The prevalence of Alzheimer’s is increasing at a rapid rate. Researchers have been searching for ways to catch the disease early and even prevent it entirely. And the modern-day predicament has caused many to wonder: Is Alzheimer’s a modern disease?

Anthropologist Dr. Ben Trumble set out to get a better sense of the answer. He spent time with indigenous men from the Tsimane people in the Bolivian jungle to better understand the effects of dementia throughout history.

Specifically, Dr. Trumble sought to discover how dementia affected humans before antibiotics and mechanized farming were involved, according to Alzheimers.net, an online community for Alzheimer’s information and support.

Initially, Dr. Trumble discovered previous data showing Tsimane people with the Alzheimer’s gene – ApoE4 – performed better on cognitive tests. Meanwhile, Americans with two copies of the gene are 10-times more likely to develop dementia.

Parasitic Infections and Alzheimer’s

Spending time in the Bolivian jungle and becoming infected with parasites prompted Dr. Trumble to consider how parasites contribute to dementia prevention. About 70% of The Tsimane people are infected with parasites at any given time. Anthropologists believe this to be true of our ancestors, as well.

Dr. Tremble’s goal in exploring parasitic infections and Alzheimer’s was to determine if the infections could change the way our genes act. Specifically, he wondered if the ApoE4 gene actually worked to help people survive in ancient times, protecting the brain from pathogenic parasites and infections, according to Alzheimers.net.

The findings were quite profound. The Tsimane with parasitic infections were more likely to remain cognitively fit if they had at least one copy of the Alzheimer’s gene. Those without infection and with the Alzheimer’s gene, on the other hand, experienced cognitive decline – like people do in modern society.

“Humans co-evolved with a number of different parasites, but today, in our sedentary city life, we’ve removed those parasites from the mix,” he said.

Of course, more research is necessary before any action can be taken, like creating a drug to mimic parasitic infection. But time may be running short, as the Tsimane people become more and more exposed to industrialization, through canned food, cell phones and other amenities.

“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 are connected with industrialization,” Dr. Trumble said.