Serenely
full, the epicure would say, Fate cannot harm me, I have dined today. - Sydney
Smith, quoted in Lady Holland's Memoir.
We
imagine ourselves to be slaves of our senses ie, taste, smell or sight. We relish food that is tasty, smells
delicious, and appears delectable. However, what if you are told that behind
all those senses, there is a network of genes that determines what your body
can actually consume. Seems strange, but is quite true. These diet-related
genes are responsible for the way our body reacts to different kinds of food.
They are now being utilized, in nutrition science, to understand an
individual's risk of developing
chronic nutrient-related diseases such as
cardiovascular disease, diabetes or cancer.
Science
of Nutrigenomics
The
term, nutrigenomics, was introduced in the early twenty-first century with the
advent of data from the Human Genome Project. Research in nutrition science was
prevalent even before the term 'nutrigenomics' was coined. Ghai and others,
filed a patent in 1996, on the discovery of certain flavonoids (plant pigments)
in citrus peel. These flavonoids enhance expression of a gene, which is
involved in
fighting cancer in the human body. Another common example of
the gene-diet relationship is lactose intolerance. Lactose intolerance is due to a change in the lactase enzyme gene
that results in certain individuals being unable to digest milk proteins. This
gives rise to an inability to consume milk products, resulting in stomach
discomfort.
These examples give a fair idea of the effects of genes
on different nutrient-related diseases.
Nutrigenomics basically studies
the response of genes to dietary nutrients. A parallel branch, nutrigenetics,
studies the effect of different gene changes (deletions, gene modifications) on
nutrient metabolism. The example of lactose intolerance involves change in a
single gene. However, a chronic disease such as cancer involves changes in many
genes. A combination of changes, in certain genes, can be responsible for a
particular cancer. Information, on such gene or protein changes, can give us an
idea of the susceptibility of an individual to a certain condition. A
registered dietitian, with the help of gene information, can understand the
effects of nutrients on such changes. Hence, nutrigenetics and nutrigenomics
can aid in providing personalized nutrition advice to an individual.
Effect
of Food on Disease Risk
Based
on our innate dependence on food, modifying our diet to avoid the risk of
developing health conditions is significant. It also highlights the disease
variation in the human population based on our different diet choices.
Fundamentally, the human genome shows variations based on ethnic and racial
groups. Food habits also differ across
these diverse human groups. The risk of disease development is controlled by
such variation, in addition to other factors such as
environment and
lifestyle. Another basic aspect, controlling the pattern of gene
expression, is malnutrition. This has been observed in diabetes, where undernourished
pregnant women in rural India, give birth to underweight children. Later in
life, these children tend to develop diabetes when exposed to nutrient-rich
diets. The undernourished fetus, in an attempt to obtain as much nourishment
from the depleted maternal food supply, suppresses insulin that breaks down
sugars. In later years, the individual is unable to digest sugar and fat-rich
food.
Nutrigenomics
Testing
Companies
around the world are utilizing information from potential diet-related genes to
identify risks of developing potential diseases. Nutrigenomic tests utilize
saliva, stools, or hair of individuals to identify irregularities in
metabolism-related genes. The wide range of tests provides information on the
individual's genetic profile. Registered dietitians are equipped to analyze
this information. Based on the analyses, specific dietary regimens can be
initiated to tackle the conditions involved.
Negative
Aspects of Nutrigenomics
There
are downsides to this approach. Such analyses, while empowering the consumer
with personalized information, may be harmful if not discussed with their
medical specialist. Genetic information, while comprehensive for the current
period, may not provide complete information based on technical limitations. It
could result in the patient undergoing unnecessary treatments, which may
trigger other complications within the individual. This is a cause for concern
even in other countries like Canada, Australia and the USA. Hence, there should
be a collaborative network of medical specialists and registered dietitians to
guide the patient in their treatment decisions. Another aspect to be noted is
that personalized genetic and health information needs to be utilized only for
treatment purposes rather than for commercial purposes. This will prevent
insurance companies from restricting coverage to individuals at risk of chronic
diseases. Finally, genetic information can also limit the freedom of choice for
food since an individual will be informed of a personalized dietary plan.
The
Future of Nutrigenomics
The
science of nutrigenomics will take a while to become an integral part of our
medical regimen. With understanding and acceptance of the integration of
nutrition in healthcare, there will be a better chance of arresting the
progress of different diseases and a higher survival rate. As Socrates was once
quoted, "
One should eat to live, not live to eat."
Source: Medindia
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