Cooling down after a sauna is a real health boost, say experts

Is sauna bathing good for you? Here’s what the science says

Fri, 04 Oct, 2024 - 02:00

Dr Catherine Conlon

Over the summer, I visited a sauna in Ballinskeilligs overlooking the beach, alternating between inhaling steamed lemongrass and dipping into the Atlantic Ocean. It felt blissful and exhilarating simultaneously, a welcome opportunity to sink into dry heat and ease mind and body tensions.

Experts believe sauna bathing may benefit arthritis, chronic fatigue, cold symptoms, muscle soreness, and stress.

Sitting in a sauna may also be particularly good for your heart. Research published in JAMA Internal Medicine (2015) suggests that frequent sauna bathing is linked to a reduced risk of fatal cardiovascular and all-cause mortality outcomes.

Also, knowing more about the combined effects of sauna bathing and exercise on cardiovascular health could help people manage cardiovascular risk factors.

A study from the University of Jyväskylä, Finland, conducted a randomised control trial (RCT) to compare the effects of sauna bathing and exercise with exercise alone on cardiovascular health.

The researchers found that combining sauna bathing with exercise improved heart health more than just exercising in terms of lowering blood pressure and improving cardiorespiratory fitness (CRF).

The 2022 study, published in the American Journal of Physiology, concluded that a typical 15-minute sauna three times per week after exercise supplemented the gains in CRF, reductions in systolic blood pressure, and considerably lowered total cholesterol levels.

A systematic review combining results of the health benefits of saunas published in 2018 in Evidence Based Complementary Alternative Medicine reported the health effects of regular dry sauna bathing that included 40 clinical studies involving a total of 3,855 participants.

It found that the most established clinical benefits are associated with cardiovascular disease. Yet, there is also evidence to suggest that saunas, either Finnish-style or infrared, may benefit people with rheumatic diseases such as fibromyalgia, rheumatoid arthritis, and ankylosing spondylitis, as well as patients with chronic fatigue and pain syndromes, lung conditions such as chronic obstructive pulmonary disease (COPD), and allergic rhinitis. Sauna bathing may also improve exercise performance in athletes, as well as quality of life indicators, and is not associated with serious adverse effects.

The review authors suggested there is insufficient evidence to distinguish any particular health differences between repeat Finnish-style and repeat infrared sauna bathing.

Dr Catherine Conlon is a public health doctor in Cork and former director of human health and nutrition, safefood

Long-term studies in Finland found a correlation between regular sauna use and the reduced risk of developing dementia and Alzheimer’s disease.

Researchers at the University of Finland found that middle-aged men who took a sauna more than four times a week were two-thirds less likely to develop Alzheimer’s disease or dementia over 20 years. The researchers followed 2,315 men aged 42- 60 years as part of the Kuopio Ischaemic Heart Disease Study.

Men who reported taking a sauna four to seven times per week were 66% less likely to receive a diagnosis of dementia than those who only had a sauna once a week. They were also 65% less likely to receive a diagnosis of Alzheimer’s disease.

The analysis accounted for differences in age, blood pressure, alcohol use, smoking, blood cholesterol, and other health conditions between the groups.

More recent research has looked at the benefits of heat therapy in the treatment of depression.

A study published in Scientific Reports earlier this year investigated the link between depression and higher body temperature. Lead author Dr Ashley Mason, associate professor of psychiatry at the University of California San Fransico (UCSF), told Medical News Today (MNT) that increases in body temperature engage the body’s self-cooling mechanisms, such as sweating — and can lead to decreases in body temperature — a person sweats, they cool themselves down.

The study analysed data from more than 20,000 participants from 106 countries. All wore a device measuring body temperature and self-reported their body temperatures and depression symptoms each day for seven months.

The researchers found study participants had higher body temperatures with each increasing level of depression symptom severity.

Dr Mason suggests the link between depression and body temperature may be explained by inflammation.

“Inflammation may be a factor and we’re looking at this in our ongoing work. Thermosensory pathways may also play a role — these pathways relay sensory information from our periphery (skin) to our central nervous system. We can think of them as gateways to neural systems that impact our mood and cognitive function,” she concluded.

The researchers suggested that novel therapies to lower body temperature — such as heat therapy through a hot tub or sauna — might benefit mental health.

MNT also spoke to Dr Gary Small, chair of psychiatry at Hackensack University Medical Centre in New Jersey, who was not surprised by the study findings.

“Previous research has shown that hot baths help mitigate mood symptoms, and this study suggests that our body’s ability to cool down from such warmed states may yield the antidepressant effect.”