The Medscape news site bills itself as the leading online global destination for physicians and healthcare professionals worldwide.
This week’s leading story posed a hot and sultry question: “Is it time to start recommending regular sauna bathing to improve heart health?”
Medscape was moved to ask this question based on study findings from the past eight years – and because too few people are doing sufficient exercise.
And so their expert answer is ‘yes’.
Sitting in a sauna for 20 to 30 minutes, several times a week, “can produce some of the same cardiovascular benefits as aerobic exercise”.
This is particularly useful for older people who aren’t up to a vigorous workout.
However, just like exercise, the benefits come with frequent use.
Protection from sudden cardiac death
A 2015 study by Finnish, US and Italian researchers suggests that “men who engaged in frequent sauna use had reduced risks of sudden cardiac death, fatal coronary heart disease, fatal cardiovascular disease and all-cause mortality.
The study involved 2315 middle-aged men (aged 42 to 60) from eastern Finland.
Compared with men who reported one sauna bathing session per week, the risk of sudden cardiac death was 22 per cent lower for two to three sauna bathing sessions per week – and 63 per cent lower for four to seven sauna sessions per week.
For more results see here.
Protection from dementia and stroke
A 2016 study from the University of Eastern Finland and University of Bristol found that sauna bathing may reduce the risk of dementia and Alzheimer’s disease.
In a 20-year follow up, men taking a sauna four to seven times a week were 66 per cent less likely to be diagnosed with dementia than those taking a sauna once a week.
The association between sauna bathing and dementia risk had not been previously investigated.
These same researchers led a 2018 study – with a 15-year follow up – that found men and women who sat in a sauna four to seven times a week were 61 per cent less likely to suffer a stroke than those taking a sauna once a week.
How is this happening?
The researchers suggest “a reduction in blood pressure, stimulation of the immune system, a positive impact on the autonomic nervous system, and an improved cardiovascular function might all be contributing to reducing stroke risk”.
Blood pressure drops
People with pre-existing low blood pressure are advised to avoid saunas – and a further drop in blood pressure – because of fainting afterwards.
This reported drop in blood pressure – one of the benefits of exercising your heart – occurs after sitting in a sauna session.
During a sauna session, your heart rate and blood pressure increase, as they would in a workout.
In 2019, German researchers found that “a sauna session is just as exhausting as moderate exercise”.
What Medscape says
The Medscape piece talks about the hormetic effects (known as hormesis) of sauna heat therapy producing “significant gains for microvascular and endothelial function”.
Hormesis is the idea that putting the body under a mild stress – using mild doses of an agent, such as heat, that would be toxic at higher exposures.
Some research has looked at the effects of mild heat stress of anti-ageing, longevity and cell repair.
The potential of mild heat stress as a therapy for cardiovascular decline, a global health issue, has become serious area of research in recent years.
For example, mild heat stress has been found to reduce arterial stiffness and improve blood flow.
Medscape advises: “The mechanisms by which heat therapy improves cardiovascular fitness have not been determined, as few studies of sauna bathing have been conducted to this degree.”
One driver appears to be cutaneous vasodilation. This is where the body works to cool down when exposed to extreme external heat.
How so? Cutaneous vessels dilate and push blood to the skin. This lowers body temperature and increases heart rate. This in turn “delivers oxygen to muscles in the limbs in a way similar to aerobic exercise”.
The attraction here is that heat stress therapy requires little effort. Which will suit people who otherwise make no effort to improve their cardiovascular health.
But talk to your doctor first and don’t overdo it. The trick here is mild stress.
In 2010, a competitor at the World Sauna Championships in Finland died after collapsing with severe burns in 110-degree Celsius heat.
