Study: More Amerindian ancestry confers significant protection against onset of Alzheimer's

Abstract
Background: Alzheimer’s disease (AD) is the most common form of dementia worldwide, and bears remarkable evidence for a differential prevalence among continental populations. In this scenario, estimating ancestry proportions in recently admixed populations is a strategy that can help increasing knowledge about the genetic structure of this complex trait.

Aim/Methods: Our purpose was to assess mean ancestry estimates for the three main parental contributors to the Brazilian contingent (European, African and Amerindian) using a panel of 12 ancestry informative markers. Outpatients with the late-onset form of AD (n = 120) were compared for ancestry levels with non-cognitively impaired subjects (n = 412) in the Midwest Brazil, controlling for classic clinical, social and anthropometric risk factors.

Results: Our findings show a 3-fold greater genetic Amerindian content among control subjects compared to AD patients (p < 0.001).

Conclusion: Our results suggest that the allelic architecture of Native Americans can confer protection against the onset of the disease.


See how anti-Native American racism destroys... oh, I guess it doesn't work this time.

Amerindians, Hispanics, and Alcoholism

According to this study, two polymorphic alleles considered candidates for alcohol-related diseases are distributed very differently in an unmixed, indigenous Mexican group versus a sample of Mexican mestizos. This helps explain the high rate of alcoholism among Amerindians. 

Here are death rates (per 100,000) from alcoholic liver disease (CDC):

Amerindian 15.4
Hispanic 4.4
White 4.5
Black 3.4
Asian 1.0

Notice how, compared to whites, Hispanics do not have a problem with alcoholism despite having some Amerindian ancestry.

I'll keep a lookout for more examples (and correct me if I'm wrong) but it looks like American Hispanics overall are not a comparatively unhealthy group of people.