For decades, it has been believed that genes are the foremost and final controller of our particular body shapes, personalities, and diseases. In fact, many scholars believed that the genetic code single-handedly decides one’s intelligence and is the cause of several global issues, such as poverty, crime and violence. However, revolutionary research in epigenetics — changes in organisms caused by modifications of gene expression rather than alterations of the genetic code itself — has yielded quite a different perspective. Environmental factors, namely one’s diet, behavior and surroundings, can “turn on or turn off” the expression of specific genes.
A groundbreaking experiment by Randy Jirtle and Robert Waterland on fat yellow mice (agouti mice) evidenced the phenomenon that certain changes to our diet can alter the expression of certain genes, without causing a single difference in the letters of one´s DNA.
Usually when agouti mice breed, the offspring are quite identical to the parent, just as fat and yellow and vulnerable to life-shortening diseases. Nonetheless, in an experiment conducted by Dr. Randy Jirtle and Dr. Robert Waterland, the parent mice produced a majority of offspring that appeared significantly different; the offspring were slender and brown and did not display their parents’ susceptibility to cancer and diabetes, and resultingly, lived to a relatively old age.
Instead of altering the genetic code of the mouse’s DNA, the researchers chose a surprisingly straightforward strategy. By simply feeding the mother a diet rich in methyl donors, beginning just before conception, Jirtle and Waterland virtually erased the effect of the agouti gene. Methyl donors are small chemical molecules that are capable of attaching to a gene and turning it off; they are found in onions, garlic, beets, and in the food supplements often given to pregnant women.
At first, it is reasonably surprising that how something as subtle as a nutritional change in the mother’s diet can have an unignorable impact on the offspring’s gene expression. What is even additionally surprising are discoveries proving that epigenetic changes can pass from one generation to the other and persist in the genome and echo far into the future.
This sheds significant responsibility upon us to maintain the quality and integrity of our genome: what we eat, smoke and what we are surrounded by does not merely affect our lives, but also that of the upcoming generations.
Many think DNA is the beginning and the end to our lives, that if cancer or diabetes are common in one’s family, one is ought to be afflicted with the diseases regardless of any efforts. However, advancement in epigenetics have introduced the idea of free will into the field of genetics.