From a BBC article:
A study of 1,552 volunteers revealed a low social status can accelerate the ageing process by about seven years.
At the womens' average age of 46, they found the difference between the telomere length of those classified as manual workers - correlating to women in the three lowest social groupings, and non-manual workers - the women in the highest three classes, was equivalent to seven biological years.
To check that this was not caused by genetic factors, the researchers looked at 17 pairs of identical female twins, who had begun life in the same socio-economic class but were currently in different social groups.
They found on average, the telomeres of the twin in the higher social class were significantly longer than those in the lower social group - the difference equated to about nine biological years.
This finding is consistent with other strange findings. For example Oscar winning directors live longer. Because all directors are financially well off, you can't attribute this to better healthcare.
Being successful seems to have a mysterious beneficial effect on the human body. So by sending your kids to a state school, maybe you aren't just ruining their career prospects, you're actually condemning them to an earlier death.