"... last year, Moshe Szyf, Michael Meaney and colleagues at McGill University in Montreal, Canada, showed that mothers could influence the way a rat's genes are expressed after it has been born. If a rat is not licked, groomed and nursed enough by its mother, chemical tags known as methyl groups are added to the DNA of a particular gene.
"The affected gene codes for the glucocorticoid receptor gene, expressed in the hippocampus of the brain. The gene helps mediate the animal's response to stress, and in poorly raised rats, the methylation damped down the gene's activity. Such pups produced higher levels of stress hormones and were less confident exploring new environments. The effect lasted for life (Nature Neuroscience, vol 7, p 847)."
Ouch, ouch, ouch...from the mother who deeply regrets handing first child over to day care (which can never be as responsive as a good parent), and sees forever the effects.
The rest of the article on the effect of food supplements on genes and behaviour makes good reading.