Why Sauna Bathing Is Good for Your Heart Health
Over the past couple of years, scientists at the University of Eastern Finland have shown that sauna bathing is associated with a variety of health benefits. Their latest study with 100 test subjects shows that taking a sauna bath of 30 minutes reduces blood pressure and increases vascular compliance, while also increasing heart rate similarly to medium-intensity exercise.
Previously, the research group has published findings from a population-based study indicating that regular sauna bathing is associated with a reduced risk of coronary diseases and sudden cardiac death1, hypertension2 and Alzheimer’s disease and dementia3. Frequent sauna bathing has also been associated with a reduced disk of respiratory diseases4 and lower CRP levels.
The experimental study carried out in the Sauna and Cardiovascular Health project provides new insight into changes that take place in the human body during and after having a sauna. The study analyzed the effects of a 30-minute sauna bath in 100 test subjects. In particular, the objective was to analyze the role of vascular compliance and reduced blood pressure in the health benefits caused by sauna bathing.
Vascular compliance was measured from the carotid and femoral artery before sauna, immediately after sauna, and after 30 minutes of recovery. These vascular compliance measurements carried out in the experimental study constitute a new assessment method in a sauna setting.
Immediately after 30 minutes of sauna bathing, test subjects’ mean systolic blood pressure reduced from 137 mmHg to 130 mmHg, and their diastolic blood pressure from 82 mmHg to 75 mmHg. Furthermore, their systolic blood pressure remained lower even after 30 minutes of sauna bathing.
Test subjects’ mean carotid-femoral pulse wave velocity, which is an indicator of vascular compliance, was 9.8 m/s before sauna, decreasing to 8.6 m/s immediately after. During sauna bathing, test subjects’ heart rate increased similarly to medium-intensity exercise, and their body temperature rose by approximately 2°C.
The findings shed light on the physiological mechanisms through which health benefits, which have been observed at the population level and are caused by the heat exposure of sauna, may develop.
The findings on the effects of sauna bathing on the human body were published in the Journal of Human Hypertension, and the findings relating to the carotid-femoral pulse wave velocity measurements were published in the European Journal of Preventive Cardiology.
Research indicates that regular physical exercise and a healthy lifestyle promote cardiac health and prevent disease, but not all of the risk and protective factors are yet known.
The benefits of regular sauna bathing on cardiac health observed in the population-based study can, according to this experimental study, be explained by the fact that sauna bathing reduces blood pressure and increases vascular compliance.
However, further research data from experimental settings relating to the physiological mechanisms of sauna bathing that promote cardiac health is still needed.
Excess fat disrupts heart cell’s energy system
A University of Iowa study has identified how excess fat in the heart, a common feature in diabetes and obesity, can harm the cells’ essential ability to produce energy. Researchers believe the mechanism may contribute to the two- to five-fold increased risk of heart failure in people with diabetes.
The heart is the most energy-hungry organ in the body. Just like a combustion engine burning fuel to power the pistons, healthy heart cells consume fuel molecules to create the necessary energy to keep the heart pumping. This essential energy production takes place inside mitochondria, the self-contained “powerplant” organelles inside cells.
Although mitochondria in a healthy heart primarily use fatty acids as fuel, they can easily adapt to use other fuel molecules as needed, including glucose, lactate, and ketone bodies. Diabetes, however, reduces the heart muscle’s metabolic adaptability and causes heart cells to overuse fat as a metabolic fuel.
The study, published in Circulation Research, found that this cardiac lipid overload leads to numerous small, misshapen mitochondria that don’t produce energy as efficiently as normal mitochondria. Previous research from the UI team has suggested that problems with mitochondrial energy production may play a role in heart failure associated with diabetes.
“Diabetes, which affects almost 30 million Americans, significantly increases the risk of heart failure, and one of the cardinal manifestations of the hearts of people with diabetes is the tendency to overuse fat as a metabolic fuel, which ultimately leads to mitochondrial and cardiac damage,” explains study leader E. Dale Abel, MD, PhD, professor and departmental executive officer of internal medicine at the UI Carver College of Medicine and director of the Fraternal Order of Eagles Diabetes Research Center at the UI.
“We have demonstrated and detected how increasing the amount of fat (lipid) that the heart consumes leads to dramatic changes in the structure and function of the mitochondria in the heart. These studies provide a new window into how these changes to mitochondria could occur in the lipid-overloaded heart.”
The findings suggest that cardiac lipid overload disrupts normal mitochondrial structure, which may impair energy production and compromise heart function.
Redefining Knowledge of Elderly People Throughout History
An archaeologist from The Australian National University (ANU) is set to redefine what we know about elderly people in cultures throughout history, and dispel the myth that most people didn’t live much past 40 prior to modern medicine.
Christine Cave, a PhD Scholar with the ANU School of Archaeology & Anthropology, has developed a new method for determining the age-of-death for skeletal remains based on how worn the teeth are.
Using her method, which she developed by analyzing the wear on teeth and comparing with living populations of comparable cultures, she examined the skeletal remains of three Anglo-Saxon English cemeteries for people buried between the years 475 and 625.
Her research determined that it was not uncommon for people to live to old age.
“People sometimes think that in those days if you lived to 40 that was about as good as it got. But that’s not true.
“For people living traditional lives without modern medicine or markets the most common age of death is about 70, and that is remarkably similar across all different cultures.”
Ms Cave said the myth has been built up due to deficiencies in the way older people are categorized in archaeological studies.
“Older people have been very much ignored in archaeological studies and part of the reason for that has been the inability to identify them,” she said.
“When you are determining the age of children you use developmental points like tooth eruption or the fusion of bones that all happen at a certain age.
“Once people are fully grown it becomes increasingly difficult to determine their age from skeletal remains, which is why most studies just have a highest age category of 40 plus or 45 plus.
“So effectively they don’t distinguish between a fit and healthy 40-year-old and a frail 95-year-old. It’s meaningless if you are trying to study elderly people.”
Cave said the new method will give archaeologists a more accurate view of past societies and what life was like for older people.
For those in the three cemeteries she studied, which were Greater Chesterford in Essex, Mill Hill in Kent, and Worthy Park in Hampshire, she found a marked difference in the way male and female people of old age were buried.
“Women were more likely to be given prominent burials if they died young, but were much less likely to be given one if they were old,” she said.
“The higher status men are generally buried with weapons, like a spear and a shield or occasionally a sword.
“Women were buried with jewellery, like brooches, beads and pins. This highlights their beauty which helps explain why most of the high-status burials for women were for those who were quite young.”
Cave’s study “Sex and the Elderly” was published in the Journal of Anthropological Archaeology.