Sauna use trimmed cholesterol in under-60s; over-60s saw nothing

Unhealthy blood lipid profiles, known as dyslipidaemia, are a significant risk factor for cardiovascular disease, and treatment has traditionally leaned on medication. Passive heat therapies such as hot springs and saunas have recently attracted attention as alternatives, because of potentially beneficial effects on lipid profiles and cardiovascular health. If sitting in heat genuinely nudged cholesterol in the right direction, it would be an unusually pleasant intervention to prescribe. This review set out to synthesise the trial evidence, including whether heat works better when combined with exercise therapy.

The authors followed PRISMA guidelines and searched major databases, turning up 330 records, of which 127 studies went forward to blinded screening using the Rayyan review platform. Seven randomised controlled trials met the inclusion criteria: trials testing hot spring or sauna use, alone or combined with exercise therapy, on blood lipid profiles in adults. The trials split naturally by age, with four conducted in groups whose mean age was under 60 and three in groups with a mean age of 60 or above. An expert panel then weighed the evidence and issued recommendations.

In the four trials of younger adults, hot spring and sauna use produced reductions in serum total cholesterol and low-density lipoprotein cholesterol, the fraction most closely tied to cardiovascular risk. On that basis the expert panel gave these therapies a weak recommendation, a deliberate signal that the evidence is suggestive rather than firm. The three trials in older adults found no significant changes in blood lipids at all. The authors highlight that the benefit appeared particularly when heat was combined with exercise therapy.

Heat therapies have gained attention for cardiovascular health, but strategies for managing dyslipidaemia have so far been built around drugs rather than bathing habits. This review is an early attempt to test whether the lipid claims survive contact with randomised trials, and the answer is a qualified, age-dependent maybe. The split between younger and older adults is the most intriguing loose end, since nothing in the trials explains why the over-60 groups saw no change. The authors suggest that emerging intervention studies could eventually inform guidelines on integrating these therapies into dyslipidaemia management.

For a sauna or hot spring enthusiast under 60, this is tentative evidence that the habit may nudge total and LDL cholesterol downward, especially alongside exercise. The experts behind the review would be the first to call that recommendation weak, and nothing here suggests heat can stand in for standard care. For older adults, the trials so far show no sign of a lipid benefit, which is worth knowing before anyone sells heat as cholesterol therapy. Enjoyment, rather than lipid numbers, remains the most defensible reason to book the session.