Hot but not bothered

When it comes to optimising brain health, short cuts for the most part are a fool’s errand and the unpalatable truth is that if you really want to optimise and protect your brain over the long term, you must put in the work over the long term.

This is the case for many things that we know are good for your brain – following the Mediterranean diet for instance, or optimising sleep or exercise.

When examples of “hacks” that do work emerge, then I can’t help but get excited. I have mentioned before about the use of sauna bathing, and I think this is one such example of a pleasurable pursuit that requires little effort and yet which seems an effective strategy for boosting your brain. Most of the studies that have researched the benefits of sauna come from (perhaps unsurprisingly) Finland or Japan.

The types of sauna used differs between the countries, with the Finns using the traditional coals-in-a-hot box approach and the Japanese using a type of infra-red sauna known as Waon therapy. Both seem to help the body and brain.

Before we jump into why it works, it is good to appreciate what specific benefits sauna confers.

These include up to a 50 per cent reduction in risk of death from cardiovascular disease and a 40 per cent reduction in premature death from any cause. It is known to improve blood pressure and the health of your heart. It is also known to reduce inflammation – pertinent to all manner of chronic diseases, including dementia.

There is even evidence that it creates the same benefits as aerobic exercise – so you can be hot, but not bothered.

In animals at least, sauna-like conditions have also led to increased lifespan, and some of this may be due to hormesis: putting the body under stress so that it is forced to adapt. This improves cell function, essentially revving them up.

And studies also have shown a link between regular sauna use and a substantially reduced risk of dementia, even accounting for the fact that those who use sauna may engage in other healthy lifestyle practices.

Though the link is only observational – we cannot fully conclude that sauna causes the reduced dementia risk – there is a so-called dose effect: the more you use the sauna, the lower your risk.

This supports the idea of it being causative. Indulging four times a week, for at least 20 minutes seems to be especially effective (between 80 and 90 degrees centigrade ideally).

But why does it work? Well, it is not fully understood, but in addition to the hormetic effect above, it increases pulse rate (up to 150 bpm) and blood pressure.

This over the long run conditions the vascular system and improves blood flow, including to the brain. So called heat shock proteins – produced by sauna bathing – also seem to interact with amyloid, a protein involved in Alzheimer’s disease – to prevent it clumping in the brain and causing damage.

Sauna also increases the level of one of my favourite molecules, BDNF, which is critical for growing new nerve cells maintaining their health.

So, I am a big exponent of sauna, but of course you should discuss with your doctor whether it is safe for you personally and follow professional guidance about how to use it. Unstable angina is a contraindication as is a recent heart attack or certain heart valve abnormalities.

Lastly, I am not recommending you substitute sauna for exercise! Though the former might mimic the latter in some ways, exercise has its own independent benefits, and doing them both is better than just doing one.

Kailas Roberts is a psychogeriatrician and author of Mind your brain The Essential Australian Guide to Dementia now available at all good bookstores and online. Visit yourbraininmind.com or
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