Sauna, Cold Water and Red Light

Patients often ask me whether saunas, cold plunges and red light panels help. Each has some real science behind it and a great deal of marketing on top, in this video I'll help you separate the two. The evidence is thinner than the marketing suggests; because major cancer guidance on managing tiredness and pain doesn’t mention saunas, cold water or red light at all. That doesn't mean they're harmful or worthless, only that nobody has yet shown they improve an outcome that matters in cancer care. There is one narrow exception, which I'll come back to. Sauna is a good example, because most of the research comes from one group of middle-aged men in Finland. That study included no women and nobody who'd had breast cancer treatment; so its findings may not apply to you. Heat also raises your heart rate and lowers the resistance in your blood vessels, which is something to be careful of if you have certain heart conditions. Cold water is similar, and you may have read that it reduces inflammation, but the trials suggest otherwise. When they're pooled, markers of inflammation actually rose afterwards and stayed raised an hour later. Many people say they feel better after cold water, although the trials found no measurable effect on mood. Even the cold shower trial that's often quoted found that people took fewer days off sick, but they weren't actually ill any less often. They simply went to work on days when they'd previously have stayed at home. One cold-water finding is consistent across the research, and it matters if you do strength training. Regular cold water immersion, straight after a session, reduces the strength and muscle you would otherwise gain. Also, alternating hot and cold hasn't been shown to add anything; and a cold plunge between saunas may blunt the body's response to heat. Red light treatment, which clinicians call photobiomodulation, is the one narrow exception that I mentioned at the start. It's recommended to help prevent painful mouth ulcers during a stem cell transplant or radiotherapy to the head and neck. There, it's given by trained clinicians as part of treatment. Small trials also support it for preventing skin reactions during radiotherapy, and most of those were in women with breast cancer. However, the laser light was given by clinicians from the start of treatment, which is very different from a panel bought online. Whatever the possible benefits, the safety cautions matter more once you've had breast cancer treatment. If you have lymphoedema, or you're at risk of it, NHS advice is that the heat of a sauna or steam room may increase the swelling. Skin that's numb after surgery can also burn without you noticing. Some heart conditions call for extra care, so please take advice before a sauna if you have unstable angina or a recent heart attack. The same applies to a severely narrowed heart valve or an irregular heartbeat that isn't controlled. Cold water needs similar care if you have heart disease or take medicine that slows your heart. Cold water brings its own danger, because cold shock starts within seconds and the first minute is the riskiest, so never swim in open water alone. And, with red light, protect your eyes; and don't use it over your breast; scar; or armpit unless your oncology team agrees. Whichever you try, stop and get out if you have chest pain, palpitations or feel faint during or after heat or cold. Call 999 if chest pain lasts more than a few minutes or you feel faint, and tell your breast care nurse about any new swelling. Overall, a sauna is pleasant and may well be good for you, although the evidence can't yet prove it. If you're thinking of trying any of these during treatment, please get in touch with me or my team.