Thinking of getting one of those DNA testing kits? Aside from the Ancestry tests, the tests for your future health risks may be questionable and at this point you may want to save your money. Here is why.
A new outlook on genetics is called epigenetics and involves the concept of environmental factors (including diet) affecting how genes are expressed or inhibited. Thanks to this relatively new science, we now know that experiences of previous generations may show up in your health and well-being. Many of the risks for chronic diseases – including obesity, diabetes type 2, high blood pressure, heart disease and dementia can be traced back to your biological roots and the experiences your parent and even grandpaents had. Similarly, the food you eat may affect your children and grandchildren.
Is Your DNA Your Destiny?
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 itself
DNA Methylation: A chemical reaction that occurs in a cell when a methyl group attaches to DNA, changing the expression of the gene to which it is attached.
Methyl Group: A type of molecular structure that occurs in many compounds, CH3, for example.
Methyl Donor: Nutrients, like folate and vitamin B12 that when metabolized can donate methyl groups during the process.
To fully illustrate the epigenetic process, one must tell the story of the agouti gene.
The Result of Methylation
Methylation Effects in the DNA
Both these mice have the gene called the agouti gene that tends to produce fat, yellow pups, so we want to silence the expression of the gene if possible. There is a way. The mom of the brown mouse was fed B vitamins which silenced the gene. This produced brown pups with normal appetites resulting in a thin, healthy mouse.
Without altering the genomic structure, agouti moms were then able to produce healthy brown pups of normal weight and less prone to diseases. Even more surprising, when the offspring become mothers themselves, their babies can also be healthy, even without further vitamin supplementation. The yellow variant had been silenced, and that muted effect was inherited by the offspring.
How did this occur? Some nutrients silence genes by providing methylation (adding a methyl group (CH3); others activate genes by inhibiting methylation. It’s like throwing a wrench into the DNA to stop the expression of a gene or removing the wrench to allow the expression of the gene. The B vitamins acted as methyl donors that caused methyl groups to attach more frequently to the agouti gene in utero, inhibiting its expression. (See the black dots in the diagram above). Silence 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.
In any case, your lifestyle choices may play a role in your future health status.
It must be remembered that with any new concept, doubts and skepticism will occur. It must be recognized that we are not mice or lab rats, but the same effect has been shown by studying human interactions and is needed for more research to examine this interesting hypothesis. The implications are enormous in that we may be able to improve our health status by choosing healthy habits and lifestyles such as diet, exercise, stopping smoking, for example.
“The packaging of the gene may be as important as, or even more important than, the gene itself, and these epigenetic changes are predominantly influenced by environmental factors.” The Cancer Code, A Revolutionary New Understanding of a Medical Mystery Dr. Jason Fung, 2020.