I was searching around the British Medical Journal for some material by Brian Deer, the investigative journalist who exposed Andrew Wakefield as the complete fraud that he is, when I stumbled upon an article entitled “Festive Medical Myths.” As the holiday season is almost upon us and we love busting myths here at SBL, I thought I would share the contents of the article with you here. You can find the source and study references at the bottom of the post.
The material below has been slightly edited for length, but appears mostly verbatim.
Festive Medical Myths
Myth: Sugar causes hyperactivity in children
Regardless of what parents might believe, however, sugar is not to blame for out of control little ones. At least 12 double-blind randomized controlled trials have examined how children react to diets containing different levels of sugar.
None of these studies, not even studies looking specifically at children with attention-deficit/hyperactivity disorder, could detect any differences in behaviour between the children who had sugar and those who did not.
This includes sugar from sweets, chocolate, and natural sources. Even in studies of those who were considered “sensitive” to sugar, children did not behave differently after eating sugar full or sugar-free diets.
Scientists have even studied how parents react to the sugar myth. When parents think their children have been given a drink containing sugar (even if it is really sugar-free), they rate their children’s behaviour as more hyperactive. The differences in the children’s behaviour were all in the parents’ minds.
Myth: Suicides increase over the holidays
Holidays can bring out the worst in us. The combined stresses of family dysfunction, exacerbations in loneliness, and more depression over the cold dark winter months are commonly thought to increase the number of suicides. While the holidays might, indeed, be a difficult time for some, there is no good scientific evidence to suggest a holiday peak in suicides.
In a study from the United States of suicides over a 35 year period, there was no increase before, during, or after holidays. Indeed, people might actually experience increased emotional and social support during holidays. In the US, rates of psychiatric visits decrease before Christmas and increase again afterwards.
Further debunking myths about suicide, people are not more likely to commit suicide during the dark winter months. Around the world, suicides peak in warmer months and are actually lowest in the winter.
Of course, none of this evidence suggests that suicides do not happen over the holidays. The epidemiological evidence just does not support that the holidays are a time of increased risk.
Myth: Poinsettia toxicity
With flowers and leaves of red, green, and white, poinsettias are widely used in holiday decorations. Even though public health officials have reported that poinsettias are safe, many continue to believe this is a poisonous plant.
In an analysis of 849, 575 plant exposures reported to the American Association of Poison Control Centers, none of the 22 793 cases involving poinsettia resulted in considerable poisoning. No one died from exposure to or ingestion of poinsettia, and most (96%) did not even require medical treatment.
In 92 of the cases, children ingested substantial quantities of poinsettias, but none needed medical treatment, and toxicologists concluded that poinsettia exposures and ingestions can be treated without referral to a healthcare facility.
Another study, looking at poinsettia ingestion by rats, could not find a toxic amount of poinsettia, even at amounts that would be the equivalent of 500-600 poinsettia leaves or nearly a kilogram of sap.
Myth: Excess heat loss in the hatless
Even the US Army Field manual for survival recommends covering your head in cold weather because “40 to 45 percent of body heat” is lost through the head. If this were true, humans would be just as cold if they went without trousers as if they went without a hat. But patently this is just not the case.
This myth probably originated with an old military study in which scientists put subjects in arctic survival suits (but no hats) and measured their heat loss in extremely cold temperatures. Because it was the only part of the subjects’ bodies that was exposed to the cold, they lost the most heat through their heads. Experts say, however, that had this experiment been performed with subjects wearing only swimsuits, they would not have lost more than 10% of their body heat through their heads. A more recent study confirms that there is nothing special about the head and heat loss.
Myth: Nocturnal feasting makes you fat
A common suggestion to avoid unwanted weight gain is to avoid eating at night, and at first glance, some scientific studies seem to support this. In a study of 83 obese and 94 non-obese women in Sweden, the obese women reported eating more meals, and their meals were shifted to the afternoon, evening, or night. But just because obesity and eating more meals at night are associated, it does not mean that one causes the other. People gain weight because they take in more calories overall than they burn up. The obese women were not just night eaters, they were also eating more meals, and taking in more calories makes you gain weight regardless of when calories are consumed.
Other studies found no link at all between eating at night and weight gain. In a study of 86 obese and 61 normal weight men, there were no differences in the timing of when they ate. Another study of 15 obese people found that the timing of meals did not change the circadian rhythm pattern of energy expenditure.
In a study of over 2500 patients, eating at night was not associated with weight gain, but eating more than three times a day was linked to being overweight or obese.
Myth: You can cure a hangover
From aspirin and bananas to Vegemite and water, internet searches present seemingly endless options for preventing or treating alcohol hangovers. Even medical experts offer suggestions.
No scientific evidence, however, supports any cure or effective prevention for alcohol hangovers. A systematic review of randomized trials evaluating medical interventions for preventing or treating hangovers found no effective interventions in either traditional or complementary medicine.
A hangover is caused by excess alcohol consumption. Thus, the most effective way to avoid a hangover is to consume alcohol only in moderation or not at all.
Conclusion
In the spirit of skepticism, the authors conclude:
Examining common medical myths reminds us to be aware of when evidence supports our advice, and when we operate based on unexamined beliefs…Only by investigation, discussion, and debate can we reveal the existence of such myths and move the field of medicine forward.
Source and Citation:
You can find the article online here.Vreeman, R.C. & Carroll, A.E. (2008) Festive medical myths. BMJ, 337. doi: 10.1136/bmj.a2769
According to the PubMed listing (which I believe the sugar and behavior part is taken from being that it is almost word for word what is stated here) … well – except for the last line which is conveniently missing here: “However, a small effect of sugar or effects on subsets of children cannot be ruled out.” – I looked because I have seen this effect on nieces and nephews … not just simple hyperactivity but they became ‘cranky’ (for lack of a better word). One nephew I discovered the hard way – should NEVER get orange juice. A reproducible effect.
Just wanted to add this since my experience told me a different story than the condescending tone here said … there are some children who react adversely to the substance … and the study quoted even says so.
This is the link to the what I found: http://www.ncbi.nlm.nih.gov/pubmed/7474248
Unfortunately, your anecdotal evidence is probably confirmation bias. When we expect an outcome, we remember all of the instances when kids seem hyper after ingesting sugar and forget all of the times when they do not, for example.
Anecdotal evidence is the least reliable form of evidence in science. There are so many flaws and biases to human cognition that we cannot trust ourselves to be reliable information gathering machines.
Any condescending tone you perceive is simply the interpretation of the existing evidence. It may subjectively seem that kids get hyperactive after having sugar, or even seem like common sense, but in science we have to test common sense. In this case common sense is wrong.
Pay attention to the conclusion of the article you referenced:
The meta-analytic synthesis of the studies to date found that sugar does not affect the behavior or cognitive performance of children. The strong belief of parents may be due to expectancy and common association [confirmation bias].
The last sentence that was omitted that you pointed out is not a cop-out, it is the duty of researchers to qualify their findings in the correct context. They are saying that it is not impossible that some kids may be affected, but all of the evidence so far shows that they are not.
Ah – yes … of course you would assume that I have no idea what confirmation bias is. Which is what I meant by condescending – you don’t disappoint. ;-)
This is why I paid attention to their behavior – and made sure it wasn’t just me seeing it when ever … but you know – I’m a stupid non-scientist who doesn’t understand such complex things.
I was going to come back with the possibility that it could be a sensitivity to something else besides the sugar as some allergic reactions to food dyes and such have been suspected in other areas (not with these kids – I’m talking about other things I have read) – but of course I find that I’ve been told my experience (without asking about any details – like if I had thought it might be bias) was just flat out wrong. Like you were there … and of course the “may not apply to all children” is just a ploy. Nice to know that one actually can admit the possibility … oh wait – you can’t because it’s just a CYA type of deal and according to you – doesn’t actually mean anything.
I appreciate your assumption that I need to be talked to like a grade school student. One of the things I’ve noticed with these studies is that they take place outside of the child’s normal surroundings … in a ‘controlled’ setting. Has anyone figured in the fact that children behave differently in an unusual setting than they do at home? I can’t tell you how many times I’d heard people say how well behaved a child was at a friends house when they are anything but that at home. Is this factored into these studies? Sugar changes body chemistry (insulin production etc) – but doesn’t effect anything else? What of behavioral changes with high and low blood sugars … there are a lot of things that aren’t answered by these little snippets one can find online.
I’m sorry that you took my comment as you did. I do not make assumptions about anyone’s level of scientific understanding. I have many foreign readers and my responses need to cater to everyone.
If you look at the actual studies themselves (you usually need a university affiliation or have to pay for them, sadly) you find that many of your concerns are indeed controlled for. For example, the experimental setting is applicable to the study of sugar and hyperactivity because the sugar is supposedly linked to the cognitive and behavioral markers of the hyperactivity itself (measurable variables). If there were a true effect, we would expect to see hyperactive children after they ate sugar in all situations and not just ones outside the lab.
If hyperactivity is not seen in the lab but is seen in less controlled settings, like your experience mentioned, it is more likely that sugar is not the variable causing hyperactivity (perhaps it is interacting with peers, etc.).
I appreciate your enthusiasm for science. Stay skeptical.
Are poinsettias toxic for dogs and cats? I somehow remember hearing this somewhere.
And you can cure a hangover. Just knock back a few more drinks in the morning. :-) On a more serious note, what is a hangover exactly? I know it is caused by drinking too much alcohol. But what triggers those hangover symptoms like nausea, headache, etc? Is it low blood sugar perhaps?
No, they are not poisonous to pets (I had to check for the sake of my cats).
I think most of the hangover symptoms are derivative from severe dehydration (from except urination).
Can you offer a citation for the claim tacit in the post that drinking water does not help mitigate hangovers?
You can find the review here.
Here is the conclusion (which includes water):
No compelling evidence exists to suggest that any conventional or complementary intervention is effective for preventing or treating alcohol hangover. The most effective way to avoid the symptoms of alcohol induced hangover is to practise abstinence or moderation.
I believe that the argument is that the detoxification of the alcohol in the blood via the liver is a process not positively affected by increased water intake. The rate is the rate.
I’m interested to delve further into the effects of sugar levels on mood. Do you know of any studies with other age ranges and that may include other states such as irritability, attention-span, problem-solving and those sorts of things? Or how people react under stress? I myself seem to be affected by my blood sugar, but I’m rarely hyperactive because of it. I might be an anomaly, tricking myself, or just monitoring a common effect more closely, I’d love to know which it was.
I’ll look into it and get back to you.
The study referenced here explains how levels of mood (positive/negative) can be modulated by blood sugar levels. The higher the blood sugar, the more positive the mood. Those with low blood sugar felt more tension in mood.
When preforming cognitive tasks, lower blood sugar also correlated with lower reported energy.
Keep in mind that the studies for mood included diabetic patients, so the effects are probably exacerbated for them.
No cure or prevention for hangovers besides not drinking alcohol? Does drinking water not count? Drinking lots of water sure makes a big difference for me.
Not according to the studies. You can find the review article about water in a previous comment.
These are great! I think sugar makes children hyper by the same mechanism that homeopathic teething tablets make them fuss less. ;)
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Friend passed this along. I never knew that sugar really didn’t affect my kids as much as I thought. I guess it was just excuses. I’m still going to have them avoid soda….