Epigenetics and Positive Thinking

A few words about positive thinking and its effect on gene expression. Epigenetics means “outside of genetics.” Epigenetic phenomena are ones that change our gene expression. Changing gene expression is sometimes confused with changing genes. This confusion is exploited in popular scientific writing to promote the idea that we can change our genes. The main method by which gene expression is modified is through methylation of DNA which is a chemical process by which methyl groups are attached to certain points in the DNA. Specifically a hydrogen in cytosine (one of the four DNA bases) is replaced by a methyl group. The other three bases can also be methylated but cytosine is the main target for methylation. What methylation does is to suppress transcription at the point of methylation which means the corresponding genes are suppressed from being transcribed into protein. Almost all such methylation are transient. A few can stay around for a long period. But it is not known if methylation can be inherited. One important fact to note is that not all epigenetic modulation of the DNA are beneficial. Some methylation can cause diseases. Also note that methylation is not the only method behind epigenetics. There are other mechanisms that do not even touch the DNA and are even more transient. 

It would take a leap of faith to conclude that our willpower can change our genes. Medications and food we consume as well as stress can induce methylation and thus affect gene expression. Even losing a day of sleep can cause DNA methylation. But these are usually reversible. It is possible that positive thinking can affect gene expression and bring hormones into balance. But there is no evidential proof of causality.  Again, to be clear, controlling gene expression is not the same as controlling our genes. Positive thinking might seem to work in some cases. There are any number of people who will tell you that they cured their cancer through positive thinking that changed their genes or gene expression. Changing genes is not possible. But even for change in gene expression, it is hard to establish direct causality. But it can’t hurt to be positive as long as we maintain rationality. One can even speculate that the efficacy of positive thinking is also coded into our DNA. That is, there is a gene for positive thinking and there is another gene that regulates the effect of positive thinking on our hormones. It is very tempting to think that we can free ourselves from our genes but even the small probability of that happening may be coded into our genes! 

One of the insidious side effects of the promotion of positive thinking as a cure for our maladies is people blaming themselves for not being able to positively wish away their diseases. They read these books and hear anecdotes of various people who became cured through positive thinking. They then link their condition to their inability to think positively.  This could cause more stress and worsen their condition. Some people have called this the “tyranny of positive thinking.”