Race and Genetics

You might share almost all of your DNA with other people and still look different. That doesn’t make you of a different “race”, and here’s why…

Next Thursday, I’ll be mediating a discussion at school between a group of scholarship recipients and Dr. Dorothy Roberts. Dr. Roberts is the author of a book on race called “Fatal Invention: How Science, Politics, and Big Business Re-create Race in the Twenty-first Century“. Her major thesis in the book is that there is no such thing as “race” as we know it in the United States right now. There is no “Black” and “White” and “Hispanic” and “Asian” and such. She uses history and science to explain how race came into being as more of a social construct — a way of splitting people apart and keeping the undesirables away — than anything that is real. In short, race should not be treated as a biological trait.

As an epidemiologist and medical technologist, I’m very much aware of the different risks associated with being in different races. For example, Blacks in the United States are more likely to represent people with high blood pressure. In fact, the recommendation on sodium (salt) intake is different for Blacks than for Whites:

“However, if you are in the following population groups, you should consume no more than 1,500 mg of sodium per day, and meet the potassium recommendation (4,700 mg/day) with food.

  • You are 51 years of age or older.
  • You are African American.
  • You have high blood pressure.
  • You have diabetes.
  • You have chronic kidney disease.”

As far as Hispanics go (my people), our risk of diabetes is huge compared to other racial groups. Why is that? What genes are within our cells that increase this risk for us? According to Dr. Roberts, it may not be just genes. It can be a combination of factors… And I agree. Poor diets resulting from lack of access to fresh foods are more to blame for high blood pressure and diabetes (from obesity) than actual genetic predispositions. Why is it that my cousins in Mexico are lean and fit, without a hint of obesity? And why is it that I have gained so much weight? For starters, I don’t work in the fields and fast food restaurants dot my route to and from work and school. My cousins work in the fields or construction, walk to and from work (or ride the bus for a bit then walk), and they consume fresh foods that include a lot of fiber and not a lot of red meat.

Nevertheless, there is a lot of work being done at many academic and private locations to try and “unlock the secrets” of the human genome, and some of that work is trying to give race a biological basis again. And it is “again” because the eugenics and prior movements have tried in the past to tie race to genetics. (Dr. Roberts does a great job citing all her research, and it was eye-opening to read the footnotes and sources.) Companies are offering genetic testing and they offer, for an additional price in most cases, to “link” you to your “genetic ancestry”, a code name for “race”. So there is this very real tension between wanting to find those genetic differences that may increase our risk for certain diseases and not classifying people in groups because of it.

A perfect example of the tension in Dr. Roberts’ thesis was a question after a lecture she gave on her book¬†(50 minutes into the video). A man asks her about the genetic differences between races and uses sickle cell anemia as an example of the presence of these races. I had to shake my head because he obviously was out of his range in using that example. Dr. Roberts’ answer was splendid in explaining that there plenty of genetic differences between Africans, and that there are plenty of people in Africa who do not have the sickle cell trait. My response would have been to point out to him that sickle cell anemia is but one of many manifestations of genetic variations in how the body packages hemoglobin. Hemoglobin is the protein that transports oxygen from the lungs to the tissues and carbon dioxide from the cells to the lungs. Some people package the hemoglobin differently, changing the shape of their red blood cells, hence “sickle cell” disease. This mutation prevents infection with malaria parasites, and it is very common in people living in certain parts of Africa, but it is not a trait exclusive of Africans or, in this country, African Americans. Plenty of other people in other parts of the world have other hemoglobinopathies.

Sure, on the average and in the long run, if you have an anonymous vial of blood from a person in the United States, and you tested it, and you found it to have sickle cell trait (the mutation), you would be correct if you inferred that the person was African American (Black). But if you did the same thing in South Africa, you’d be out of luck to tell whose blood it was. Tell them over there that the blood is from an African, and they’ll laugh at you. And this is another thing that Dr. Roberts writes about: the difference in racial definitions here and abroad. In Brazil, she would be a completely different race than she is here, she writes.

That assertion touched a nerve with me. When I was living in Mexico, I was Mexican. I was not classified based on my ancestry at all. I’m a mutt. There’s a lot of European and Native American in me, but it was never anything to classify me in Mexico. There were plenty of Native Mexicans in the part where I grew up, and they were in their own social class, but they were still Hispanic. It wasn’t until I came to the United States that my race became important. When I applied to go to college, I had to check off a racial group in the application. I was confused. Was I “White” because I had European ancestry? Was I “Hispanic” because I spoke Spanish?

And it didn’t stop there. Plenty of people after college would ask me, “What are you?” I had to explain to them that I was born in Mexico, which immediately classified me as “Latino” or “Hispanic”. But I was different than the “Chicanos”, those of Mexican descent who don’t speak Spanish. I was different than the Cubans and the Puerto Ricans, though we were all “Hispanic”. I was certainly very different than the people from Spain, though we spoke Spanish. Then there was the issue of my last name. It’s a derivation of an Arabic word. So is there Arab in me? And is it Northern African Arab or Middle Eastern Arab… Did any of my ancestors live in Spain when it was conquered by Muslims?

I told you I was a mutt.

As a scientist, I am stuck in between this tension. On the one hand I have to acknowledge differences in outcomes between people of different “races”. On the other, there is no scientific basis for “race”, really, and trying to tie race to a biological marker makes studies done here (or in another ¬†part of the world) totally non-generalizable in other parts of the world. If I publish race-based studies here in the US, I’d be hard-pressed to try and replicate my findings — given the racial categories I may have assigned to people — in other parts of the world.

Dr. Roberts’ book is an easy read, and it is well-researched. If you’re a little bit into science and a little bit into social justice, you’ll enjoy it. It will certainly make you see genetic testing companies and “race-specific medicine” with a skeptical eye. And it will make you wonder if whether or not we’re making the same mistakes as eugenicists made back in the late 1800s and early 1900s by trying to find divisions among us, trying to put us in a bin.

  1. I hate to break it to you, but the eugenicists still are about.
    They still promulgate the same nonsensical things that have been discarded by modern science.

    As for “racial genetics”, there are uses in science for such data. Things like tracing the various migrations of humanity in the past is one use.
    But, as to the races of man, there is only one race, human.
    Well, there’s that other race, but none tend to favor it greatly, the rat race.

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    1. They’re still about but they’re not mainstream or accepted by modern science. At one time they were, though. That’s what is scary about current scientific works that once again try to put us into categories.

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  2. I’ve recently wasted time with a ubiquitous antivaccination crank who insisted that virgin-soil introductions of measles demonstrated the principle of happy “co-evolution” with infectious diseases (as Nature of course considers proper, because ME).

    It seems as though genetic homogeneity may play some role in this case, although the CFRs vary by an order of magnitude over different regions (the Pacific islands are best documented) and the whole thing goes hand in hand with geographic isolation and possible naivete to entire families of pathogens.

    Yet, it looks like HLA took a different route in east Asia before the first of the crossings to North America. This doesn’t even begin to salvage the pseudo-argument I was wasting time on, but *some* generalizablility distinct from the sickling allele might stand.

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