Study: Spending time in the sauna may combat weight gain associated with menopause

A new study in mice suggests that spending time in a warm environment, such as a saunacould help older adults, particularly women, combat age-related obesity and insulin resistance. Research indicates that heat treatments could be a simple and effective way to promote healthy aging.

In the study, older female mice were given daily 30-minute whole-body heat treatments. These mice gained less weight and showed improved utilization of insulin, which is essential for controlling blood sugar levels. The researchers also identified the biological processes responsible for these benefits.

“Women are more likely than men to become obese or overweight, especially after menopause “Due to the loss of estrogen,” said Soonkyu Chung, PhD, associate professor in the Department of Nutrition at the University of Massachusetts Amherst and lead researcher on the study. “Our study suggests that whole-body heat therapy could be an effective, noninvasive method to control weight gain and insulin resistance associated with menopause.”

The findings were presented by Rong Fan, a PhD candidate under Chung’s supervision, at NUTRITION 2024, the annual meeting of the American Society for Nutrition held in Chicago from June 29 to July 2.

“Heat therapy could be a practical option for those suffering from increased abdominal fat and an increased risk of metabolic diseases caused by hormonal changes during menopause,” Fan said. “It can be easily incorporated into routine health care practices through regular sauna sessions, hot baths or the use of specialized heat wraps.”

To mimic postmenopausal conditions, the ovaries of older female mice were removed. They were then fed a Western diet, containing 45 percent calories from fat, to induce weight gain. One group of mice received daily heat therapy for 30 minutes in a chamber at 40 degrees C (104 degrees F) for 12 weeks, while the other group received no heat treatment.

The results were promising. Mice that underwent heat therapy showed no tissue damage and had significantly lower levels of lactate dehydrogenase, an enzyme linked to tissue damage and aging. Heat treatment also effectively reduced weight gain induced by the high-fat diet.

Mice that received heat therapy showed significant improvements in insulin sensitivity and signaling. They also had less fat accumulation in critical areas like the liver and brown fat. Unlike regular fat that stores energy, brown fat is metabolically active and helps the body burn more energy. Previous research has shown that people tend to lose brown fat as they age, particularly during menopause, which contributes to a slower metabolism.

Benefits of heat therapy

The researchers also explored the molecular mechanisms behind the positive effects of heat therapy. They found that heat triggers several molecular processes that help the body use energy more efficiently and burn fat. One key protein involved is TRPV1, which acts as a calcium ion channel in the cell membrane. When activated by heat, TRPV1 initiates a process known as the calcium waste cycle, in which the body expends energy (in the form of ATP) to pump calcium ions across cell membranes. This process increases the amount of energy the body burns.

TRPV1 activation and the subsequent calcium cycle also promote fat breakdown and burning. This process reduces fat accumulation in tissues such as the liver and improves insulin sensitivity, which is vital for overall metabolic health. “These findings suggest that regular heat exposure can mimic the effects of calorie burning and fat loss,” Fan said. “This could be especially beneficial for people who find physical activity difficult, as it offers a relaxing way to improve metabolic health.”

Limitations of the study

Researchers stress that further research is needed to determine the optimal duration and intensity of heat exposure in humans. Further studies are needed to confirm the safety and efficacy of heat therapy in different populations.

Daily heat therapy may offer a new, noninvasive approach to managing age-related weight gain and insulin resistance, particularly for women after menopause.