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By Arden Moore
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Have you ever wondered why you and a friend dutifully follow the same diet and your friend trims down but you don’t? Or are you puzzled by why your digestive system doesn’t tolerate spicy meatballs, but your spouse can eat them with ease? Have you developed high blood pressure despite eliminating salt from your diet?
“For as long as I can remember, we dietitians have always known that different foods affect different people differently,” says Libby Quigley, a registered dietitian for nearly three decades who directs a community nutrition program for Sodexho Health Care Division in Palm Desert. “In addition, we always knew there was a genetic component to diet, but didn’t have the science to truly substantiate it. Now we do, thanks to nutrigenomics.”
Nutrigenomics focuses on how specific foods and genes interact. This emerging gene-smart science investigates how to tailor diets to fit individuals’ genes. Lead-ing experts in nutrition and genetics are working together with a common goal: to someday deliver customized eating plans that take into account genetic makeup, lifestyle habits, and the environment for everyone of all ages and all locations.
The one-size-fits-all approach to dietary management is as obsolete and useless as an eight-track tape for your new SUV, say nutrition experts.
“We hope to be able to put what we call ‘personalized nutrition’ into the reach of everyone,” says Jose Ordovas, a senior scientist at Tufts University in Boston, Mass., in a profile on Tufts’ Web site. He is regarded as a world-renowned pioneer in the field of nutrigenomics. “We can use genetic tools to identify predispositions
to disease and tailor the proper recommendations — diet, physical activity, en-vironmental factors, even drug therapies — anything that can be controlled.”
Making Alterations
Ruth DeBusk, a geneticist and registered dietitian in Tallahassee, Fla., heads an international coalition determined to educate experts — as well as the general public —about the benefits of nutrigenomics on overall health and longevity.
“Genes represent the blueprint for who we are, but they are not a jail sentence. They are not set in stone,” says DeBusk, co-author with Yael Joffe of It’s Not Just Your Genes (BKDR Inc. Publishing, 2006) and author of Genetics: The Nutrition Connection (American Dietetic Association, 2003).
“Yes, the genes you inherit influence your health, but you can change the outcome and have greater control on how healthy you can be.”
Apparently, the public is listening. Accord-ing to a recent survey by the International Food Information Council, 71 percent of Americans favor the idea of using genetic information to provide individualized dietary recommendations. Ninety-four percent believe they have some control over their own health, and 69 percent state that food and nutrition play great roles in their health.
The Human Genome Project identified about 20,000 different genes. But genetic tweaking at the nutritional level is only in its infancy, reports Robert Pickard, director of the British Nutrition Foundation.
“We know the ‘addresses’ of genes,” he reported during an international conference in London. “Now we need to learn their ‘occupations’ and what influence certain foods have on modifying these genes.”
Choosing What Fits
Just because scientists don’t have all the answers yet doesn’t mean that consumers can’t benefit from what is known. There are about a half-dozen companies offering to analyze DNA to recommend customized diets. DeBusk undertook such a test, which involved having a sampling of her genes scrutinized.
A couple weeks later, and at a cost of about $250, she learned that she has a gene variance that makes her susceptible to heart disease. In response, she increased her intake of vitamin B- and folate-rich foods.
“When you learn what you are at risk for, it makes you pay more attention to what you eat,” says DeBusk, who at 58 considers herself to be healthy, thanks to regular exercise and a tailored diet. “Per-sonalized nutrition can’t promise that you will never get sick, but you can reduce your risk of disease by knowing your genetic susceptibilities and making the appropriate choices.” Her take-home message: You can tweak and improve your health at any age.
Quigley agrees, adding that one must also take into account their lifestyle habits and environment.
“At this point, we just don’t know how much of something is due to genetics, environment, or our habits,” she says. “This science of nutrigenomics is far too new and far too complicated right now, and we have far more questions than answers. Still, I am excited to be a dietitian at this time and to discover how much our genes play a role in our diet and our health.”
Chow Time
Researchers at leading commercial pet-food companies are identifying nutrients capable of “turning off” bad genes and “turning on” good genes in dogs. This manipulation at the cellular level may prevent or eliminate epilepsy, cancer, osteoarthritis, and a host of other canine health conditions.
Two companies, Hill’s Pet Nutrition and Nestlé Purina PetCare Co., have unveiled diets that incorporate nutrigenomics to deal with osteoarthritis, which affects about one in every five dogs.
Scientists identified a specific omega-3 fatty acid called EPA (eicosapentaenoic acid) that can “turn off” a degenerative enzyme that causes cartilage degradation. They shared their findings at an international nutritional conference in London and at a genetics conference in Sturbridge, Mass.
“As practitioners, we have known all along that arthritic dogs, when given EPA supplements orally, get better, but we never knew why,” says Jerold Bell, a clinical associate professor of genetics at Tufts University and director of the genetics conference. “Certain pet-food companies are researching different disorders and using modern molecular techniques to determine how components of food can impact the health of our pets.”
Nutrigenomic pet food is available only for dogs at this time. Major pet-food companies plan to begin research on cats, too. The dog genome project was completed prior to the cat genome project, which was finished in late 2005.
Learn More
Curious about how genes influence your diet? Following are additional resources to investigate:
Center of Excellence for Nutritional Genomics at University of California, Davis. nutrigenomics.ucdavis.edu.
This center provides the latest news and studies on diet and genetics and offers an online nutrigenomics course and community programs.
Human Nutrition Research Center on Aging at Tufts University, Boston, Mass. www.hnrc.tufts.edu.
This Web site offers articles on nutrigenomics research.
European Nutrigenomics Organisation. www.nugo.org.
This worldwide network of scientists is working to train a new generation of nutrigenomics scientists and to educate the public.
It’s Not Just Your Genes by Ruth DeBusk and Yael Joffe (BKDR Inc. Publishing, 2006).
Aimed at consumers, this book introduces the world of genomics.
Nutritional Genomics: Discovering the Path to Personalized Nutrition
by James Kaput and Raymond L. Rodriguez (Wiley Publishing, 2006). This book provides the basic principles and latest advances in nutrigenomics by leading experts in the field. |
