Does sugar make kids hyperactive? and six other myths debunked

Does sugar make kids hyperactive? Do we lose most of our body heat through our head? Will eating at night make you fat? Do suicides increase over the holidays? Are poinsettias toxic? Hangovers cures, do they work?

These are some of the common myths that are fictitious, according to an article in the Christmas issue published on bmj.com.

Researchers from the Indiana University School of Medicine looked at six myths related to the holiday and winter seasons. The authors, Rachel Vreeman and Aaron Carroll, then analysed the evidence to find out if the myths were true or false.

While parents may be convinced that sugary drinks, sweets and chocolate make their children hyperactive at least 12 studies have shown that there is no evidence to support this belief. Yet parents are so convinced about this myth that when they think their children have been given a drink containing sugar (when it is actually sugar-free) they rate their children's behaviour as more hyperactive. In fact, the difference in behaviour is all in the parents' mind.

As the Christmas and New Year cold weather approaches many people start wearing hats because of the strongly held belief that we lose 40-45% of our body heat through our head. Not so, say the authors, who argue that there is nothing special about the head and heat loss and "if this were true, humans would be just as cold if they went without trousers as if they went without a hat". If it's cold outside it makes sense to wrap up warm but covering your head does not make a big difference.

Some people swear by the rule that if you don't eat at night you won't get fat. Hogwash say the authors. One Swedish study seemed, at first glance, to support this theory as obese women reported eating more at night than non-obese women. However, in reality the women were not just 'night eaters' but were generally eating more meals. The simple truth is that people put on weight because they consume more calories than they burn—there is no getting round this, say the authors.

The research also finds that suicides do not increase over the holidays, poinsettias are not toxic and that hangover cures do not work. The only way to avoid a hangover over Christmas is to drink in moderation or not at all!