• Sugar, and candy, do not make kids hyper – ctd.

    I sent the following to Andrew Sullivan, but I thought it would be useful to post here as well:

    I read with interest some of your readers’ responses to your post on my post. I’ve been getting similar comments all The Incidental Economist as well. Here’s the thing. Anecdotes are not the same as studies. Not even a collection of them.

    I will concede that you can’t prove a negative. Therefore, I cannot prove that there isn’t a single child out there who is sensitive to sugar. The question is, rather, whether this is a widespread phenomenon or whether parents can identify if they have such as a child.

    As to the former, it doesn’t appear to be so. As I said in my post, there have been many randomized controlled trials on this topic. RCTs are the most powerful types of studies, and the only ones that can prove causation. They don’t find a relationship. Yes, one individual author may hedge and say it’s not enough, but the whole sum of them are rather convincing.

    Let me give you an example of how they work. We divide kids into two groups. One gets sugar, the other gets a sugar-free substitute. Then we measure hyperactivity. There will be kids in both groups who are hyper and kids who are not. The important question is whether there are more kids in the sugar group than the non-sugar who are hyper.

    There aren’t. This means that the hyperactivity, while present in some kids after sugar, isn’t caused by the sugar. Some parents who see hyperactivity in the sugar group will believe so, but there will be just as many in the non-sugar group.

    As to the second idea, whether parents can accurately identify those kids who are sensitive to sugar, I point you to the study I summarized:

    [C]hildren were divided into two groups.  All of them were given a sugar-free beverage to drink. But half the parents were told that their child had just had a drink with sugar.  Then, all of the parents were told to grade their children’s behavior.  Not surprisingly, the parents of children who thought their children had drunk a ton of sugar rated their children as significantly more hyperactive. This myth is entirely in parents’ heads. We see it because we believe it.

    Parents who believe their children are hyper when they get sugar are conditioned to see it, even when their kids aren’t given real sugar. They’re not reliable.

    As to the red dyes, the evidence there is not compelling either (emphasis mine):

    Adverse behavioral responses to ingestion of any kind of candy have been reported repeatedly in the lay press. Parents and teachers alike attribute excessive motor activity and other disruptive behaviors to candy consumption. However, anecdotal observations of this kind need to be tested scientifically before conclusions can be drawn, and criteria for interpreting diet behavior studies must be rigorous. Ingredients in nonchocolate candy (sugar, artificial food colors), components in chocolate candy (sugar, artificial food colors in coatings, caffeine), and chocolate itself have been investigated for any adverse effects on behavior. Feingold theorized that food additives (artificial colors and flavors) and natural salicylates caused hyperactivity in children and elimination of these components would result in dramatic improvement in behavior. Numerous double-blind studies of the Feingold hypothesis have led to the rejection of the idea that this elimination diet has any benefit beyond the normal placebo effect. Although sugar is widely believed by the public to cause hyperactive behavior, this has not been scientifically substantiated. Twelve double-blind, placebo-controlled studies of sugar challenges failed to provide any evidence that sugar ingestion leads to untoward behavior in children with Attention-Deficit Hyperactivity Disorder or in normal children. Likewise, none of the studies testing candy or chocolate found any negative effect of these foods on behavior. For children with behavioral problems, diet-oriented treatment does not appear to be appropriate. Rather, clinicians treating these children recommend a multidisciplinary approach. The goal of diet treatment is to ensure a balanced diet with adequate energy and nutrients for optimal growth.

    Not that I expect this will settle the debate. I’m becoming convinced I will never win this one.

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    • Thanks Aaron. Why not give yourself a break and write a few posts on how vaccines don’t cause autism and video games don’t cause violent behavior? Sounds like a good way to start the weekend.

      • Actually, I start vacation tomorrow. Otherwise, I would. 🙂

      • Actually, there has never been a proven link between videogames and violence. Anywhere. Not one. On the other hand, there have been several studies of children who play games that indicate a decrease in aggression–many kids, apparently, use these games to “burn off” stress and aggression. Also, these kids clearly understand the difference between videogame violence and real-world violence. You might find it interesting to note that juvenile violent crime in the US is at a 30-year low–and this at the same time that videogame play has been on the increase for decades. Go figure.

        If you’re interested in getting some facts about games, start here:
        http://www.pbs.org/kcts/videogamerevolution/impact/myths.html

    • All of this has to do with short-term, acute hyperactivity? Have there been any studies looking into the effect of chronic sugar ingestion on behavior? I would hypothesize that the % calories from sugar in the first say 8 years of life would be related to ADHD and other behavioral disorders. I would go further and say there would be a negative relationship between the % calories from fat and behavioral disorders up to a point.

    • I apologize for the sarcastic (and actually rude) tone of my comment on your post preceding this – I was lazy and cut and past my comment FB wall sharing of this article. (I should have taken the time to edit out this sarcasm and approach the subject more seriously). My sarcasm stems from annoyance which in turns stems from the mere title of this article which really deserves the word “might” in it. The answer to the question of what causes hyperactivity or ADHD is still “we don’t know”. Why did you choose to ignore other studies (and more recent studies) that show on the contrary possible links between sugar and hyperactivity? I’m guessing you’ve also encountered this controlled study as well for example: http://www.nejm.org/doi/full/10.1056/NEJM199011153232001#t=article

      Actual brain scans (which is obviously a trickier study to do in pediatrics) showing possible links between abnormalities in brain glucose metabolism. I’m still on the “we don’t know” side (or middle, rather) of the debate nonetheless.

      Intuition and my own observations tell me sugar is NOT what makes a kid bounce off the walls or general “hyperactivity” in the non-clinical, colloquial sense. My toddler daughter bounces off the walls all the time with or without it, and it’s so much joy to have a kid with so much energy and life. I’m worried though some readers might take this further to mean “sugar absolutely has no effect on behavior/mood”. I think it is field that still deserves much research and trials and not to be scoffed at or labeled a myth; the possibility of a healthy diet to treat ADHD and related disorders (vs. Methylphenidate) could do such good for families.

      But beyond all the complexities of the brain metabolism (although there are a plethora of studies suggesting neuroprotective effects from lower levels of brain glucose) there are still much better understood metabolic pathways and effects of sugars and carbohydrates in general. We know that sugar triggers an advanced insulin response and is mostly likely the predominant cause of type 2 diabetes and obesity and we’re in an epidemic of such (http://www.healthpolcom.com/wp-content/uploads/2008/06/diabetes-growth-trend-1980-2005.jpg). We know that excessive amount of sugar can lead to dangerous sugar crashes or hypoglycemia in some individuals.

      To conclude with yet another dose of sarcasm (sorry) … to your offer “I thought I’d protect your children from this myth.”, thanks, but based on the other things I know about the subject, I’ll protect my child from this continuous meme that “sugar isn’t that bad.”

      • Let’s start with the fact that I ended my piece with the following:

        This does not mean that there aren’t a ton of great reasons why our kid should not ingest large quantities of sugar. As almost any parent knows, sugar has been linked to cavities and the obesity epidemic. Just don’t blame it for your child’s bad behavior.

        So I’m not advocating that sugar has no bad effects. Of course it matters for obesity and type 2 diabetes. It just doesn’t make your kids hyper.

        All of the studies that “show” a link are in some way related to in vitro protocols. Brain scans. Lab values. But for this myth’s purposes, it’s behavior that matters. People think that if I give my kid candy, the act differently. And in all the randomized controlled trials (note not observational studies), no behavior changes can be found. That’s the main outcome of interest.

        And if you can’t detect the tongue in cheek humor of the fact that I’m “protecting” kids by advocating that they can have a little extra candy on Halloween, then you need to read the blog more often.

    • Aaron,

      Can you comment on whether there are any studies that evaluate whether hyperactivity is affected by whether or not the children (not the parents) believe that they have been fed sugar?

    • Nice post Aaron, but I have one comment.

      I’ve seen this line in a few posts lately at this site:
      “RCTs are the most powerful types of studies, and the only ones that can prove causation.”

      I think you should be careful about using this line. I agree that RCTs are superior to observational studies for a number of reasons and there are numerous examples where observational findings have been disproven by RCTs (HRT for example).

      However, there are a number of areas where a RCT is either not ethical or possible. If RCTs are the only way to prove causality – do we not have proof to suggest smoking causes lung cancer or that HPV causes cervical cancer?

      I’d prefer a more nuanced consideration of causality – using something like Hill’s causal criteria which includes epidemiologic and laboratory based evidence. When you suggest the RCTs are the only way to provide causality, readers could infer that these type of molecular and observational studies are not worth consideration or funding.