Is there really such a thing as a sugar rush?

Everyone has heard about the sugar rush thought to accompany eating sweets, particularly parents of small children concerned about difficult behavior resulting from too much sugar. However, according to scientific studies, there is actually no such thing.

Where does the idea of a sugar rush come from? It may be suspected when people consume a ton of sugar, such as at a special event or a holiday, paired with the increased knowledge about the negative effects sugar has on health and weight.

However, a new analysis of 31 different studies has found that rather than increase alertness and provide a temporary increase in mood (which could be called a sugar rush), researchers concluded that sugar has no positive effect on mood, even if large amounts of sugar are consumed. In fact, the analysis shows that the reverse is actually true, as sugar consumption results in decreased alertness and fatigue (via BBC Science Focus).

Sugar makes up 13.5 percent of the daily caloric intake for kids ages 4 to 10, and 14.1 percent of the daily caloric intake for teenagers, according to researchers. That is almost three times the daily recommended amount. In adults, sugar accounts for 11.2 percent of their daily caloric intake. The researchers found the main sources of sugar consumption across all ages to be soft drinks, sugared cereal, sweets, and chocolate.

Early studies on the sugar rush

The new study results are actually not new at all. In 1995, researchers analyzed 16 study results of children and found that sugar did not affect their behavior or cognitive function. Prior to that, the National Institutes of Health concluded that sugar rushes don't exist — all the way back in 1982 (via Fatherly).

This brings into question all the supposedly "settled" science so many believed about sugar and the ubiquitous sugar rush. Where did it come from if science has shown it to be wrong for so long?

A study was published in Food and Cosmetics in 1973 that noted that sugar causes children to display hyperactive behavior. The study looked at 265 children whose parents complained they had hyperactive behavior, such as running around too much and having difficultly concentrating. They found the children had abnormally low blood sugar and studies have shown that low blood sugar can result in mood swings and other emotional symptoms. Low blood sugar, interestingly, can actually be caused by eating too much sugar. Thus, the conclusion was formed that the kids' hyperactivity was the result of eating too much sugar, and was deemed to be part of the now-infamous "sugar rush."

The connection between eating sugar and behavior in children

However, that isn't the whole story. Later analysis showed that the 265 children involved in the study had blood sugar levels that were within the normal range for children. Other studies were shrugged aside for showing correlation rather than causation, meaning it can't be determined from the available information whether hyperactive children simply eat more sugar than their non-hyper peers, instead of the sugar itself causing hyperactivity.

In 1994, due to anecdotal instances of children being described as sensitive to sugar, researchers did a study that looked at 50 children described this way by their parents. The children were assigned a diet that was either high in sugar, high in aspartame, or high in saccharin. Neither the parents nor the researchers were aware whether the children were consuming the actual sugar, artificial sugar, or the noncaloric substitute. All of the parents reported seeing no meaningful behavioral changes in their children (via The New York Times).

Parenting style and the sugar rush

Another 1994 study involved 35 mothers with children they claimed were sensitive to sugar. Half of the mothers were told their children were given sugar and half were told their children had not been given any sugar. In actuality, none of the children were given any sugar, but were instead given a placebo that did not contain sugar. The mothers who expected their children to have a "sugar rush" rated their children as more hyperactive. However, the researchers also observed that these same mothers hovered over their children, what we might today call "helicopter parenting," talking to their children more and criticizing them more. Researchers concluded that it is possible that parenting style is the actual cause of the "sugar rush," where parents see the behavior they are looking for, and sometimes bring it on, simply because they are looking for it.

The lack of existence of a sugar rush does not mean sugar is not bad for you. Diets too high in sugar can cause type 2 diabetes and other health problems, as well as decreased alertness and fatigue, something many call "brain fog." Sugar is also a main contributor to weight gain and metabolic syndrome (via Johns Hopkins Medicine).

But as far as an actual, scientifically-proven sugar rush? Doesn't look like those really exist.