I don't get what you mean about the serving part. I don't think that those toxins would be significantly shortening to our lifespan. After all, 2 years is about 2.5% of the average lifespan (If you say it's 80 years old, that is. If you say 70 years old, then it's 2.9%), which is quite a lot. Furthermore, I don't think they'll be absorbed very well, and also, most lefties I know write with a curled hand position so that they don't smear the ink on their hands. Can't quite remember what they do, though. I'd say lefties live a shorter lifespan due to genetics.