New research on the effects of day care – not all it seems

In the last month a report appeared in the Daily Mail entitled ‘Putting baby in nursery could raise its risk of heart disease because it sends levels of stress soaring‘. This conclusion is based on a report by Aric Sigman, a psychologist who has previously been attacked by Ben Goldacre for his bad science (see here). Sigman’s day care claims have come in for a blistering attack by Bishopblog ‘How to become a celebrity scientific expert’. It’s a great example of why we need to understand science – because it means we are less gullible.

In brief Sigman bases his conclusions on accepted research that has shown that children in day care have raised levels of the stress hormone cortisol. But he then assumes that such increased levels later have negative consequences. In fact some research suggests that increased cortisol levels may lead to reduced fearfulness, a positive consequence. And further, the link between cortisol and heart disease is based on studies of people over 65 so it is mistaken to assume that children with raised levels of cortisol are more at risk of heart disease. However, it’s a very appealing newspaper title and has led to lots of comments from parents on the ill effects of day care.

The moral of the story? Don’t believe all your read. Always ask questions.