Planning Your Meals to Save Your Life: Nutrigenomics

By Sarah Van Dalsem

Janos Zempleni
Dr. Janos Zempleni

Imagine the day when you'll find out the diseases you may get in your lifetime - and the foods you can eat to prevent them.

"Prevention of disease - that's what we're trying to do - as opposed to curing disease, which is much more expensive and, of course, comes with much more personal tragedy," said Janos Zempleni, Professor of Nutrition and Health Sciences at the University of Nebraska-Lincoln. Zempleni heads a UNL team called Nebraska Gateway for Nutrigenomics - one of just a few groups in the world focusing on such research.

"We really identify which genetic makeup predisposes you to increased disease risk and we identify dietary interventions that can be used to minimize the disease risk," he explained. Even though the study of nutrigenomics is relatively young, Zempleni and his team are beginning to solve mysteries such as why some people live long lives in spite of what they eat, while others aren't so lucky.

Members of the nutrigenomics team have individual specialties and study the interactions between nutrients and an individual's genes - how nutrients regulate gene expression, Zempleni said. As their work continues to unfold, people will learn whether they are at risk for a variety of diseases, as well as whether their children may be born with specific birth defects. Zempleni said the team includes about 30 faculty members from 12 different departments, both at UNL and at the University of Nebraska Medical Center. Team members specialize in plant science, animal science, food and nutritional science, biological sciences and biochemistry, among other specialties, as well as what Zempleni calls "hard core, bench-top scientists" working in genetics, ethnogenetics and gene regulation.

Most of the independent nutrigenomics researchers are funded by grants from three major organizations - the National Institute of Health, the National Science Foundation and the United States Department of Agriculture.

Understanding the Science

Zempleni said human genetic makeup is 99.9 percent identical, but that remaining one-tenth of one percent is what makes everyone different. That one-tenth of one percent can have major implications for nutrients, vitamins and disease risk.

For example, one specific gene in that one-tenth of one percent plays an important role in the metabolism of the vitamin folate, which is a B vitamin. If an individual carries a minor change - called a polymorphism - in this specific gene, it makes the protein produced by this gene much less stable, he explained, dramatically enhancing that individual's requirement for folate. Although most people consume adequate folate in the foods they eat, specific genetic testing will indicate who needs more folate.

"This change in the gene comes with increased risk of cardiovascular disease and also comes with increased risk of giving birth to children with birth defects such as spina bifida," Zempleni said, but "this little change in the gene can be easily characterized in the lab. The beauty about this is you can eliminate this enhanced disease risk by supplementing your diet with folate, so it's really kind of a change that is intriguing to know about and easy to address nutritionally."
At some point, it may be possible to have large-scale genetic testing for disease, Zempleni said, but not all disease risk will be related to nutrition. Additionally, some people will be predisposed to diseases that pose ethical dilemmas. For example, screening for psychiatric disorders or for cancer might limit an individual's eligibility for employability or insurance. For that reason, Zempleni said, "we really want to limit this to polymorphisms that are limited to nutrition simply because they can address this very easily by dietary intervention."

Zempleni and the people who work in his lab have pioneered an area of research demonstrating that biotin - a B vitamin - binds to certain proteins to articulate gene expression and DNA repair, he said. "The DNA aspects of this relates my research specifically to cancer and DNA repair," he said.

"I think UNL and Nebraska is uniquely positioned in that this is where most of the foods in the U.S. are produced. We have this critical mass of plant and animal breeders, we have the legislature behind us, we have agricultural business behind us. Of course, now with the advent of the Nebraska Innovation Campus, that really adds another layer of opportunity to our group," Zempleni said.

Increasingly, Zempleni expects that UNL Extension educators will be able to explain nutrigenomics to people who need the information, along with the role of a well-balanced diet in overall health.