Nutrigenomics, popular representations and the reification of "race"?

• Author: Caulfield, Timothy

1. Introduction

   The concept of "race" has long been controversial. Not only is it a profoundly socially divisive notion, its relevance to the biomedical research community remains contested. Few in the scientific community would claim that the centuries old, socially constructed categories of race--such as black, white, Asian--have true biological significance. The human species cannot be categorized along clear biological demarcations. Indeed, we humans are a remarkable genetically homogenous lot. And the more we learn about the subtle genetic variations that make each of us biologically unique, the more it seems that the social concept of "race" is a biological fiction. (1)

   That said, there are, no doubt, subtle and identifiable genetic differences between discrete populations based on geographic origin. Understanding these differences can facilitate genetic research and, ultimately, disease treatment and prevention. And an exploration of difference does not lead, inextricably, to social dilemmas. As noted by one scientist: "Depending on how we use this information, the potential exists to describe simultaneously our similarities and differences without reaffirming old prejudices." (2) But it is easy to slip from a discussion of genetic variation between populations to the use of the biologically crude and politically and historically complex notion of race. As such, researchers, clinicians and entities that provide genetic services to the public must be careful how they communicate genetic information.

   In this paper, I explore the concept of race in the context of the emerging field of nutrigenomics. It has been said that "the assumption of real genetic markers that distinguish one ethnic group from another is at the philosophical heart of nutrigenomics." (3) Given this perspective, might the marketing of nutrigenomic services and products facilitate the re-legitimization of race as a biological concept? (4)

2. Nutrigenomics, Genetics and Race

   The current value of nutrigenomic testing has been questioned by many, including the popular press, (5) some in the scientific community, (6) government agencies, (7) and non-governmental organizations. Despite this apprehension, some companies already market nutrigenomic tests directly to the public and more will likely follow. (8) The business strategy for these companies varies, but many already offer nutrigenomic testing to the public. As suggested on one company's website, the aim of testing is to provide "personalized health and nutrition recommendations based on an individual's diet, lifestyle and unique genetic profile." (9) The website for this company goes on to suggest that nutrigenomic testing will help the public develop a "gene-based road map to health." (10)

   As part of the marketing of nutrigenomic testing, it seems likely or even inevitable that race will be used, either explicitly or implicitly, as a marketing tool. (11) The scientific literature that surrounds nutrigenomics often refers to populations from "Africa, Asia, and Europe." (12) At least one genetic testing company, DNA Direct, already advertises on their website for testing based on ethnic risk. (13) This is because the genetic variations that may cause individuals to metabolize food differently can roughly correspond to the broad social categories of race. Most Northern Europeans, for instance, can drink milk while many from Southeast Asian cannot. (14) This kind of geographically based variation can be found in other areas of genetic research, such as pharmacogenomics. (15) Indeed, many of the emerging large-scale population studies are specifically designed to identify gene variations within and between sub-populations. (16) It is hoped that this research will lead to an understanding of how members of certain sub-populations may have genetic characteristics relevant to health; be it a predisposition to certain diseases, the capacity to respond more effectively to a certain pharmaceutical, or the ability to metabolize caffeine in a particular manner. (17)

   As many commentators note, however, it would be a mistake to conclude that the identification of relevant genetic variation between populations will provide evidence of true biological differences between "races". By "races," I mean the social categories that are largely built around visual phenotypes like skin colour and that have been used to define racial groups for centuries. The sub-populations with identified genetic variations relevant to health may fall under this broad social construct, but the genetic facts are invariably tremendously complex. First, many commentators have noted that the social category of race has little biological relevance. Allan Goodman notes as follows:

   [H]uman biological variation is continuous, complex and ever changing .... race is inherently unable to explain the complex and changing structure of human biological variation .... individuals will always fail to fit neatly into racial box. Moreover, the placement of an individual in a given box says little about his or her biology: the racial mean is meaningless. (18) Second, and perhaps more important for nutrigenomics, the social category of race is not even a good proxy for more biologically meaningful genotypic variation. Francis Collins notes this in his critique of the use of race in genetic research:

   A true understanding of disease risk requires a thorough examination of root causes. 'Race' and 'ethnicity' are poorly defined terms that serve as flawed surrogates for multiple environmental and genetic factors in disease causation, including ancestral geographic origins, socioeconomic status, education, and access to health care. (19) Even commentators who put more stock in the belief that genetic variation and some disease predispositions correspond, however roughly, to social notions of race concede that a "[d]issection of disparities among racial and ethnic groups is complicated by the strong correlation between the socioenvironmental and genetic factors that differentiate these groups, with few persons differentially classified." (20)

   Nevertheless, it is easy to slip into the use of race as a surrogate for genetics, particularly when much of the public health literature already uses the concept of race (for example, in the obesity literature (21)). The term has both cultural currency and a degree of academic legitimacy as a way to group populations. As such, when explaining how genetic variation occurs between populations, using already existing (albeit biologically questionable) categories is an understandable tendency. But this is often, if not always, a mistake. (22)

3. Popular Representation, Market Forces and Race

   The concern that the social construct of race will be legitimized through simplified messaging is heightened when one considers the...