By Kathleen Meister, M.S.
Posted: Thursday, February 7, 2002
Publication Date: February 7, 2002
"If my son eats anything with sugar in it, he starts bouncing off the walls. He had a piece of cake at his cousin's birthday party last Saturday, and I couldn't get him to settle down for the rest of the day. The next time he goes to a party—no cake!"
If you're a parent, you've probably heard a lot of comments like this one. Many people think that eating sugar makes kids "wired." Some even think that sugar can cause attention-deficit hyperactivity disorder (ADHD). In a survey conducted by University of Florida researchers, 30% of white parents and 59% of African-American parents attributed ADHD to excessive sugar in children's diets. In another study, 41% of a group of elementary school teachers said that hyperactivity could be caused by sugar or other food ingredients.
What the Research Shows
At least 23 scientific studies have evaluated the effect of sugar on children's behavior under controlled conditions. Most of these studies followed the same general design: children were given foods or drinks containing either sugar or another sweetener (aspartame or saccharin), and the researchers observed and tested the children's behavior for several hours afterward. Neither the children nor the researchers knew which sweetener each child had received until after the study was over. Some of these studies involved normal children, others involved children who were believed by their parents to be sensitive to sugar, and still others involved children who had ADHD or other psychological or physical problems.
All of the studies reached the same general conclusion: when you give kids sugar under controlled conditions, nothing much happens. Most of the studies found no noticeable effects. In a few studies, subtle effects were detected, but they weren't always in the expected direction. For example, in a study at Long Island Jewish Medical Center, children with ADHD who had consumed sugar had poorer scores than those who had consumed aspartame on a test of attention (which you might expect), but in a study at the University of Toronto, activity levels in children who had drunk sugar-sweetened Kool-Aid were slightly lower than those of children who had drunk aspartame-sweetened Kool-Aid (exactly the opposite of what you might expect). Overall, these minor effects tend to cancel each other out. When scientists from Vanderbilt University performed a combined statistical analysis of all of the studies (including these two), they found no evidence that sugar has any effect on children's behavior or cognitive performance.
But I've never met a parent who finds that conclusion easy to believe.
The problem here is that parents have seen kids go wild after eating or drinking something sweet. I've seen my own children do it. Some children seem to do it consistently, every time they eat something sugary, and some parents are so convinced of sugar's effects that they go out of their way to prevent their children from eating sweets (even to the point of just saying no to birthday cake). Yet the research results tell us that sugar is not at fault.
So if it isn't the sugar that's causing our kids to bounce off the walls, what is it?
What's Really Happening Here?
One possibility is that the kids are reacting to some other ingredient in sweet foods or drinks. Caffeine is an obvious candidate here, especially for kids who love soda. A can of cola contains about one-third as much caffeine as a cup of brewed coffee. Most children don't consume a lot of caffeine (in one study of school-age children, the average caffeine intake was only about 16 mg/day—half the amount in a can of cola), but some kids are exceptions to this rule, and some individuals are more sensitive than others to the effects of caffeine. So perhaps caffeine is the culprit in at least a few instances.
Food dyes, on the other hand, probably aren't a factor. The idea that food dyes could cause hyperactivity was proposed almost thirty years ago by Dr. Ben Feingold, and it was received quite enthusiastically at first. But scientific studies similar in design to the sugar studies described above have shown that dyes aren't as important as Dr. Feingold believed. Practically all children who seem to respond to food dyes under uncontrolled conditions don't respond when they're tested in controlled experiments. The percentage of children who may have a true behavioral response to food dyes is at most very small. If your child seems to react to sugary foods, it's very unlikely that colorings in the foods are responsible.
Parental expectations are probably more important. If we parents think that our children react to sugar, we may interpret their behavior in this way even if nothing is really happening. This was demonstrated in a somewhat devious study at the Menninger Clinic. The researchers there gave some supposedly sugar-sensitive boys Kool-Aid that was sweetened with aspartame. The mothers of half of the boys were told, falsely, that their sons had been given sugar. The other mothers were told that their children had received an inactive "placebo" drink. Then the researchers watched the mothers interact with their sons. The mothers who thought that their children had received sugar stayed closer to their children and made more efforts to control their behavior than the other mothers did (presumably because they were expecting trouble). They also rated their sons' behavior as more "hyperactive," even though the boys' actual activity levels were lower than those of the boys whose mothers had been told that they had received a placebo. Clearly, expectations affect the ways in which parents and children interact and the ways in which parents perceive their children's behavior. Expectations might even affect a child's actual behavior. If you tell a child often enough that he goes nuts after he eats candy, he may very well do just that.
A sort of "special occasion effect" may also play a role. In our culture, sweet treats are usually associated with special occasions—such as parties and holidays—and these events in themselves may be stressful or exciting for children. Small children may misbehave on special occasions because their routine has been disrupted (especially if they have missed their naps). Older children may "act up" because they are enthusiastic about the event, because the situation is less structured than usual (e.g., classroom parties), or because the adults are too busy to supervise them closely. In some families, especially those in which parents usually forbid children to eat sweets, the mere fact that a child has been allowed a rare sugary treat may be exciting enough to cause an outburst of "wild" behavior.
Of course, some people would say that it doesn't really matter whether sugar causes kids to misbehave; if this belief prompts parents to give their kids carrot sticks instead of cookies, it's a good thing, whether or not it's really true. But you'll never see ideas like that on this web site. At ACSH, we favor facts over fiction. People make better choices when they have correct information. If your child gets out of control at birthday parties or other special events where sweets are served, you need to know that preventing him from eating sweets on those occasions isn't likely to help. Other changes—such as explaining beforehand how he should behave, making sure that there's plenty of adult supervision, or removing him from the situation as soon as trouble starts—are more likely to be effective. But if you're focusing your attention on the menu, you may not think of these things.
Besides, a birthday party wouldn't be a birthday party without the cake.
Kathleen Meister, M.S. is a freelance medical writer and former ACSH staff member.
Responses:
March 10, 2003
Presumably, Kathleen Meister is basing her information about food dye not affecting behavior on the Kavale and Forness meta-analysis of 1983. This is the most-often-quoted source of this statement. However, this is an analysis of studies that the NIH in 1982 had already said "do not appear to have addressed adequately the role of diet in hyperactivity." Furthermore, this analysis is twenty years old.
Thoughts:
—Analyzing inadequate studies does not make them adequate.
—Incorporating an old analysis of inadequate studies into newer reviews does not make them new.
—Testing children with 5 mg or even 50 mg of one food dye does not prove anything about the Feingold diet.
—Finding that only a few children tested with 5 mg or 20 mg of food dye react to it does not mean that the 150 mg in 1 Tb of green ketchup are harmless. Nobody has done research on the levels currently used.
—On how much research does Meister base her assumption of parent expectations? Is this her own opinion? If parent expectations can make children hyper, why aren't we treating or changing parent expectations instead of claiming that ADHD is a biological brain-based illness and medicating the kids? Should we be medicating the parents?
If you are working for a drug company-affiliated or food industry-affiliated organization, your bosses will not want to know about the information I'm sending. But I would like to appeal to your conscience in the name of the more-than-7-million children with ADHD.
Oh, yes — one more piece of information you will like. There is a brand-new bit of information on how to make rats hyperactive: by giving them sugar after amphetamine. Hmmm. I wonder how Ritalin fits into this picture?
—sheilaberman
October 7, 2003
It is not necessarily the immediate response, but the breakdown four to five hours later that becomes the real problem. Emotional instability, grouchiness, and just plain bad behavior have become so predictable in my child after she has had a sugar hit. I also know this from my own experience, because I am sensitive to sugar as well. I may feel OK after eating sugar, but I have noticed a pattern of being short-tempered and just plain ornery hours after I have had sugar.
—metrographix
April 26, 2004
Children being diagnosed as A.D.(H.)D. fall into many categories. Not all are sugar-sensitive. Not all are allergic to food dyes. Not all have auditory perception problems, and some have eye problems that the modern study of optometrics can cure. Not all have parents with lax parenting skills, and some need a creative or multi-tasking method of learning. Not all have sleep apnea, and some have medical problems that require immediate attention. All of them usually have either one or more of the above, and for each child the cures vary.
The problem with these sugar studies is the assumption that all children will respond to sugar in the same way. Based on the work and research that we have been doing, if children are sensitive to "sugar," simply reducing or adding sugar to their diet will neither help them nor prove anything. These children need a specialized diet, based on the type-2 diabetes type, where sugar cravings are replaced by protein with a complex carbohydrate, and the child must eat a small amount every ninety minutes to two hours, in order to keep his blood-sugar levels stable. If the child is sensitive to wheat, the carbohydrate cannot be a whole wheat cracker. The diet will not instantly cure him.
Studies, or professionals, refuting parents' observations are quite intriguing, since the main source for the diagnoses of A.D.(H.)D. is firsthand observations of parents and teachers. Psychologists and many doctors approach issues with the knowledge that they have, without being aware that there are many, many children being _helped_ and whose lives have been completely turned around with appropriate attention and care. Approaching a child's personal circumstances, with the understanding that diagnoses have been developed in order to be able to cure the patient, makes the A.D.(H.)D. diagnosis an opportunity to find the possible source of a child's behavior and/or learning problems. Not all children will need the same therapy or cure, and professionals need to become more aware of the many possibilities that are available today to help these children. They can then go on to publish their own findings, as they will have had great success, instead of reading other people's findings, and then refuting first-hand parental observations. (By the way, it is known that part of the twenty-three sugar studies were funded by the sugar industry.)
Sincerely yours,
Mrs. Eydl Reznik
Coordinator
The Right Track/B'derech Hamelech
