Nature, Nurture & Epigenomes
Friday, July 26, 2013
Epigenetics is the study of changes in gene activity that doesn't involve alterations in our DNA genetic code and are passed down to one or more successive generations.
This type of gene expression is controlled by cells called epigenomes that sit outside and on top of the genome. Each individual epigenetic structure tells our genes to switch on or off; to scream DNA/RNA messages, or to whisper them softly. The science term for this signaling effect is called transcription.
After sequencing the human genome, it became clear that genetic information alone was not enough to understand observable characteristics or traits (phenotypes) and it's also becoming clear that epigenetic mechanisms are associated with disease.
This new science shoots big holes in biological beliefs regarding lifestyle (nature versus nurture) and its effect on the DNA we pass on to future generations.
Following his last edition of Origin of Species in 1872, Charles Darwin spent the rest of his life searching for possible mechanisms that would communicate information from the environment to the genome. He acknowledged in Origins that there had to be two forces in evolution - natural selection and conditions of existence. Of the two, he strongly believed the latter (conditions) were more powerful.
Conditions of existence have strong predictive powers that have now been tested by epigenetic science, therefore giving Darwin’s conditions of existence a much needed second hearing. These conditions include nutritional status.
One of my favorite 1960s college arguments is somewhat naïve in the face of epigenetic science, which seems to be proof positive, for now, that both nature and nurture play equally significant roles in the genes and epigenes we pass on to successive generations.
There is also increasing evidence that epigenetics play a major role in one-carbon metabolism and the pathogenesis of mental and neurodegenerative disorders including Alzheimer’s, Parkinson’s and a number of degenerative eye diseases, particularly where nutrient deficiencies that include folic acid and vitamin B12 are concerned.
Our country's enormous obesity health burden is not only attributable to excessive intake of government supported nutrient-empty center-of-the-supermarket junk food, it’s now suggested there may be a predisposing environment-related epigenetic make-up concerning easy weight gain, fat deposition and the present out-of-control silent inflammation phenomena.
Cardiovascular disease is projected to hold its grim record as developing nations increase their wealth and become more dependent on Western diets. Since specific nutritional habits are important risk factors for CVD, it’s important to understand how nutrient-deficient diets convert a healthy cellular transcriptional program into a pathological one.
Epigenetic science shows that DNA-associated regulatory proteins and RNAs, together with chemical modifications of the DNA itself, determine which parts of the DNA chain are transcribed or silent in a given phase of a cell’s life.
As science evolves, it will be exciting to stay on the forefront of proteomics (the structure and function of specific proteins), epigenetics, and nutrigenomics because they all hold enormous potential for developing therapeutic breakthroughs in many areas of disease prevention.
Ellen Troyer, MT MA
Biosyntrx CEO/Chief Research Officer