Regular saunas may reduce cardiovascular death rates

Regular saunas may reduce men and women’s cardiovascular death rates, a new study has found. Regular saunas also reduce their risk of developing cardiovascular disease (CVD). The study focused specifically on males and females aged 50+ years.

Cardiovascular diseases are diseases that involve the heart (cardio) or blood vessels (vascular). Stroke, coronary artery disease, and heart attack (myocardial infarction), for example, are cardiovascular diseases. Atrial fibrillation, angina pectoris, and cardiomyopathy are also types of cardiovascular diseases.

A team of Finnish, British, and American researchers wrote about their study and findings in the journal BMC Medicine (citation below). The authors were Tanjaniina Laukkanen, Setor K. Kunutsor, Hassan Khan, Peter Willeit, Francesco Zaccardi, and Jari A. Laukkanen.

Comparing two groups that took regular saunas

The researchers compared the CVD mortality rates of people who took saunas 4-to-7 times a week with those who took them once a week.



There were 2.7 fatal CVD events per 1,000 person-years among men and women who used a sauna 4-to-7 times a week. The rate for those who used a sauna once a week was 10.1 per 1,000 person-years.

The term ‘person-years’ refers to the participants’ total or combined number of years in the study. We measure in person-years when we want to know how many new events there have been in a study population over a specific period. A high number of events indicates a greater risk.

Regular saunas reduce cardiovascular disease risk and deaths
In an Abstract that preceded the main article in the journal, the authors wrote: “Higher frequency and duration of sauna bathing are each strongly, inversely, and independently associated with fatal CVD events in middle-aged to elderly males and females.”

Previous studies focused on men only

Professor Jari Laukkanen, from the Institute of Public Health and Clinical Nutrition at the University of Eastern Finland, said:

“An important finding of this research is that more regular sauna use is associated with a lower risk of death from CVD in middle-aged to elderly women as well as in men. Previous population studies were done mostly in men only.”



“There are several possible reasons why sauna use may decrease the risk of death due to CVD. Our research team has shown in previous studies that high sauna use is associated with lower blood pressure. Additionally, sauna use is known to trigger an increase in heart rate equal to that seen in low to moderate intensity physical exercise.”

The researchers also noted that CVD mortality incidence was associated with users’ length of time in saunas each week.

The incidence of CVD mortality was 5.1 per 1,000 person-years for people who spent 45+ minutes each week in a sauna. The figure was 9.6 for those who spent less than 15 minutes each week.

Participants answered questionnaires

Participants reported their use of saunas in questionnaires. The authors checked deaths from CVDs against death certificates and documents from health center wards and hospitals. They also checked medico-legal reports. The study included 1,688 participants who lived in or near Kuopio in Finland.



At the beginning of the study, the average age of the participants was 63 years – 51.4% were women.

The researchers analyzed and gathered data between 1998 and 2015. The mean follow-up time was fifteen years.

Citation

Sauna bathing is associated with reduced cardiovascular mortality and improves risk prediction in men and women: a prospective cohort,” Tanjaniina Laukkanen, Setor K. Kunutsor, Hassan Khan, Peter Willeit, Francesco Zaccardi, and Jari A. Laukkanen. BMC Medicine 2018, 16:219. DOI: https://doi.org/10.1186/s12916-018-1198-0.