Your Genes, Your Diet

Did you ever wonder why some people can gobble stacks of bacon day
after day, without high cholesterol levels to show for it, whereas others
seem to get clogged arteries just by looking at fatty foods?

General health guidelines encouraging a balanced diet full of
grains, fruits and vegetables are sufficient in helping the majority of
people prevent obesity and related diseases. But each of us is somewhat
biochemically distinct, woven out of singular genetic strands that
influence metabolism and other body functions.

And scientists from the hottest area of nutrition research—it's
celled nutrigenomics—are busy determining which specific dietary
approaches are best suited to the individual biochemical profiles
dictated by our genes. After all, we are what we eat, and foods can be
viewed as tasty chemical parcels.

Nutrigenomics aims to identify the effects that the nutrients in
your food have on the function and expression of the genes in your
body.

An outgrowth of the Human Genome Project, the field examines genes
that have already been established as markers for disease. Then it tests
how common mutations of those known genes can be encouraged or
discouraged to carry out their plans, so to speak, via the chemical
intervention of particular nutrients.

"With more personalized nutritional genomic information," says Jose
Ordovas, senior scientist and director of the Nutrition and Genomics
Laboratory at Tufts University, "we will be able to use diet as a primary
disease prevention tool, in a precise way."

The research sounds more like science fiction than actual fact: A
doctor swipes the inside of your cheek with a Q-tip, and after a quick
analysis, produces tailor-made dietary recommendations. It is this highly
personalized approach to nutrition that may spark the psychological
motivation people need to change dangerous eating patterns, Ordovas
says.

"When we give global dietary recommendations, people typically
don't adopt them. They think they apply to other people, but not to them.
It would be better to say, 'You have to take this because your genes say
so!'"

Ordovas' team is teasing apart genetic factors
contributing to obesity. He envisions a time when an overweight person
can be virtually guaranteed that if they follow a particular path they
will successfully lose weight and maintain their weight loss.

This much he can say so far. "Some people, for example, will be
told to concentrate on limiting certain kinds of fats, whereas others
will be told to reduce their total fat intake."

There's a lot of individual genetic variation that influences our
propensity to obesity and cardiovascular disease, the number one health
threat in the U.S. and Ordovas' main research focus. A lot of it revolves
around our imprinted reaction to the modern diet.

"Some people can accommodate the fact that our diet has changed
since ancestral times better than others," says Ordovas. Large-scale
population studies have revealed that some ethnic groups have genetic
mutations that particularly influence their response to diet. Hispanics
and Native Americans in the U.S., for example, are especially prone to
diabetes. For those at risk, a modified diet could prevent the expression
of the mutation that leads to the disorder.

Genes are not necessarily destiny. They are influenced by the
chemistry of what we consume. Ordovas expects that we will be benefiting
from practical applications of nutritional genomics by the year
2010.