Supposedly: Children with older fathers and grandfathers 'live longer' (http://news.ycombinator.com/item?id=4152379)
"Experts have known for some time that lifespan is linked to the length of structures known as telomeres that sit at the end of the chromosomes that house our genetic code, DNA. Generally, a shorter telomere length means a shorter life expectancy. ... However, scientists have discovered that in sperm, telomeres lengthen with age."