New research designed to help consumers create customized diets based on their genetic make up will create ethical and legal challenges with serious implications for the scientific and medical communities, warns a new consultation paper by a panel of international experts.
The paper, "Nutrition and Genes: Science, Society and the Supermarket," a joint project of the University of Toronto Joint Centre for Bioethics (JCB) and the University of Guelph philosophy department, examines ethical questions surrounding the rapidly emerging field of nutritional genomics, also called nutrigenomics, the study of how nutrients and genes interact and how genetic variations can cause people to respond differently to food nutrients.
Research started in 2000 and is still in its infancy but scientists already predict it could bring about radical changes in how food is grown, processed and consumed. They believe it will not be long before the arrival of personalized diets tailored to genetic make up. A major target will be the baby boomers, reaching their 50s and 60s and trying to forestall the onset of age-related health problems such as heart disease, arthritis, menopausal hot flashes and bone-density loss.
But the paper's authors warn against a headlong rush to embrace nutritional genomics before there has been a detailed examination of its moral and ethical implications, backed by national awareness campaigns and public consultations.
The paper, prepared by a nine-member panel of international experts for presentation at the 2nd International Nutrigenomics Conference (Amsterdam Nov. 6-7), stops short of prescribing specific ethical guidelines for the development and implementation of nutritional genomics technology. Rather, it is designed to foster public debate, setting out issues that must be considered as consumers begin customizing diets to prevent and mitigate chronic health conditions.
The panel will collect input at www.geneticsethics.net from professional groups, citizens' organizations and individuals before issuing recommendations next year.
"This is a new model to get people's input before the science is fully rolled out," says JCB Director Peter Singer. "By addressing the ethical issues before nutrigenomic technologies reach the supermarket, we hope they can ultimately be introduced in the most ethical way.
"In future we may choose, for example, a breakfast cereal based on our genes," he added. "It is hypothetical today but possible that if you have a particular gene, you will be advised to use a cereal that decreases your chance of heart disease and avoid another that would increase your chance of colon cancer."
Science is uncovering more about the role of genetics in the development of diseases such as diabetes, obesity, cancer, heart disease, birth defects and food allergies, about how chemicals in foods can affect genes, and how genes can predict whether particular foods are likely to cause health problems.
Potential benefits of nutrigenomics research include improved individual health, greater consumer choice and control, greater disease prevention and related health care system savings, and greater social equity.
Genomic studies show some of the variation in such factors as blood pressure and bone density in people is genetically determined. In some people, food may cause genes to malfunction, which is why among people who consume the same diet, some do not suffer from a given disease, while others show elevated disease levels.
Environmental and lifestyle factors are thought to play a large role in the development of many diseases. Science has determined, however, that most people's genetic predisposition to cardiovascular disease is determined by variations in scores of genes, each of which appears to lead to small increases in susceptibility. As well, it appears that one gene can be involved in a number of conditions. Genetic testing may only be able indicate increased susceptibility to rather than certainty of future disease, the paper says.
Dietary advice today is based on observations at the level of large populations. However, advice that is good for the majority of people can be bad for a minority with different genetics, the paper says. There are estimates that dietary guidelines designed for entire populations give recommendations that might only work for two people out of three. The result is that many people are doing little more than taking educated guesses about their nutritional needs.
Nutrigenomics promises to enable people to reduce risks of developing diet-related diseases, and may be able to treat existing conditions. Personalized recommendations for food may be used as an adjunct, or in some cases possibly as a replacement for prescription drugs. However, the use of a genetically customized diet should not be seen as a rapid "cure" for diseases in the way an antibiotic can kill bacteria. It is more likely that adjustments to diets over a long time will strongly reduce the risks of a number of diseases and conditions.
The paper identifies as principal concerns:
- When is the science strong enough to market tests in a widespread way?
- Who should have access to nutritional genomics information, who should not, and how should improper access be prevented?
- How should nutritional genomics information be delivered to consumers?
- How can society prevent potential nutritional genomics-related inequities, especially those created between developed and developing countries?
- Which nutritional genomics concerns should be the subject of regulation and oversight?
Genetic tests on market
Some companies already offer dietary advice based on individual genetic profiles. However, genetic profiling is still in early days, and experts disagree on the ability of current knowledge to recommend useful dietary changes.
Tests to determine genetic risk profiles are currently being offered by a small number of companies in Canada, the United States and the United Kingdom. At least two companies say the tests will help people choose diets that will improve their health.
"In order to ensure that only the best science is available to the public, it may be helpful to establish scientific guidelines for the provision of such services, including clinical guidelines on the use of genetic tests for health care," says Dr. David Castle, a Professor with the University of Guelph philosophy department. "Guidelines could cover such factors as the nature of the test, the quality of research that it is based on, the value of the test for clients, its cost, acceptability, priority relative to other health care services and the results compared to using other means."
"If even part of its promise is realized, nutrigenomic testing and the labeling of foods for specific subpopulations on the basis of their genetic make up could become highly important public health tools," says Dr. Singer.
"But nutrigenomics research raises many of the ethical concerns now associated with genetic testing," he adds. "Most of these revolve around the central issue of how genetic information is managed."
Use of nutritional genomic-related information
"As more is learned about individual genetic susceptibility to disease, information from genetic tests may become increasingly attractive to outside parties who stand to gain from it," the paper says. "There is a concern that employers or insurers could use genetic information to the unfair disadvantage of some people. Two-thirds of respondents in a 1997 survey said they would not undergo genetic testing if they thought that health insurers and employers would have access to the results. As a result of concerns about potential misuse of information, a number of jurisdictions have enacted or are proposing 'genetic anti-discrimination legislation.' Some laws now prohibit insurers from requiring genetic tests or test information as a condition of insurance. At the same time, there is a widely recognized principle of insurance, especially in the private sector, that the insurer and the insured should have access to the same risk information."
Protecting the confidentiality of test results is very important because the predictive value of nutritional genomics testing is still very limited, and there is a high risk of misunderstanding the results. The identification of a genetic mutation does not mean someone will develop conditions correlated with the mutation, nor does the absence of a mutation mean that the person will not develop the conditions. Detailed predictions are years away.
There is an issue of whether private genetic information should be treated as confidential in nature and not communicated to others without consent. Personal medical information normally remain private but genetic tests may be relevant to blood relatives, so physicians may face cases in which they have to choose between patient confidentiality and providing potentially useful information to others in the same family.
Looking for food-gene interactions is mainly about disease prevention, so the sooner useful dietary changes are made the better the chances of avoiding related diseases. This suggests that testing children early would provide the widest range of health benefits. However, there is a balance to be maintained between acting in the interests of children before they are mature enough to make decisions and interfering with their right to confidentiality of genetic information. "This raises the question of whether the decision to administer a nutritional genomics test to a child falls within the legitimate range of parental discretion," says Dr. Castle.
So far, the results of nutritional genomics testing are not being stored in national biobanks and databases, but this could change. Some private databanks appear interested in obtaining this kind of information. One nutritional genomics company is already seeking consumer consent to sell information to pharmaceutical contract research organizations and health care companies for their discovery, development and trial processes. The fast pace of research makes it difficult to predict the future uses of this kind of information. This raises questions about how possible it is for individuals to give meaningful informed consent as it is traditionally understood.
Service Delivery Models
Though nutritional genomics research is still in its infancy, some companies have already put tests on the market, including predictive wellness or lifestyle tests. They are not advertised as being predictive for any specific disease, rather as useful for the promotion of healthy dietary choices. Another company offers a test for seven genes that influence the metabolism of certain nutrients and the elimination of toxins from the body. Another sells tests to identify a person's genetic risk for heart disease, stroke, hormone dysfunction, rapid bone loss and certain cancers.
The introduction and expansion of nutritional genetic services raises important questions about how these tests should be administered, by whom, and with what supports. The paper describes the pros and cons of four possible models: the consumer model, the health practitioner model, the blended model and the public health model.
Justice, Equity and Access
The emerging nutritional genetics market is being driven by a relatively small group of consumers who can afford to pay about US$400 for a test. There is a risk nutritional genomics will exacerbate a growing divide between those who have access to the fruits of genetic information and those who cannot afford it, enlarging already huge inequities in health status and disease burden both within developed nations, and especially between developed and developing countries.
If nutritional genomics testing turns out to be valuable for health care, there will be pressure on governments to fund the tests. As a general principle, the higher the predictive value of the nutrigenetic test, and the more effective known interventions are, the clearer the practitioner's duty to offer the test and society's obligation to fund it.
Regulation and oversight
Governments are looking at what if any regulations are needed to cover issues in this field, including scientific research, consent, counseling, testing technology and standards, who gets to provide nutritional genomics services, and access to nutritional genomics information.
Governments have a wide range of options. The most open would be to leave the issue to the market, as is now the case for home pregnancy testing kits or genetic testing to establish parentage. Moving up a step, governments could require or professional groups or the industry could unilaterally establish voluntary codes of practice. The most severe level of would be strict regulation, similar to that covering prescription drugs or HIV testing. This level might be applied only to testing that has a high potential psychological impact on a person or that requires extensive analysis or interpretation.
As nutritional genomics research zeroes in on more specific links between specific foods and diseases, the line between foods and drugs may become more blurred. This could pose challenges for governments, which have tended to regulate food and drugs differently. Governments are already grappling with what health benefits foods should be permitted to claim, and how these claims should be communicated to the public.
Because some of these "foods" make claims that enter the terrain traditionally limited to drugs, governments need to decide if and how they are going to regulate these products.
"The collection, storage and use of genetic information will be one of the most hotly debated medical issues of the coming decade," says Dr. Abdallah Daar, Director of the Program in Applied Ethics and Biotechnology at the JCB. "Even at this early stage, scientific progress is outstripping the public's ability to make informed choices about what kind of regulations should be introduced to address ethical and privacy concerns."
For more information: http://www.
University of Toronto Joint Centre for Bioethics Innovative. Interdisciplinary. International. Improving health care through bioethics.
The JCB is a partnership among the University of Toronto and nine hospitals. It provides leadership in bioethics research, education, and clinical activities. Its vision is to be a model of interdisciplinary collaboration in order to create new knowledge and improve practices with respect to bioethics. The JCB does not advocate positions on specific issues, although its individual members may do so.
The goals of the JCB are:
- To foster interdisciplinary research and scholarship, link education to research, and disseminate research findings to improve policies and practices.
- To support undergraduate, graduate and postgraduate educational programs in bioethics.
- To support clinical ethics activities including continuing education for health care providers, ethics committees, ethics consultation, and projects to address specific issues arising in JCB hospitals.
- To foster collegial discussion of bioethics issues throughout the JCB participating institutions, and to serve as a resource for the media, policymakers, and community groups.
The consultation paper can be previewed online starting Oct. 31 at http://www.