|
|
|
 |
| |
Forum—Finding Foods That Agree With Our Genes
|
| |
Since the recent announcement of
completion of the rough draft of the sequence of the human genome, there has
been much speculation about how this information will change our understanding
of health and disease. This gene-mapping accomplishment, which started with the
landmark discovery of DNA in 1953, raises many questions about the value of
sequence data. After all, knowing the sequence of the genes in the body is
interesting, but it doesn't tell us what the genes do.
DNA scientists are striving to relate the sequence data to gene function. This
includes not only what the genes do, but also how they interact with each other
and the environment to control our body's responses to changes in the
environment and diet.
This knowledge will come about through functional genomics, the science of
understanding the organization of genetic pathways and the expression of genes.
Genes produce mRNA, which directs synthesis of proteins. Studying cell type and
the conditions under which specific genes are activated to produce a specific
protein will lead to describing roles for genes in response to environmental
and dietary stimuli. The modern study of the cellular function of proteins has
been labeled "proteomics." Proteomics and functional genomics will
become a larger part of the human nutrition program in
ARS.
What does all of this have to do with foods we eat? A lot.
Certain variants of genes predispose us to respond to nutrients in a particular
way. For example, some of us are predisposed to cardiovascular disease (see
"Attacking
Heart Disease at Its Genetic Base," Agricultural Research, July
1999, pp. 20-21) or chronic diseases, like obesity, certain cancers, cataracts,
and diabetes.
Other people may have difficulty absorbing and using nutrients. The story on
page 12 in this issue of Agricultural Research provides new evidence
that given the exact same amount of a nutrient, each of our bodies might use
the nutrient differently. In this study the nutrient administered was
beta-carotene, and some people absorbed more of it than others and converted
more of it to vitamin A.
In the first half of the 20th century, human nutrition research focused on
studying nutritional deficiencies and inadequate diets. Later the emphasis
switched to the role of phytochemicals and other nonclassical nutrients. Many
of these phytochemicals are thought to prevent or reduce risk for certain
chronic diseases. For those diseases strongly linked to diet, the costs for
treatment and care exceed $200 billion per year.
One goal of future research will be to describe the role of particular genes
that predispose people to diseases as a result of a specific food consumption
pattern. Very little is known about how nutrient intakes, genotypes, and living
environments interact to affect individual health. There are, however, known
genetic defects that interfere with normal nutrient action, such as in Menkes'
disease or Wilson's disease in which one has inadequate or excess copper
absorption, respectively. But more needs to be discovered about other
gene-nutrient interactions that play a key role in our health.
Today we're trying to refine the recommended dietary intakes (RDIs) for copper
and other micronutrients to ensure that Americans of all ages get enough of
these nutrients (see the article on page 8 of this issue). ARS scientists are
among the prominent experts nationally who have been selected to help establish
RDIs for these nutrients. Ideally, genetic factors that affect an individual's
uptake and use of essential nutrients could be taken into account in RDIs of
the future.
New and innovative genetic information will advance the science of human
nutrition. This information will not only aid those who have known genetic
defects, but will just as importantly help those with common variants of genes.
One day, individuals may be able to tailor their diet to their genetic
constitution to reduce the risk of chronic disease.
Our past and our future are in our genes. ARS human nutrition research will
help us to extend our life and be healthier by identifying foods that agree
with our genes.
Kathleen C. Ellwood
ARS National Program Leader
Human Nutrition
Beltsville, Maryland |
|
"Forum" was published in the
March 2001
issue of Agricultural Research magazine.
|
|
|
[Top]
|
|
|
|
|
Last Modified: 05/18/2009
|
|
Share/Bookmark
Printable Version
E-mail this page
