Is it the genes? The environment? Or both....

Watching Discovery Health this afternoon, I heard the following quote:

Genetics loads the gun, but environment pulls the trigger.

The show was about teenage obesity. A teenage boy was unusually big for his family - neither his parents nor siblings had weight problems. His problems were attributed to some genetic influence somewhere on the family tree. As the story went on, an expert on obesity made the statement that genetics contributes about 30% to the problem of obesity, while the environment (ie, what we eat, how much/little we exercise) contributes the remaining 70%. Which, of course, led to the quote above.

I couldn't help but make the connection between this and the question of the enviroment on autism. It has been said in various places that the recent rise in autism cannot be attributed to genetics alone (because of the relatively slow process that would be). The argument has also been made that thimerosal can't be the cause of autism, since not every child that received shots with thimerosal has become autistic. Obviously (at least to me), there must be a middle ground.

So many things have changed in the environment in which we live today. The widespread increase in obesity can be linked to some aspects of this change. But not everyone is affected.

If the gun isn't loaded, pulling the trigger doesn't matter.

I think that this is also the case with autism. Is it thimerosal? Maybe. Is it something else? Who knows? Is it something we can change? I guess that depends on what it is? Is it something that we would change if we could?

tagged as: Autism, Obesity, Genetics, Discovery Channel