December 25, 2010

Nature vs Nurture: Why do I get so many cavities?

I am often told by my patients that they were “born with soft teeth”, and can’t do anything about their tooth decay. Another popular thought relayed to me by my patients is that, “I inherited my parents bad teeth”, or “My parents have dentures so I’m going to have them, sooner or later”. This is unfortunately the excuse I get right before they decide not to have their teeth restored. I used to think that all of those sayings were not true, but recent research may shed some light on what your parents actually contributed to your current general and possibly dental health, after all. I tell my patients that the best way to become obese is to have obese parents, because they taught you how to eat. The same is true if your parents had dentures, you may have a higher chance of having denture yourself, because your parents were the ones who taught you your current oral hygiene habits, as well.

In recent years, the complete human genome gene sequence has been charted. That means every gene in the human body has been found, and an outlining made of what makes humans different from the rest of God’s creation. For the most part, they haven’t found a specific gene for periodontal disease, or for dental tooth decay, but they are still looking. However, they are understanding more about epigenetics. Think of the gene sequence in genetics as an orchestra with individual instruments populating the different position within. Epigenetics would then be the myriad of different notes each instrument can play to create a particular song.  If your parents genes learned to play a certain epigenetic “song”, then that song may be passed onto you, at birth.

Examples of epigenetics are abundant throughout the current literature, and studies have shown that various behavior and health conditions are due to inherited epigenetic changes called “transgenerational epigenetic inheritance”. The transgeneration rate of decay in epigenetic marks is currently unknown although it is likely that these do change over the course of a lifetime. This research has implications for assessing disease risk and the responses to ecological stresses and also for understanding evolutionary dynamics.

So the next time I hear from one of my patients that they are blaming their parents for their health woes, I might just sympathize with them!