Medical myths for the festive season

A new study published in the Christmas edition of the British Medical Journal looks at a number of holiday myths and evaluates medical research in each area to establish whether the myths are true, false or unproven.

Firstly, does sugar makes kids hyperactive? Apparently not, according to the authors Dr Rachel Vreeman and Dr Aaron Carroll, who report that at least 12 double-blinded randomised controlled trials have examined how children reacted to diets with different levels of sugar. None of the studies (even studies that looked specifically at children with attention deficit-hyperactivity disorder) could detect any differences in behaviour between children who had sugar and those who did not. So, regardless of what parents believe, sugar is not to blame for ‘out-of-control’ little ones.

Secondly, does the number of suicides increase over the holidays? Although the holidays can bring out the worst in people, with an increase in stress related to family dysfunction and exacerbation of loneliness, studies from around the globe show there is no evidence for a holiday peak in suicides.

Thirdly, are poinsettias toxic? With flowers and leaves of red, green and white, poinsettias are often used in holiday decorations. Dr Vreeman and Dr Carroll found that in the largest study of poinsettia toxicity to date (which involved an analysis of 849,575 plant exposures reported to the American Association of Poison Control Centres) none of the 22,793 poinsettia cases revealed significant poisoning; no one died from poinsettia exposure or ingestion, and over 96% did not require treatment in a health care facility. However, medical advice should be sought if any plant not intended for human consumption is eaten.

Another myth examined is whether our body heat is mostly lost through our heads. For decades mothers have been repeating advice to keep our heads covered as that’s where most of our body heat is lost – but in fact, this is not correct. It’s recommended that all parts of the body are kept warm when out in the cold, but no special attention is needed for the head.

We often hear that to avoid unwanted weight gain we need to avoid eating at night – but is this true? Just because obesity and eating more at night are associated, it doesn’t mean one causes the other! Basically, if you eat too much at any time of day you will put on weight – there is nothing special about the time of day you eat.

Finally – is there really a cure for a hangover? From aspirin and bananas to vegemite and water there are endless suggestions for curing a hangover. Unfortunately, there is no scientific evidence supporting any hangover cure, whether it be ‘hair of the dog’ or any other remedy. The most effective way to avoid a hangover is to consume alcohol only in moderation or not at all!

For a full copy of the paper, log in to the resource section of our website.


Vreeman RC, Carroll AE. Festive medical myths. British Medical Journal, 2008; 337: a2769.

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