Since ancient times, saunas have been used for relaxation and wellness. Now, multiple studies are suggesting that enjoying a good sweat can also help to stave off heart disease, stroke and even dementia.

Researchers from the University of Eastern Finland tracked more than 2,300 men for longer than two decades and found that subjects who used saunas regularly had a 63 per cent decrease in deaths from heart attacks and strokes. They also found a 66 per cent reduction in cases of dementia and Alzheimer's disease.

The researchers also discovered that the frequency of sauna sessions played a dramatic role in how protective the practice was for the men's health. They noticed improvements in blood pressure, blood flow and heart function in as little as four sauna sessions a week over a two-month period.

The study's lead author, Jari Laukkanen, told CTV News that previous studies have shown that some brain diseases and cardiovascular diseases may share some of the same risk factors, which could explain why sauna bathing can help defend against both groups of diseases.

"I think it's very significant because we have not seen that a lifestyle factor can be so protective against (a) number of cardiovascular diseases," Laukkanen said.

Scientists call the practice "passive heat therapy" and suspect the health benefits are because the sauna raises the body's core temperature. Daniel Gagnon, a researcher at the Montreal Heart Institute, explained that the increased heat promotes better blood flow.

"The main theory is that really, it resembles exercise," Gagnon said. "When we get hot, our heart rate increases, our blood vessels dilate or open up in the skin. It's really that increase in blood flow that is thought to provide the benefits of heat in terms of cardiovascular health."

Gagnon said he is planning two more studies on saunas, one in healthy adults, the other in those with heart failure, using a sauna within the Montreal Heart Institute.

"If we can just give simple lifestyle habits to individuals that they can use on a day-to-day basis, I think that would be very powerful," Gagnon said.

Some earlier studies have suggested that there are harmful effects to saunas, such as increased itching for patients with pre-existing dry skin conditions. The Finnish researchers found no negative effects from increased sauna use and speculated that may be because of the dry heat and high temperatures used in Finnish saunas.

The research is welcome news to Julia Tourianski, the manager of a Russian-style sauna and tearoom in west Toronto.

"It is validating old cultural knowledge, things my grandparents knew," said Tourianski, who says business is booming this winter.

"Last week we had the heavy snowfall and we get slammed because people are feeling chilled to the bone and they need to get warm," Tourianski said.

Sauna patron Ian Russell says he finds the sauna relaxing.

"To me, when you walk out of here, you feel like you're six inches taller, like you could walk on water," said Russel.

With files from CTV's medical specialist Avis Favaro and producer Elizabeth St. Philip