Alzheimer’s Brought to New World by Conquistadors, Study Finds

As if the native peoples of Latin America didn’t suffer enough at the hands of the Spanish: a study from UC Santa Barbara concludes that conquistadors likely brought Alzheimer’s disease to what is now Colombia in the early 1600s.

As reported in New Scientist on November 19, 2015, researchers have long puzzled over the extraordinarily high incidence of early-onset Alzheimer’s in Yarumal, a town in the Colombian state of Antioquia. About 5,000 people in the immediate region carry a gene mutation for the disease, half of them receiving a diagnosis as early as age 45. Reporter Rowan Hooper writes that:

Locals call the disease La Bobera, “the foolishness”, and the village bears uncanny parallels with the fictional Macondo in Gabriel Garcia Marquez’s novel One Hundred Years of Solitude, where people suffer memory disorders and hallucinations. But while Yarumal’s “curse” is well known, no one knew how the mutation first appeared.

However, that mystery was unlocked in 2015 by researchers from UCSB and the University of Antioquia. Scientists collected blood samples from 102 people in Antioquia and sequenced their genomes. The results showed that roughly three-quarters of the people had a specific mutation for early-onset Alzheimer’s — E280A — which came from a common ancestor about 375 years ago, right when the Spanish invaded. According to New Scientist:

“Putting the genetic data and the historical records together, the assumption that the mutation was introduced by one Spanish conquistador is very likely,” says Rita Guerreiro, a geneticist at University College London. “I think it is fair to conclude from this study that the history of Yarumal and the history of E280A are one and the same.”

The article goes on to describe the agonizing decision that the researchers made not to tell their test subjects the results of the analysis. It makes for provocative reading.

If the scientists’ supposition is true, then it is indeed a tragedy: The actions of a single conquistador doomed generations to suffer an especially severe version of an already painful disease. As described in the New York Times, the victims in Yarumal are prone to violence and lose the power to live indepently early in their lives. .

When I brought my father to Peru to care for him there, I knew little about Alzheimer’s and dementia in South America. During his year and a half in Lima, I met a number of gerontologists, neurologists and professional caregivers, and I began to get a sense of how prevalent the disease is in the metropolitan area.

This news from New Scientist gives a historical focus to Alzheimer’s in the New World.

I wonder: Would we have had Alzheimer’s and other forms of dementia in Latin America today if the native people had defeated the conquistadors?

 

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