Some of us have personal trainers, monogrammed towels, vanity license plates, or at least value our "personal" space, but are we ready for "personalized nutrition?"

Well, at least 130 delegates from 17 countries who attended the Second International Conference on Nutrigenomics in Amsterdam, The Netherlands in early November think we might be. A wealth of information about the role of genes in determining our health has become available with the deciphering of the human genome. The concept of "personalized nutrition," or "nutrigenomics" as some scientists call it, takes this information one step further. Personalized nutrition involves the establishment of individual dietary recommendations based on knowledge of nutritional requirements, nutritional status, and each person's unique genetic makeup to potentially reduce risk of disease. Many speakers emphasized that, although this new knowledge is very intriguing, we are still at early points on the learning curve despite the tremendous potential of nutrigenomics.

Shedding Light on the Science

According to Dr. Jose Ordovas of Tufts University, society has often embraced a "one-size-fits-all" approach to current dietary recommendations, such as low-fat and low-cholesterol diets for the entire population. Although this broad approach to recommendations will likely benefit the majority of people, research indicates that a number of complicated genetic factors may minimize the benefits of such dietary changes, potentially harm some individuals, or have no effect for some.

Different species, such as mice and humans, have particular genes in common; however, the genome, or an entire set of genes in a particular arrangement, is unique to each individual. Dr. Ben van Ommen, of TNO Nutrition and Food Research in The Netherlands, stated that it is now possible to determine the sequences of a whole genome and determine how the genes in that genome are expressed; rather than focus on one gene as a single datum point. "Nobody is equal, and neither are our genes, since every gene has at least ten variants," van Ommen said. He also emphasized that nutrition provides more subtle changes to gene expression than do pharmaceuticals.

Robert Kushner, MD, Medical Director of the Wellness Institute at the Northwestern Feinberg School of Medicine and Northwestern Memorial Hospital, shared his perspectives on how physicians may provide information on personalized nutrition to have better quality discussions with their patients. "Nutrigenomics has the potential to spark interest among physicians in seeing that nutritional needs are more clearly determined for individuals," Dr. Kushner stated.

Professor Michael Muller, of Wageningen University in the Netherlands, defined nutrigenomics as an attempt to study the genome-wide influences of nutrition by combining nutrition at the molecular level with genomics. He asked, is it possible that someday we might move from our broad-beam flashlight-approach to adopt more of a fine-tuned laser beam-approach to nutrition recommendations, making them very specific to an individual's needs?

Consumers Lead the Way

The conference featured an impressive array of scientific findings and experts showing great enthusiasm about future possibilities, but what do consumers think about all of this?

Unveiling highlights from a comprehensive, landmark survey of US consumer attitudes toward the broad area of genomics, including nutrigenomics, Christy White, principal of Cogent Research in Cambridge, Massachusetts, indicated that consumers are ready to learn more.

Three-fourths of Americans are interested in obtaining their personal genetic information to identify their risk of diseases like cancer, osteoporosis, and heart disease, and nearly half of Americans are prepared to use diet-related products tailored to their health needs on the basis of their genetic makeup, according to Cogent's October 2003 survey of 1,000 Americans. "Americans are ready and willing to buy products based upon their genetic information, but the science is only in the early stages of being able to deliver," said White. "The good news is consumers aren't looking for complete diet regimens, but for individual approaches and basic recommendations."

The survey reveals that more than 90 percent of Americans are aware of the connection between diet and health, and 71 percent believe that genetics play a crucial role in health throughout life. However, 73 percent are concerned about how personal genetic information would be stored and who would have access to that information (see "Examining the Ethical Issues of Nutrigenomics" below).

In October 2003, the US Senate unanimously passed the Genetic Privacy Bill, which would prevent health plans from providing access to insurance companies on the basis of genetic information and from using such information to underwrite policies. Employers would be allowed to collect genetic information only to determine overall workplace exposures but could not use the information in hiring. Although the Bush administration supports the bill, the House must still approve it.

Cogent Research also found that consumers most strongly preferred the term "personalized nutrition" with the term "nutrigenomics" being the least-liked term among the terms tested to describe this emerging area. Other terms tested included "nutrigenetics," "individualized nutrition," and "nutritional genomics." Cogent's conclusions on terminology are consistent with research that the International Food Information Council Foundation commissioned Cogent to conduct in December 2002. The findings of Cogent Research are from a broader, syndicated research study on genomics that explored applications including pharmaceuticals, health and beauty products, and nutrition. The study marks one of the largest efforts to understand consumers' acceptance of the use of their genetic information to influence the balance between health and disease.

What will it take to bring the promise of personalized nutrition to reality? Dr. Bruce German of the University of California at Davis painted the big picture for the delegates in Amsterdam. He sees this new knowledge as an opportunity to empower individuals to make informed and personal choices for their diet and lifestyle. According to German, "Scientists can enable the joys of life but not tell people what to do with their lives. We don't want to be the same—we want to be as healthy as we want to be. Success will involve personalizing health and delight simultaneously!"

Examining the Ethical Issues of Nutrigenomics

New research designed to help consumers create customized diets on the basis of their genetic make-up could create ethical and legal challenges with serious implications for the scientific and medical communities, according to a panel of international experts.

Dr. David Castle of the University of Guelph presented a paper in Amsterdam, 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, the study examines the ethical questions surrounding nutrigenomics, the study of how nutrients and genes interact, and how genetic variations can cause people to respond differently to food nutrients. Castle cautioned against a 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, 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 the issues that must be considered as consumers begin customizing diets to prevent and mitigate chronic health conditions. The panel wants input from professional groups, citizens' organizations, and individuals before it issues recommendations. which it will do in 2004.

Environmental and lifestyle factors are thought to play a large role in the development of many diseases. However, science has determined, for example, that most people's genetic predisposition to cardiovascular disease is dependent upon 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 be able only to indicate an increased susceptibility to cardiovascular disease, rather than the certainty of future disease, the paper says.

The paper identifies the following as principal concerns:

• When is the science strong enough to market genetic 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?

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 that they would not undergo genetic testing if they thought that health insurers and employers would have access to the results.

One of the most important issues is whether private genetic information should be treated as confidential in nature and not communicated to others without consent. Personal medical information usually remains private, but genetic tests may be relevant to blood relatives. Physicians may therefore face situations in which they must choose between patient confidentiality and providing potentially useful information to other members of the same family.

The main purpose of looking for food-gene interactions is to prevent or reduce the risk of disease; so the sooner useful dietary changes are made, the better the chances of avoiding nutrition-related diseases are. This suggests that testing children early would provide the widest range of health benefits. However, a balance must be maintained between acting in the interests of children before they are mature enough to make decisions and interfering with their right to the confidentiality of their 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.

"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 of JCB and director of the Program in Applied Ethics and Biotechnology. "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 go to the JCB Web site (http://www.utoronto.ca/jcb).