As the Alzheimer’s epidemic rages on and researchers look for ways to prevent the disease from ever starting, they are also working to desperately understand how and why the disease begins. One researcher studied a tribe in the Bolivian jungle to understand the effects of dementia throughout history – and had surprising results.
Learn more about his study and what this tribe can teach us about the development of Alzheimer’s and a potential ancient cure.
Alzheimer’s as a Modern Disease
Anthropologist Dr. Ben Trumble had just spent six weeks with indigenous men from the Tsimane people in the Bolivian jungle evaluating the effects of hunting on testosterone levels, when he received news that his uncle had been diagnosed with Alzheimer’s disease. Just a few short years later, his uncle stopped eating, speaking and eventually passed away from the disease.
The death of his uncle led Dr. Trumble to wonder if the Tsimane people suffered from Alzheimer’s like we do and if not, what can they teach us about treating and preventing the disease. He hoped that studying the Tsimane may shed more light into how dementia affected humans before antibiotics and mechanized farming ever occurred. “There is really no cure yet for Alzheimer’s,” Dr. Trumble said.“We have nothing that can undo the damage already done.”
The Tsimane are different from what researchers call “weird” (western, educated, industrialized, rich and democratic) people in a number of ways. They have the cleanest arteries of any people group ever studied, leading researchers to believe they may be immune to heart disease. Additionally, while they have a high infant mortality rate, once they reach adulthood, they live as long as anyone else, making it possible for brain health to be evaluated beyond the age of 90.
Pulling data from a previous study of the same group of people, Dr. Trumble found that:
Tsimane who had the ApoE4 gene, otherwise known as “the Alzheimer’s gene,” actually performed better on cognitive tests.
Americans who carry two copies of the gene are 10x more likely to develop dementia.
How Parasitic Infections Impact Alzheimer’s
After being infected with parasites himself, Dr. Trumble began to wonder about the role of parasites were in dementia prevention. “Getting parasitic infections gave me perspective,” he said. At least 70% of the Tsimane people are infected with parasites at any given time and anthropologists think this is most likely true of our ancestors. He wondered if the infections caused by the parasites could change the way genes act in our bodies, if the ApoE4 gene actually played a survival role in ancient times, defending the brain from pathogenic parasites and infections.
When he looked at the data, Dr. Trumble found that:
The Tsimane with infections were more likely to maintain cognitive fitness if they carried at least one copy of the ApoE4 gene. The people who avoided parasitic infection and had the ApoE4 gene experienced cognitive decline, just like people in industrialized countries today. “Humans co-evolved with a number of different parasites, but today, in our sedentary city life, we’ve removed those parasites from the mix,” remarked Dr. Trumble.
More research needs to be done before creating a drug that would mimic a parasitic infection and more data needs to be gathered before researchers can determine the rate of dementia among the Tsimane and how parasitic infections can affect cognitive health.
The clock is ticking, however, as the Tsimane become more industrialized, using canned food, cellphones and other modern life amenities that are beginning to seep into their culture.
“This may be our last chance to understand whether chronic conditions of aging like Alzheimer’s and cardiovascular disease have always impacted humanity, or whether they’re connected with industrialization,” Dr. Trumble said.
What do you think about his study? Is Alzheimer’s truly an modern disease? Share your thoughts with us in the comments below.