Epigenetics

NUTRITIONAL GENOMCS WHY DNA MAY NOT BE YOUR DESTINY http://www.google.com/imgres?imgurl=http%3A%2F%2F3.bp.blogspot.com%2F_207DNIaL-gc%2FTKzKXGrdt-I%2FAAAAAAAAASE%2FWHS4O7Sz8TI

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A Genomics Primer DNA: the double helix molecule of which genes are made

RNA: transcribes and translates the instructions from DNA

Nucleotides: subunits of DNA and RNA; aphosphate group, a 5-carbon sugar, and nitrogen-containing base. In DNA (A-T, C-G); in RNA (A-U,C-G)

Gene expression: the process by which a cell converts the genetic code into RNA and protein

Epigenetics: the study of heritable changes in gene function that occur without a change in the DNA sequence.

Is Genomics the Future?

Should our genes dictate what we eat? The new field of Nutritional Genomics suggest that lifestyle factors influence how nutrients gene activity and how genes influence the activity of nutrients.

The Human Genome Project was completed in 2003 that identified all of the genes in the human.

Genetic Variation and Disease

Variation in genomes of any two persons is about 0.1% which makes us unique and why in the same environment allows disease development in some people and not in others.

It explain why some of us respond to different dietary interventions, e.g. lowered saturated fat or sodium

It helps to explain conflicting results from research studies

The Agouti Mice Experiment (Epigenetics)

Both of these mice have the gene that tends to produce fat, yellow pup.

The mom of the brown mouse was fed B vitamins which silenced the gene.

The resulted in brown pups with norma appetite.

How Did This Occur?

The B vitamins acted as methyl donors; they caused methyl groups to attach more frequently to the agouti gene in utero, altering inhibiting its expression

Without altering the genomic structure, agouti moms were then able to produce healthy brown pups of normal weight and less prone to diabetes.

DNA Methylation

Some nutrients silence genes by providing methylation (adding a methyl group (CH); others activate genes by inhibiting methylation (less methylation.

Silencing or inhibiting depends on what the gene does; e.g. silencing a gene that stimulates cancer growth is beneficial; silencing a gene that suppresses cancer growth would be harmful.

DNA Methylation

Understanding of the human genome can change health care by:

Providing knowledge of a person’s genetic predisposition to specific diseases.

Provide a better understanding of the non-genetic factors that influence disease development (epigenetics)

Allow “designer” therapies (screening, behavior changes, medical and pharmaceutical interventions based on genetic profiles.