talk explaining why it’s all about balance).
Enjoyed this blog post? You can now buy me a coffee and keep me caffeinated to research and write.