The Amazon tribe with healthier brains

On May 26 2021, a study was published in the Journal of Gerontology Series A: Biological Sciences and Medical Sciences by a team of researchers who discovered that the people indigenous to the Bolivian Amazon (also known as Tsimane) experience reduced amounts of brain atrophy compared to people living in, say Europe or America.

Image Courtesy: NBC News

Brain atrophy means the loss of special cells in the brains called neurons. It also destroys the unique connections that help the cells communicate. This can cause many diseases that damage the brain, including stroke and Alzheimer's disease.

Even though the people in technologically advanced countries have access to modern medical care, they eat a diet containing a high fat and a large number of calories while being relatively inactive. In contrast, the Tsimane who barely have any access to health care but are extremely physically active and eat a high-quality diet that includes vegetables, fish and lean meat.

The researchers used 746 Tsimane adults between ages 40 to 94 as volunteers in their study. To get the needed brain scans, they arranged for transportation for the volunteers from their villages to the closest town with CT scanning equipment.

The researchers discovered that, while the Tsimane in the middle ages and old age have a 70% smaller brain when compared to their western counterparts while also having high levels of inflammation. This suggests that the Tsimane’s brains experience reduced amounts of brain atrophy as they age, which results in reduced risk of mental ailments. The inflammation while related to the atrophy, does not have a distinct effect on the Tsimane’s brains.

Researchers believe that the Tsimane's low cardiac risks might overshadow the infection-based inflammation risk. One possible reason for the Westerners inflammation is that it is generally associated with obesity causes whereas, in the Tsimane, it is driven by respiratory, digestive, and parasitic infections. Infectious diseases are after all the most common cause of death among the Tsimane.

"This study suggests that coronary atherosclerosis could be avoided if people adopted some elements of the Tsimane lifestyle, such as keeping their LDL cholesterol, blood pressure and blood sugar very low, not smoking and being physically active,"

said senior cardiology author Dr Gregory S. Thomas, LongBeach Memorial Medical Centre, USA.

"Most of the Tsimane are able to live their entire life without developing any coronary atherosclerosis. This has never been seen in any prior research. While difficult to achieve in the industrialized world, we can adopt some aspects of their lifestyle to potentially forestall a condition we thought would eventually effect almost all of us."