"Sauna bathing may be linked to several health benefits, which include reduction in the risk of vascular diseases such as high blood pressure, cardiovascular disease, and neuro-cognitive diseases," explain the scientists behind a recent report published in Mayo Clinic proceedings. And they have a good idea about why. These scientists also published a study earlier in 2018 that used 100 test subjects who spent 30 minutes in a sauna, and examined what happened to their hearts. And the results are illuminating.

Half an hour in a sauna, the research showed, lowered both systolic and diastolic blood pressure. These two numbers are what give your normal blood pressure reading: 'systolic' is the pressure on your blood vessels during a heartbeat, and 'diastolic' is the pressure between beats.

Saunas, according to this research data, can help "vascular compliance," or how well your blood vessels respond to changes in pressure. That's a massive factor in the health of your heart and in how effectively your blood travels throughout your body, including to your brain.

Saunas, it turned out, make your blood vessels really responsive to pressure, and also heighten your heart rate; it was pretty common, according to the scientists, to see peoples' heart rates increase as if they were doing some moderately intensive exercise

A few different studies have shown that there's a link between frequent sauna-taking and a lower risk of early mortality, though it's only been studied in men. A study of 2,300 Finnish men over 20 years found that, over the course of the study, 49% of once-weekly sauna takers passed away, compared with 38% of twice-weekly users and 31 percent of men who went nearly every day.

Part of this, the scientists behind the study say, is that saunas are often done communally, and help you bond with other people, which has confirmed health benefits of its own. Plus they're meant to be relaxing and meditative. But the blood pumping effects seem to be making a difference, too.

The people in the sauna study also showed evidence of artery relaxation after half an hour of spa time, which is an indicator of good heart health. You do not want arterial stiffness, because it raises your risk of cardiovascular issues and diseases. The stiffer your arteries, the more likely you are to have a heart attack or suffer some kind of bypass. This sounds contradictory, as many saunas recommend staying away if you have heart disease or heart problems, but other studies have shown that even for patients with serious heart disease, saunas can be helpful. However, you should still refer to a physician before you go if you've suffered a heart attack or have a history of cardiovascular issues.

Better blood flow doesn't just help your body; it also helps your brain. The benefits of saunas, Leigh Ann says, "include improved sleep and relaxation, improved mood, reduced and improved symptoms of depression and anxiety, and decreased risk for dementia and Alzheimer's disease." The research rounded up by this latest study shows that, in older Finnish men, having many sauna sessions a week was linked to a substantially lower risk of Alzheimer's and dementia. But there's a risk in saying there's cause and effect here.

"Whether sauna exposure exerts its neurocognitive protective effects or it is just an enjoyable activity that prevents or delays the development of these memory diseases is not clearly understood," explain the scientists. Hanging out with your friends and doing the crossword in a sauna may be the real hero here, not the sauna itself.

"Sauna bathing has been linked to an improvement in pain and symptoms associated with musculoskeletal disorders such as osteoarthritis, rheumatoid arthritis, and fibromyalgia," the new study says. And chronic-type headaches are also included in their pain-busting properties.

Why? Partially, scientists believe, it's because saunas appear to reduce inflammation levels in the blood. In several chronic pain conditions, inflammation goes haywire to cause serious pain and fatigue, and saunas appear to reduce those markers. This isn't a cure, only a temporary reprieve, but for some it may be a serious benefit.

Having a sauna when you've got a cold or are in the middle of cold season might seem counterintuitive, but the research suggests it's a good idea. Studies have shown that saunas can improve your lung function, even if you have asthma or chronic breathing problems, and reduce your risk of contracting a cold or pneumonia if you have them regularly in winter. This may not counteract somebody in the sauna sneezing on you, but when you're feeling shivery in your apartment when it dips below freezing, it may be a good idea to get thee to a sauna.

If you're just beginning to enjoy saunas, Leigh Ann urges caution. "Ease in to your sauna sessions," she says. "Most doctors recommend starting with five to 10 minutes, two to three days a week. If you maintain consistency, you will notice that your tolerance will begin to rise and you will be able to stay in longer. Aim for 20 to 40 minutes, three to five days a week for optimal health benefits." You can't rely on a sauna to give you every health advantage you need to live a healthy life; balanced nutrition and exercise matter, too. But the evidence suggests that you should could consider adding them into your routine when things get a little colder.