Deep in the Bolivian Amazon exists a forager-horticultural community called the Tsimane. Researchers look to them for insights on how the human body functioned prior to modern technologies, as their lifestyles remain the closest to that of our ancestors. Oftentimes researchers find how we have navigated away from our evolutionary path, such as the Tsimane having the lowest rates of dementia , the healthiest hearts , and low late-age inflammation than those living in industrialized nations. But, new research from Arizona State University, has discovered a universal experience – post-menopausal women experiencing increased blood lipid levels, such as cholesterol.
Published today in the Evolution, Medicine, and Public Health, " Higher blood lipid levels after transition to menopause in two forager-horticulturalist populations ," looked at several blood lipids, like cholesterol, that are major contributing factors to heart disease. In industrialized nations, such as the United States and the United Kingdom, women notably experience an increased risk of heart disease post-menopause, including an increase in those blood lipids.
"While we have good data from industrialized populations, to our knowledge, nobody had looked at this relationship in a non-industrial, highly active population like the Tsimane before," explained Madeleine Getz, a PhD student studying global health in ASU's School of Human Evolution and Social Change , and lead author on the study.
The results of the study found that for the Tsimane, five of the six factors – including triglycerides, total cholesterol and low-density lipoprotein (LDL) cholesterol – were higher after menopause.
"While the difference varied by marker, they were between 1.5 to 11% higher after menopause. To see these risk factors increase after menopause in this population, despite their incredibly low levels of heart disease, was unexpected," Getz said, who is also an affiliated graduate student with ASU's Center for Evolution and Medicine and the Institute of Human Origins .
Despite this increase being two to seven times lower than those documented in populations in the U.S and the U.K., the marked increase in post-menopausal lipid biomarkers for the Tsimane makes for a similar pattern despite vastly different lifestyles and diets.
"This suggests that these increases in cholesterol around menopause may be a human universal, no matter how or where we live," Getz said.
Living a traditional hunter-farmer lifestyle, the Tsimane follow a diet free of processed foods and maintain high levels of physical activity, averaging around 15-20,000 steps per day. Their way of life closely mirrors that of early human societies, providing valuable insights into how modern environments influence disease and aging.
Benjamin Trumble, senior author on the study and professor in ASU's School of Human Evolution and Social Change, serves as the co-director of the Tsimane Health and Life History Project . The group has a longstanding relationship with the Tsimane to collect demographic and biomedical data, as well as helps to provide medical care for the community – a relationship that has been in effect for more than 20 years.
"Working with populations like the Tsimane allows us to global variation in both menopause, as well as human health and disease" said Trumble. "The findings here suggest that menopause is associated with increased risk factors for heart disease, even in the population with the healthiest hearts in the world. That suggests that post-menopausal increases in heart disease may be a human universal, and part of our underlying physiology regardless of lifestyle choices."
