Is ADHD associated with sugar intake?

Before we go any further, let’s dispel a myth. Many of the parents of my childhood and teenage ADHD patients strongly believed that sugar makes their kids hyper. One mom, speaking of her ADHD child, told me, “If my kid eats or drinks anything with sugar in it, he’ll start bouncing off the walls. Yesterday, he had a Little Debbie snack that a friend gave him. For the next three hours, I couldn’t calm him down.”

Some of my patients even think that sugar causes ADHD. In fact, in a survey conducted by the University of Florida, 59 percent of African-American parents and 30 percent of Anglo parents attributed ADHD to excessive sugar in their kid’s diets.¹ In another study, more than 80 percent of Canadian primary school teachers believed that sugar consumption contributed to increasing activity of normal children and to the behavioral problems of hyperactive children. Moreover, in the three years prior to the study, 55 percent of all teachers had counseled parents to consider reducing their child’s sugar consumption to control hyperactivity and parents frequently did so.² However, the available scientific evidence does not support the theory that sugar consumption has significant adverse effects on children’s behaviors. ³

In fact, in researching this chapter, I identified over 20 medical studies that have evaluated the effect of sugar on the behavior of children. In the majority of these studies kids were given food or drink containing either sugar or another sweetener such as saccharin or aspartame. Then the children were observed and/or tested for several hours. The studies were “blinded.” In other words, neither the kids nor the researchers knew whether sugar or another sweetener had been ingested.

Here’s an example of one of these studies: Researchers at Vanderbilt University conducted a double-blind controlled trial with two groups of children: 25 normal preschool children (3 to 5 years of age), and 23 school age children (6 to 10 years) described by their parents as sensitive to sugar.⁴ The children and their families followed a different diet for each of three consecutive three-week periods. One diet was high in sucrose with no artificial sweeteners, another was low in sucrose and contained aspartame as a sweetener, and the third was low in sucrose and contained saccharin (placebo) as a sweetener.

All the diets were essentially free of additives, artificial food coloring, and preservatives. The children’s behavior and cognitive performance were evaluated weekly. The authors concluded, “Even when intake exceeds typical dietary levels, neither dietary sucrose nor aspartame affects children’s behavior or cognitive function.” ⁵

Virtually all of the studies that I have reviewed have concluded that there is no difference in the behavior of the kids whether they are given sugar or not. In the very few studies in which an effect was noticed, it was very faint.

For example, in a study that tested kid’s attention conducted at the Long Island Jewish Medical Center, children with ADHD who had been given sugar had slightly lower scores than the kids who had consumed aspartame.⁶ 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.⁷ These studies had the exact opposite results. However, in both of these studies the impact was barely perceptible. In fact, when doctors from Vanderbilt University looked at all twenty of these studies (in what is called a meta-analysis), they concluded that there was no evidence that sugar has any effect on a child’s behavior or mental performance. ⁸

These authors concluded, “‚Ķsugar does not affect the behavior or cognitive performance of children. The strong belief of parents may be due to expectancy and common association.” But, despite the medical evidence, I find that most parents find it difficult to accept the findings that sugar does not change behavior. Why? Simply because many parent’s observations are that when they give their kids sugar-containing food or snack drinks, they see their kids “go crazy”! Why is this?

One explanation given by the experts is that the kids may be responding to some other ingredient in sweet foods or drinks. One guess is caffeine. This would be one possible culprit in soft drinks, as a can of cola can contain as much caffeine as 1/3 to 1/2 cup of coffee.

Endnotes
<sup>1. Prinz RJ, Roberts WA, Hantman E. Dietary correlates of hyperactive behavior in children. J Consult Clin Psychol 1980 Dec;48(6):760-9.
2. DiBattista D, Shepherd M. Primary school teachers’ beliefs and advice to parents concerning sugar consumption and activity in children. Psychol Rep 1993;72(1):47-55.
3. Ibid.
4. Wolraich ML, Lindgren SD, Stumbo PJ, Stegink LD, Appelbaum MI, Kiritsy MC. Effects of diets high in sucrose or aspartame on the behavior and cognitive performance of children. N Engl J Med. 1994 Jun 30;330(26):1902-3.
5. Ibid.
6. Wender EH, Solanto MV. Effects of sugar on aggressive and inattentive behavior in children with attention deficit disorder with hyperactivity and normal children. Pediatrics 1991 Nov;88(5):960-6.
7. Rosen LA, Booth SR, Bender ME, McGrath ML, Sorrell S, Drabman RS. Effects of sugar (sucrose) on children’s behavior. J Consult Clin Psychol 1988 Aug;56(4):583-9.
8. Wolraich ML, Wilson DB, White JW. The effect of sugar on behavior or cognition in children. A meta-analysis. JAMA 1995 Nov 22-29;274(20):1617-21.</sup>