Race, Genetics and Health

Uploaded by biosciEIU on 06.03.2012

[no dialogue].
[audience applause]
>> Dr. Benn-Torres: Alright, so I want to thank you
all for attending today, and for our organizers,
Dr. Mullen and colleagues for extending the very kind
invitation for me to come and share some of my research
and celebrate with you Darwin's 203rd birthday.
I would like to start today with a quote from a May 2002 article
published in the New York Times.
"In practicing medicine, I am not color blind.
I always take note of my patient's race,
so do many of my colleagues.
We do it because certain diseases and treatment
responses cluster by ethnicity.
Recognizing these patterns can help us to diagnose disease
more efficiently and prescribe medication more effectively.
When it comes to practicing medicine,
stereotyping often works."
This quote taken from an article entitled, "I am a Racially
Profiling Doctor," by Sally Satel, attest to how race may be
used in medical practice.
Underlying this racial profiling is the notion that beyond
skin color, there is some inherent biological differences
between race.
In these differences, furthermore, are the cause
of varying responses to some drugs and treatments.
Consequently to some physicians, using race as a proxy to learn
something about a patient, seems a reasonable choice.
However, the existence of biological race,
and by extension the use of race in biomedicine is directly
at odds with what most contemporary anthropologists
and human geneticists profess about human variation.
In today's talk, I want to share with you my thoughts,
inspired by my own work in molecular work in epidemiology,
as well as by the research of others in incorporating modern
anthropological explanations of human variation,
into epidemiology.
I suggest that the incorporation of a bio anthropological,
and bio cultural prospective on human variation
can significantly contribute to the understanding and
study of the distribution of disease.
This type of perspective utilizes a critical approach
to how human variation is understood within the context
of cultural constructions of race and its relationship
to health.
As we're all here to memorialize the great contribution that
Darwin made in articulating what has become the foundation
of modern biological science, the theory of evolution
by means of natural selection.
I would also like to recall Darwin's position on the origin
of meaning and human difference.
In the midst of a scientific, political, and economic
environment that sought to uphold notions of naturally
occurring, distinct, unequal human races, Darwin objected
and rather professed the unity of all humankind.
Darwin's position was in direct opposition to polygenesis
or the idea that each human race had separate origins.
Scientific racists use the concept of polygenesis as
evidence to justify institutionalized child slavery,
mass genocides and abuses of subjugated peoples.
Besides coming from a family of staunch abolitionists,
in his 1874 book, Dissent of Man, Darwin wrote of a unifying
factor, dissent from a single ancestor set of human beings.
Darwin was not denying the existence of human difference,
or race for that matter, but instead was trying to make
sense of these differences.
Years later we struggle with the meaning and value
of human difference.
We have all likely heard the factoid that in considering
DNA sequences, any two humans are 99.9% alike.
Now these estimates actually vary a little bit,
but the upshot is, that humans in general are all pretty
genetically similar.
So 99.9% alike.
What are we to make of this .1%?
Is this .1% responsible for variable responses to medicine,
is it responsible for variable in phenotype?
Is this .1% responsible for race?
The question in Darwin's time, just as it is in our time,
is not if there are human differences.
Our eyes and science clearly tell us that there are.
But rather, the question is, what is the best way
to describe this variation?
In the past, and to some degree today,
researchers have used the idea of race, where race is defined
as discreet, permanent and genetically homogenous groups,
to describe human variation.
Social and natural scientists have questioned this idea
of race by asking, for human beings, is race
a biological reality?
Is it a social reality or some mix of biology
and social factors?
Furthermore, what are appropriate ways for researchers
to approach the question of difference and disease
susceptibility and resistance across human groups.
As I'll explain today, possible solutions to these questions
may require a shift in the way human variation is understood
and studied.
This shift would require a move away from typological
categorization towards the use of another variable.
This variable, which I'll refer to as biographic ancestry,
more accurately estimates underlying variation,
as opposed to self identified race.
Secondly, we need a more critical and nuanced use
of race in biomedical settings than currently exists today.
So, the problem with race or the historical context
for this concept, it's really only within the latter half
of the 20th century that the majority of researchers in the
biological sciences have begun to accept that human races,
meaning exclusive homogenous and permanent groups,
has no basis in biology, but rather the social construction.
The idea that there is a biological basis to race
has a long history intertwined with political,
economic and social factors.
As such, the existence of a biological concept of race
has proved to be a very difficult concept to abandon.
Within the United States, the scientific history of race
is deeply entangle with the history of anthropology,
arguably since at least the 18th century,
anthropologists have been concerned with understanding
human difference.
Moreover, anthropologists have played critical roles
in creating and giving value to human biological differences.
Johann Friedrich Blumenbach, known as the father of physical
anthropology, is credited with creating the hierarchy that
persists within contemporary U.S. racial categorizations.
Influenced by his predecessor, Carolus Linnaeus,
Blumenbach organized humans into initially four,
then in later publications five groups, or using his own
terminology, five varieties.
In his 1795 publication entitled, "On the Natural
Variety of Mankind," Blumenbach categorized people into
Caucasian groups, American, Mongolian, Malay, and Ethiopian.
According to Blumenbach's system, Caucasian represented
the "ideal" type with all other human types as degenerations
of the particular variety.
As stated in his 1795 publication, Caucasian was
defined as the ideal race simply on Blumenbach's sense
of aesthetics.
"I have taken the name of this variety from Mount Caucuses,
both because its neighborhood and especially its southern
slope produces the most beautiful race of men,
I mean the Georgian, and because all physiological reasons
converge to this, in this region, if anywhere it seems
we ought, with the greatest probability, to place the
autochthones of mankind.
For in the first place that stock displays the most
beautiful form of the skull from which from a mean
and primeval type, the others diverged by most
ezeak predations on both sides.
White, we may fairly assume to have been the primitive color
of mankind."
After Blumenbach, certain prominent scientists throughout
the 19th century, worked to uphold Blumenbach's
racial taxonomy.
However, they questioned and ultimately professed a change
regarding human races.
In hindsight, this change appears to have been highly
influenced by political and economic climate of the day,
namely colonialism, and chattel slavery.
This change had to do with the origin of humankind.
According to Blumenbach and later Darwin for that matter,
humankind had a single origin or a monogenesis.
According to Blumenbach, human origin was among the people
of the Caucuses.
Scientists of the 19th century such as Samuel Morton,
Josiah Nott, George Lydia and Louis Agassiz were part
of the genetisist believing in separate origins for each
of the human races.
With separate races, it was not a far intellectual leap
to order these races into a hierarchy, which then could
justify inhumane treatment to "lower" races.
Though there were descendants to this and related ideas
about human races throughout the 19th century, it was not until
the mid-20th century in which there was a strong momentum
against the idea of a biological basis to race.
Prior to this period in the late 19th and early 20th centuries,
ideas about race move from classification and ranking
to a genetic explanation of a racial difference.
As a consequence, the eugenics movement in the United States
proved to be a very influential factor in shaping the notion
of biological races.
Despite the wide acceptance of biological human races,
some researchers during this period, notably Franz Boas
who is pictured here, also known as the father
of American anthropology, he challenged 19th century
ideals of classification and ranking through the use
of empirical data.
Based on analysis of anthropometric linguistic
and other cultural traits, Boas found that particular traits
defining racial groups were not concordant, meaning that
variation in one trait was not indicative of variation
of another trait.
Without concordant traits, it is not possible to define discreet
elusive groups.
In addition, as alluded to in his 1894 speech to the
American Association for the Advancement of Science,
Boas also found through his studies that there was more
variation within racial groups than between racial groups.
Boas's findings were later replicated by other researchers
such as Ashley Montagu, Frank Livingstone,
and Richard Lewington in the later half of the 20th century.
These conclusions have since become primary tenants
supporting the deconstruction of the biological concept of race.
In general, contemporary anthropologists convey that
upon examination of human genetic variation,
the taxonomic definition of subspecies or biological race
does not hold.
Though there are differences in gene frequencies between
populations, at local levels, such differences are not enough
to warrant a distinction between separate races.
Well what about more geographically distant groups,
can they be classified into races?
Well genetic studies based on global samples, show that for
[unclear dialogue] genetic distance is actually a function
of geographic distance, whereas geographic distance increases
so does genetic distance.
This distribution of genetic variation where
allele frequencies appear similar between geographically
close populations forms what is known as a cline.
Clines inherently contain no internal boundaries
and as applied to human populations, this means as
eloquently stated by Frank Livingstone in his 1962
publication, there are no races there are only Clines.
The American Association of Physical Anthropologist 1996
statement on race asserts that "they" meaning old racial
categories, "were often imbued with non-biological attributes
based on social constructions of race."
The statement also confirms that, "Humanity cannot be
classified into discreet geographic categories with
absolute boundaries."
As noted, the evidence supporting this statement
comes from a century's worth of investigation into the
description and the distribution of human variation.
However, despite the extensive evidence of race
as a biological fallacy, there's an emerging trend among
European scientists in which some researchers are revisiting
the notion of biological race.
This information comes from a 2009 study published
in the American Anthropologist entitled, "Current Views of
European Anthropologists on Race: Influence of Education
and Ideological Background."
An excerpt from this paper reads, "A dependence was sought
between the type of response, in this case it was response
to a survey that was about the existence of biological race
and several factors.
Three of these factors, country of academic education,
discipline, and age were found to be significant in
differentiating the replies.
Respondents educated in western Europe, physical anthropologist,
and middle aged persons, reject race more frequently
than respondants educated in eastern Europe.
People in other branches of science and those from both
younger and older generations."
The results from this paper indicate that a biological race
concept is still long from extinction within the sciences.
Biology and race in the 21st century.
As we enter the second decade in the 21st century, the issue
of race as a biologically meaningful concept has not
ceased to exist in evidence of this particular concept is ripe
among epidemiological studies.
As an example, a study released just last month,
which, incidentally, made many popular press headlines,
looked at the relationship between caffeine intake
and estrogen level.
The paper title, "Caffeinated beverage intake and reproductive
hormones among pre-menopausal women," concluded that for
Asian women, approximately two cups of coffee,
this is equivalent of about 200 milligrams of caffeine,
per day, resulted in increased estrogen levels compared
to other racial groups.
Whereas, the same amount of caffeine resulted in reduced
amounts of estrogen in white women.
No statistically significant result was observed in
African-American women.
The study goes on to note, that the source of caffeine
seemed to play an important role in which caffeine from green tea
or caffeinated soda resulted in higher estrogen levels
in all the included races.
In the end, the authors included that additional studies
are warranted in order to identify the relationship
between caffeine, caffeinated beverages and reproductive
hormones, and if there is a relationship on those by race.
A quick search of the literature will reveal a plethora of
similar studies that examine outcome based on race,
yet provide no or scanty evidence as to the nature
of difference between the recorded racial groups.
As a generalization in such studies,
there is no direct statement supporting the biological
concept of race, instead, there appears to be a presumption
and a lack of scientific holism.
In absence of an explanation for perceived racial differences,
many scientists tend to use cultural categories about race
that are already loaded with biological meaning.
The debate of how best to describe human variation
becomes more complex with the discovery of ancestry
and formative markers or aims.
Ancestry and formative markers, are genetic markers that have
allele frequencies that vary drastically between populations.
Aims are generally markers that are under selection
and thus the alleles appear very different as a function
of the environment they emerged under.
For example, a polymorphism in the FY gene is used as an aim.
This gene is responsible for the production of the
Duffy blood group.
This gene controls a glycoprotein receptor
on blood cells.
This receptor is normally used for cytokines that are used
during inflammation.
In addition, the receptor can also be used by plasmodium
vivax, a parasite that causes malaria.
For some individuals, they have a null allele,
meaning that they do not produce this receptor.
This lack of receptor confers a resistance
to malarial parasites.
Thus in places where malaria is endemic, there will be
a higher frequency of individuals that carry the null
allele, as opposed to places where there is no malaria.
As you can see on this map, the null allele is most common
among sub-Saharan Africans, where up to 98 to 100%
of the population carry the null allele.
And outside of Africa, where malaria is not endemic,
the null allele is very rarely expressed.
So markers that have a high frequency in some areas
of the world, and not as high in others, are considered aims.
So they have this frequency differential.
In this particular slide, I'm actually showing you
frequency differential for FY null.
So FY null is the absence of the marker.
As it's depicted here, this is actually the allele
that is a receptor but it's still based around this idea
of a null receptor.
So what we have here are basically some identification
information that's on chromosome one, Q23.2.
And the frequency of this particular allele
is very, very low in Africans.
So this is not the null receptor, it does say null,
but it's a variant of the null receptor that results
in an actual receptor, and you can see in non-African
populations, in Europeans and Native Americans,
it's at a high frequency.
So this is a great aim, or ancestry or formative marker
that's very rare in one group and common in another group.
So when we see it, we can make a probablamistic statement
that if you have this particular allele, there's a good chance
that you come from a non-African population.
What’s here, are basically the allele frequency differentials,
we call these delta values, and this is just a difference.
So, by using these aims, we're able to get an actual
estimate of someone’s ancestry.
Using a combination of many aims, some studies suggest
a minimum of 35 different aims, will allow for the estimation of
biogeographic ancestry.
More specifically, aims will be genotyped in a study population,
then the allele frequencies will be statistically compared
to a reference population.
Shared alleles between a study group and a reference group,
suggest shared ancestry.
Thus, genetic ancestry or biogeographic ancestry,
is an objective measurement that corresponds to biogeographic
region of origin where those with shared genetic alleles
have a shared origin.
Biogeographic ancestry has been utilized by anthropologist
to establish links between present and past populations,
as well as molecular epidemiologists in order
to map diseased genes.
Biogeographic ancestry, is distinct from race
in a number of ways.
Biogeographic ancestry is based on the genotyping
of particular alleles, which, due to frequency differentials,
can aid in identifying ancestral populations from broad
geographic regions.
Biogeographic ancestry does not contain the same social
and historical package as race, thus its definition is less
open to interpretation.
Additionally, biogeographic ancestry, assesses actual
genotypes, rendering it more useful than race as a biological
indicator of variation.
To illustrate this difference between biogeographic ancestry
and race, let's consider the results of my own genetic test.
Based on 109 aims, my ancestry is 89% African,
the 95% confidence level for that is 82-95%.
It's 4.7% Native American, with a confidence intervals
between 0 and 12%.
And 6% European, with confidence intervals between 1-13%.
So discounting Native American ancestry sets the confidence
interval includes zero.
My test results indicate that I have some non-African ancestry.
Despite this, I will self identify as African-American,
African-Caribbean, or the like, on the census reports or any
kind of demographic form.
My own example illustrates the point that ancestry and race
are two different concepts.
Once concept is based on laboratory results,
something that we can quantify, and the other has been part
of my socialization within the United States.
The distinction between genetic ancestry and race
is further illustrated when considering larger samples.
This table comes from a paper I published with a colleague
Dr. Rick Kittles, and is based on genetic ancestry as estimates
from people who self identify as European American, those samples
came from state college in Pennsylvania.
People who have self identified as African American, samples
were taken from Washington D.C., and Hispanic American.
These are groups of Puerto Ricans living in New York.
In the histogram, we can see that 98% of those that
self identify as European have upwards of 90% non-African,
presumably European, ancestry.
So that's this big red bar.
European Americans, upwards of 90% non-African ancestry.
Conversely, we look to this side, only 34% of those who
self identify as African American have over
90% African ancestry.
The general trend shown here, is that with an increase
in African ancestry, we can see that more people self identify
as African American, however, this leaves about 20%
self identified African Americans that have less than
60% African ancestry.
So it refers, this latter stat refers to the folks over here
all self identify as African American, but may have
very little African ancestry.
This trend suggests that for some people, self identified
race and ethnicity is not indicative of biogeographic
ancestry and thus self identified race and ethnicity
may not be indicative of underlying variation that may
play a role in treatment or disease.
There are limitations, however, in ancestry testing.
These caveats include identifying the appropriate
comparison populations, making sure that you have a sufficient
number of samples within your comparison groups and using
enough ancestry informative markers.
All of these features can have a significant impact
on the ancestry estimate.
So what are some other applications
of genetic ancestry.
In addition to learning more about recent population history,
biogeographic ancestry estimates are applicable to discerning
general population, genetic characteristics,
and have assisted in genome wide association studies.
In a recently published paper, my collaborators and I examine
the paternal lineages of 1300 African American men from
two regions in the US, from Washington D.C.
and South Carolina, and two regions in the Caribbean,
Jamaica and St. Thomas.
We found that many of the lineages of these men,
about 30-40% were attributed to gene flow from European men.
In addition, those men from South Carolina who did not have
European lineages had ancestry that traced populations found
within the grain coast while the non-European lineage of the men
from Washington D.C. and the Caribbean, generally traced to
populations in the Bite of Biafra.
These findings were in alignment with what is known
about the history of the Transatlantic Slave Trade,
and the subsequent arrival of Africans in the Americas.
Furthermore, our studies show that the presence of extensive
genetic heterogeneity, and population substructure
within African American populations.
Population substructure is the presence of subpopulations
within a larger group and it can be a result of recent add
mixture or non randomating followed by genetic drift.
Consequently within the United States, population substructure
is most commonly found among recently add mix groups like
African Americans and Hispanic populations.
The figure shown here depicts the problem of population
substructure in association analyses.
In the figure, we can see that both populations, one and two,
differ genetically.
Population two has a higher frequency
of the little A allele, and this results in each population
being disproportionately sampled in the case and control groups.
In this example we would find a significant difference between
cases and controls at it's locus that's a result of population
substructure, rather than an actual result due to the disease
or difference due to the disease.
To account for population stratification in an
association study, biogeographic ancestry should be considered
in the analysis.
This is done by first typing ancestry informative markers
across the genome, then using these genotypes to make
individual and locus specific add mixtures for each sample.
The add mixture estimates are then used as covariates
in the logistic regression analysis.
This is exactly what we did in the research collaborated on
about prostate cancer and again polar rectal cancer.
We employed biogeographic ancestry into our analyses
as we searched for candidate loci involved with the diseases.
Prostate cancer is one of the most common cancers affecting
men over the age of 65.
Age adjusted incidents rates for prostate cancer in all men
between 2004 and 2008 were about 156 per 100,000 men per year.
However, the incidents for African American males
specifically is much higher at 234 per 100,000 men per year,
compared to 150 per 100,000 European American men
and 129 per 100,000 Hispanic men per year.
Why this disease affects African American men is unknown.
Current research efforts are under way to understand both
the disease and the risk factors involved in disease onset.
In this prostate cancer study, we examine 24 markers
within a specific region of chromosome 8,
and 1,057 African American men.
The region of chromosome 8 had previously been shown
to have an association with prostate cancer.
In addition to genotyping the 24 markers, genetic ancestry
was also estimated for each participant based on 80 aims.
Besides illuminating a bit about the population history
of the sample, the biogeographic ancestry estimates were used
to correct for both global and local population substructure
within our association analysis.
The same methodology was applied to the
colal rectal cancer study.
Since the recognition that population substructure is
a potential co-founder, an increasing number of genome wide
studies are incorporating the use of genetic ancestry into
their analyses.
In addition to the use of aims to estimate biogeographic
ancestry in association studies, genetic ancestry tests have
also been commercialized by a number of direct to consumer
testing companies.
For a fee, these companies will send the client a
[unclear dialogue] swab to use for DNA collection
and return to the company.
The company will then test the sample for genetic ancestry
and produce a report that list, by percentage,
the biogeographic origins of the client.
This sort of test generally appeals to people interested in
using genetics to probe their own genealogy.
For the most part, the industry is unregulated and as such,
there is no standard for what and how much information
must be related to the client, nor is there a standard for how
the information should be interpreted.
This lack of regulation, in addition to lack of
interdisciplinary communication has led to the confusion
of genetic ancestry for a genetic definition of race.
In a recent edited book entitled, "Race and the Genetic
Revolution," Robert Polluck, a contributor, accuses the NIH of
promoting a research initiative to "examine human DNA for
evidence of race."
He goes on to note, "this NIH project goes on to find versions
of genes that are in everybody of one race or ancestry,"
he says, "this is a euphemism for race in this context which
are never found in the genome of people not in that race."
Though Polluck never specifies the initiative by name,
his accusation indicates the misinformation surrounding
the definition, purpose, and interpretation of biogeographic
ancestry and research.
The fact that this chapter is in a book published by
a well-established press, further indicates the potential
for the dissemination of this erroneous belief.
Despite the controversy and misinformation surround
biogeographic ancestry, it is an objective indicator
of biogeographic origins and as such can assess underlying
variation that can be informative about disease
disparity and resistance.
Consequently, it is well suited to address the question of how
best to describe human variation as opposed to race.
As a field that critically thinks about the nature
of similarities and differences in human populations,
anthropologists and related academic kin must be at the
forefront of ancestry at the race issue and use in research.
So genes, race, and health.
During the first decade of the new millennium, the use of race
in biomedical setting, was hotly debated by a number
of researchers representing a variety of fields such as
anthropology, medicine, and epidemiology.
Though many of the same themes scene with previous generations
were not as evident.
A refined use and application of more comprehensive genetic data
complicated the matter.
Proponents of the genetication of race could site
[unclear dialogue] or a 2005 article by Teng et al.
In the Teng et al study, Teng and colleagues observed
genotypic data based on 326 markers sampled from
US and Taiwanese participants, clustered into
four broad groups.
In addition, for the overwhelming majority,
self-identified race ethnicity of the participants
corresponded with one of the four genotypic clusters.
And this was with a .14 discrepancy rate.
For Teng and colleagues, race ethnicity proved to be a
valuable variable that was indicative of underlying
genetic variation.
Thus, ancient geographic ancestry which is highly
correlated with self identified race ethnicity, is a major
determinant of genetic structure in the U.S. population.
So in this picture, from Teng et al study, you see that
these are the four groups, so here, this group represents
the African Americans.
This group represents Asian Americans or the
Taiwanese population.
And this group represents Caucasians.
And you'll notice this known population here
that represents Hispanic groups.
A critique of this research cited problems
with the methodology.
Gravely in his 2009 paper for example, noted that with
a US population, Teng et al used a population from which
its members originate from geographically distant regions.
Thus, this critique summons one of the counter arguments
to biological race, and that's of clines.
Gravely essentially argued that what Teng et al actually
measured was different segments of a continuum and thereby
inserted boundaries in a line where there are none.
In addition another critique noted a problem of using
one group here represented as K, and calling that a cluster.
The camp of researchers that opposed the use of race
and biomedicine based their arguments on evidence
that indicates the biological fallacy of race.
Consequently, since race is culturally imposed, it cannot be
a useful variable to explain biologically based differences
to drug response or disease susceptibility.
Dr. Richard Cooper a cardiovascular epidemiologist
at Loyola University at Stricht School of Medicine,
and a long time opponent of race based medical decision making,
states the position clearly.
I'm sorry, I missed my slide.
What I'm trying to get your attention to is this blue pit.
Although the significance of race may be clear-cut
in many practical situations, an adequate theoretical construct
based on biological principles does not exist.
Anthropologist have in large measure, banned the biological
concept of race and its persistent widespread use
in epidemiology is a scientific anti-racism.
This extract taken from an article published in the
American Heart Journal in 1984.
Cooper's stance is in staunch opposition to other researchers
and professionals like that of Dr. Sally Satel whom I quoted
at the beginning of this seminar.
According to this side of the debate, the use of conventional
race categories provide some information medically relevant
information about a study participant.
Another outspoken proponent of the use of race in biomedicine
is epidemiologist Esteban Burchard, so the author
of the paper shown now.
He thinks of race as a variable that carries the potential to
extract information about environment genetic risk
factors, as well as information about the interaction between
risk factors.
He notes that despite the danger of collecting information that
may serve to essentialize or oversimplify human variation,
knowing the race and ethnicity of participants is outweighed
by the information that can be gained.
A third position on this debate, which is, now just
beginning to gain attention, conceives of race,
not as biological, but instead as a biocultural phenomenon.
Accordingly, race is not biology, but instead
influences biology.
Research by Clarence Gravlee on hypertension and skin color
among a sample of Puerto Ricans researched by James Collins
and Richard David on pre-term birth and social stress,
are both examples of studies that increasingly indicate that,
though, race is not biology, there are mechanisms in which
race becomes biology.
This mechanism involves that embodiment
of psychosocial stress.
In this case, the persistently negative experiences of racism
to the point where there is biological manifestation
of this stress.
Another epidemiologist Carl Phillips Jones, has suggested
a related model, in which three forms of racism,
institutionized, personally mediated, internalized racism,
all work to influence health.
According to Jones' model, additional access to resources
and opportunities, she calls that institutionalized racism,
prejudice, and discrimination, personally mediated racism,
and low self-worth, internalized racism, all work together
to essentially spoil the environment so that the affected
individuals cannot thrive.
While it may be of no surprise that stress can cause illness,
what is novel about this sort of research, is that there is
an attempt to incorporate a biocultural perspective on the
distribution of disease.
With anthropology, there is a research position
of applying a holistic approach to the study question.
I suggest, that with the coordination of social
scientists, a similar approach can be widely applied in
epidemiology studies.
Using this or similar models to what I've described in
combination with genetic characteristics such as
biogeographic history, may work better to address the questions
about diseases disparity across populations.
With regard to the place of race within epidemiology,
race should not be uncritically applied with biomedical studies.
Race is not a biological explanation for difference
among human groups.
However, there is increasing evidence that the stress and
other negative effects of racism are influential on health.
With only a focus on disease differences on races, as though
there were some underlying biological dissimilarities
characterizing race, researchers may well miss out on the actual
biological causes of disease disparity.
Interdisciplinary communication between social and natural
scientists will be one solution that may help to shift the way
that human variation is considered, in light of disease.
Race, as a biological paradigm, is not applicable to humans due
to incongruence with observed patterns of human variation.
Historical and social factors, further complicate
its application.
Many researchers interested in understanding how genetic
variation influences disease, are turning to
biogeographic ancestry.
Biogeographic ancestry is devoid of the social subtext that
hinders race and is a better way to assess genetic variation.
Thus, biogeographic ancestry may be a better way to describe
human biological difference and explore genetic causes
of disease.
Where human genetic diversity relates to medicine and health,
stereotyping will not always work.
Good communication in several dimensions, including
educational settings, research settings, and popular culture,
will help to ensure that our understanding of human variation
will move past the problems of previous generations, and arrive
at solutions that maybe benefit to all people.
And with that, I'm done.
A special thanks to you all for listening to collaborators
and to the two people who have provided so much support for me.
Thank you.
[audience applause].
>> female speaker: We have a few minutes for questions.
So questions for Dr. Benn-Torres.
>> male speaker: Would you say that
using genetic markers would be a long term replacement for using
race to do studies, or work in conjunction with?
>> Dr. Benn-Torres: I would say work in conjunction with.
Because we live in the United States we're a very
race conscious society, and we have a history-involving race
which has resulted in differential access to resources
differential access to different environments.
In fact if you look on, I think it's one of the most
recent census maps, you'll see that in the US we are still
quite segregated in terms of where we live, geographically.
Because of that, you may actually see difference
in access to resources, different environments,
different access to foods, which may play a role
in influencing health.
So the variable of race from more of a social access
to resources sort of angle, is still going to be useful
in delineating differences between disease susceptibility.
However, the incorporation of genetic ancestry, or other
actual genetic markers that indicate biological differences
will also compliment what we know on top of social factors.
So it's this way of incorporating this idea that
humans live in a bio cultural matrix.
Yes our biology informs our well being, but so does
environment, your schooling, your access to medical care
and to good food.
So, ignoring one, in place of the other is not going to be
a good solution as well.
>> female speaker: Other questions?
>> Dr. Benn-Torres: Yes please.
>> female speaker: You made comments about
the commercialization of genetic testing and things like that.
So my question is, what would be a better route
if you're interested in getting that testing done?
>> Dr. Benn-Torres: I think there's nothing wrong
with doing the testing, it's quite interesting.
A lot of people have actually debated its utility, but I'm of
the mindset that if you know very little about your family,
your ancestry, for me personally, I come from lineages
that were systematically denied information about who they were,
where they came from.
Genetic ancestry provides a tool to look back into the past.
When the science of it is explained to you in the
grand scheme of things, you are actually not learning that
much about your past.
So you can learn about your maternal lineage, or your
paternal lineage, that's one person or two people,
out of your entire family tree.
So in the grand scheme of things it's not that much, however,
if you knew nothing before, where you came from,
how you got there, it's a lot.
So I'm not discounting direct to consumer genetic ancestry
testing, it's quite useful, but I would encourage you
to do your homework, figure out exactly what you're learning,
figure out the science of it, how a result should be
interpreted, and then from there you can make a decision
as to its value for you.
>> male speaker: Do you have any suggestions
on how to go about doing that research?
>> Dr. Benn-Torres: The short answer is that
it's going to depend on who you are.
If your family has been established in a place
and there's actual records, I would go both routes.
The records can actually compliment
the genetic information.
If the records don't exist then you need to sort of
research as to what company is going to have the appropriate
reference populations based on what you know
of your family history.
So there's a number of sort of competing ones out there.
Some of these companies try to market towards a specific
ethnic group or people that have a shared history,
so you might go that route.
But ultimately I would suggest, do your homework,
find out what these genetic ancestry tests are going
to tell you.
>> female speaker: Alright well thank you
very much Dr. Benn-Torres.
[audience applause].
[no dialogue]