Nutrigenomics says you are what you eat

Melissa Southern, Dietitian, Jakarta, southerndietitian@yahoo.com

Have you ever known a person who seems to eat everything they want and never gains weight? Or someone who is overweight and smokes and lives to 100 years of age? On the other hand, there are individuals who follow all of their health care provider's recommendations, eat well and exercise daily but who still suffer from high cholesterol or heart disease.

Even though many of our health problems are generated from our lifestyles (smoking, overeating, lack of exercise, etc.), many others are simply due to our own individual makeup.

For many years now, scientists have sought to understand why some people react differently to treatments and recommendations than others. And the answer to that question is genetics.

Each individual possesses a unique set of genes and reacts differently to treatments or nutritional recommendations. The emerging field of nutrigenomics addresses just this problem. Nutrigenomics studies the way nutrition impacts your health through its effect on your genes.

The ultimate goal of nutrigenomics is to make individual nutrition recommendations based on your personalized genetic profile. Absolute and complete personalized nutrition advice would make generalized recommendations such as "eat less fat" or "get more exercise" obsolete.

Before going any further let me make clear that I am not talking about some long-term fantastical possibility.

Researchers involved in this field feel that within the next 10 years, nutrigenomics will be commonplace.

Many simple tests are already available now and the number of companies and scientists involved in the effort is growing daily. With that in mind, the purpose of this article is two-fold: first, to give you a preview of some of the latest and most fascinating research in the area of nutrition, and second, to warn you about the multiple new companies springing up that are taking advantage of this information.

The ideal use for genetic information in the field of nutrition would be to truly use food as a weapon against disease.

As a dietitian, I encourage my clients to realize that they truly "are what they eat" and that food choices can affect health in a negative or positive manner. Having detailed genetic information about an individual could take this concept even further.

Genetic information can be used to understand individual differences in diet-gene interactions and the ways in which specific diseases can be improved or worsened by your individual food choices.

One example of a genetic test that already exists is the lactose intolerance test. Ethnic groups including Africans, Latin Americans and many Asians cannot tolerate milk and certain milk products. In these individuals, consuming milk leads to gas, bloating and diarrhea. This problem is not due to lifestyle or environment, but rather to genetics.

Certain individuals who are lactose intolerant simply lack the genes that produce the enzymes necessary for the human body to digest milk. Currently, a simple test can indicate if an individual is lactose intolerant.

The next step in this process will be to develop tests that tell an individual exactly what to eat to prevent more serious problems such as high cholesterol, heart disease, obesity and a whole list of other chronic diseases.

It is not surprising that there is a great deal of interest and public acceptance of the concept of individualized nutrition. With public interest comes the opportunity for businesses to make a profit.

There are already many Internet companies promising individualized genetic testing and nutrition recommendations based on a blood or urine sample. Make sure that there is a sound scientific basis for the recommendations a company is making since most of these tests are not yet available for the public.

On a final note, it is important to remember that even though your individual genetic profile may be very important in determining dietary recommendations, lifestyle is important as well. The best example may be the Alaskan Eskimos. The traditional Eskimo diet includes a large amount of fish and blubber -- all high calorie, high fat foods.

Because of their previous active lifestyles, spending most of the day out in the extreme cold, Eskimos burned a very large number of calories and maintained very low rates of obesity and heart disease. Now that Eskimos have adopted more sedentary modern lifestyles, their traditional diets are causing an increase in diabetes, obesity and heart disease.

Individualized nutrition based on your genetic profile is just around the corner. In the meantime, be aware that your lifestyle habits still make a big difference and remember to watch out for companies trying to make a profit ahead of the research.