Nutrigenomics: DNA tests will soon help you eat smarter

By Dick Pelletier

     Ever wonder if all your vitamins, cholesterol and blood pressure pills are really necessary? Just as genetic differences between individuals determine one’s susceptibility to disease, genes also determine the body's reaction to different nutrients in food and medicine.
    
     This pioneering field of how nutrition and genes interact and the implications for dietary modification is called "Nutrigenomics." As doctors and dieticians become more knowledgeable in this new field, they will be able to prescribe diets that exactly match individual genetic needs.
    
     A strong link between genes and food was evidenced recently when University of Wisconsin researchers knocked out a gene called SCD-1 from mice which created a foodie's dream – a mouse that couldn't get fat no matter how much of a high-fat diet it ate. Human equivalent of SCD-1 exists and might someday be harnessed to eliminate obesity.

     But this science isn’t limited just to weight; Nutrigenomics can also protect us from disease. While only 5% of colon cancer is linked to inherited genes, 95% is susceptible to food and the environment, which raises or lowers chances of getting this cancer. Heart disease, hypertension, and diabetes are also subject to gene differences which explain why people eating similar diets exhibit disparity in their propensity for getting these diseases.

     If you are among the lucky people whose cholesterol count doesn’t react to diet, you could scarf down Egg McMuffins to your hearts content – no harm, no foul. With a better understanding of your genetic makeup, you would no longer need to spend money on vitamin supplements that do nothing for you; you would only take the exact nutrients your body needs.
 

     How does that work? Consider what happens when we eat a meal. Until recently, many scientists thought food had basically one job: to metabolize and provide energy for the cell. Indeed, that is what happens to most dietary chemicals – but not all of them.
 

     Some food never gets metabolized; instead, it changes into molecules that bind to proteins which “turn on” certain genes that sometimes cause harm. A diet that’s out of balance, doctors say, will cause these genes to nudge us toward heart disease, cancer, obesity, or other sicknesses unless we employ a "gene-smart" diet.
 

     "Nutrigenomics is revolutionizing wellness and disease management," says Guy Miller of Galileo Laboratories, a nutrition-based biotech company. Some 2 billion people in the world suffer vitamin and mineral deficiencies that limit intellectual development and wreak havoc with immune systems.
 

     So how do you determine what diet is right for you? Today, your doctor can refer you to in-home tests costing $100 to $1,000 that scan a dozen or more genes, but experts suggest if possible, you should wait. By 2012, a complete genetic profile analyzing every gene in your body is expected to be available at around $100; and by 2017, it could drop to $10; cheap enough to justify routinely sequencing every baby’s genome at birth.
    

     How might our life change as this science develops? Nestlé Research Center's Martin Kussmann says, "One day, we will enter a restaurant, swipe our gene card and the waiter will provide a menu showing only food compatible with our genes." Go "magical future."

This article appeared in various print publications and on-line blogs. Comments always welcome.