For years we have been taught that our genes are determined and that the diseases we develop are the result of bad genes. There seems to be nothing we can do but just accept our fate and hope someone finds a cure for the diseases we inherit. We have even taken a sort of perverse comfort in this, throwing up our hands and saying that it is not our fault. There is really nothing we could have done differently to avoid our diseases. But is this really comforting? Would it not be more comforting if we could affect our genes in such a way to prevent the development of disease?
Darwin introduced the idea that genes take millions of years to change based on natural selection. Genes are supposedly set in stone and produce whatever disease or beneficial trait that they encode and cannot be changed, at least by the inheritor. While we as Christians who believe in a Biblical creation do not accept Darwin’s millions-of-years idea, we have all been influenced by his thinking that the gene and gene product cannot be changed except by natural selection and changes in the gene pool.
However, scientists are discovering that while genes themselves do not seem to change, what a gene produces is highly influenceable so that even if you have certain genetic weaknesses or programming, given the right conditions, you do not have to express those genes. That is, certain genes seem to be able to be turned on or off based on our choices.
This field of research, called epigenetics, had its beginnings in northern Sweden where the winters are harsh and the growing season can be either extremely abundant or very bleak. The data collected from generations of families who lived here during these conditions has shown that abundance versus near starvation can turn on or off certain genes and lead to disease or early death in the grandchildren of those who experienced these conditions. A couple of examples: grandchildren of those who experience near starvation in childhood had more trouble with obesity and diabetes, grandchildren of those who experienced years of plenty and overate lived significantly shorter lives.
Another example of changing gene expression is that of agouti mice, born with a yellow coat and a genetic defect that results in obesity and diabetes. These mice while pregnant can be fed a special diet rich in B vitamins that turns their bad genes off so that their offspring, while born with the same genetic defect do not express it but instead are born brown, slender mice that have no weight problem or diabetes.
Even the genetic expression of brain function can be changed, it seems. Epigenetic studies have been done with mice that have a genetic memory problem. These mice have been exposed to an enriched environment with toys, games, and more stimulation and interaction, and their memories have shown some improvement. However their offspring, while having the same genetics, have displayed improved memory without any added stimulation which seems to be the result of the stimulation of their parents.
Data is also being collected on identical twins which have the same DNA and should also have the same epigenetic marks. However, scientists are finding that one twin will develop a genetic disease later in life and another will not. We still have much to learn but it seems possible that our individual choices in our own lifetime may turn on or off certain genes so that the gene expression of twins with the same genes diverge as they make different choices in life.
Our human genetic code, called DNA, is a set of code that consists of about 25,000 genes, mapped by the Human Genome Project. That code produces proteins that have certain functions in the body. Epigenetic marks are the marks above the DNA that tell it how to express that code. This is necessary since every cell has the same DNA code, yet each tissue expresses it in different ways so that we have a body with many functions and different parts such as skin cells, hair cells, brains cells, and hearts cells. We do not yet know the total number of epigenetic marks but it is estimated to be in the millions. Once complete, the Human Epigenome Project is predicted to make the Human Genome Project look “like homework that 15th century kids did with an abacus (1)”
In Time magazine’s article on Epigenetics, the author concludes that there is good news and bad news to these new findings. The bad news, he says, is that bad lifestyle choices can have bad effects on our children and grandchildren, while the good news is that epigenetic scientists will be working on drugs that can target these specific epigenetic marks to combat the problems we cause by our bad choices (1). Wow! Is it just me or is there something missing in this logic? When I read that I felt like there was an elephant in the room that no one wanted to acknowledge. While it surely is bad news that our offspring will suffer from our bad choices, what I see here is good news in that if we change our lifestyle and make good choices our offspring will benefit and perhaps we can eliminate entire diseases from future generations of our family tree by creating good lifestyle habits. Can you imagine how thankful our children and grandchildren would be to not struggle with the genetic predisposition to obesity, diabetes, some forms of heart disease, or certain genetically linked cancers? Once again, medicine and science continue to look for answers to our poor lifestyle choices not by changing our lifestyle but by inventing a drug so we can continue to make the same poor choices and not reap the same consequences. Well I don’t really think it is going to work. That is just too simplistic of an approach. With millions of epigenetic marks that affect our 25,000 genes why don’t we stop trying to find the magic pill and start making good lifestyle choices? I think it makes a lot more sense.
1. Cloud, John. “Why Your DNA Isn’t Your Destiny.” Time Magazine. Jan 6, 2010.
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