Are Sugar Comas Real? Experts Say Yes

Fagjun | Published 2018-01-16 19:06

A “sugar coma” is no longer just a cutely exaggerated way to say that you’ve eaten too many sweets.

How does sugar impact our cognitive functions?

How does sugar impact our cognitive functions?


It’s a good thing, it turns out, that our parents limited our intake of processed sugar when we were younger. Unfortunately for those among us with a sweet tooth, a new study has found that consuming two specific kinds of sugar can impact our cognitive abilities. This suggests that the so-called sugar coma, a state in which people suffer a short-term stint of reduced higher cognitive functions, is as real as it gets.


We’ve long been told that too much sugar is bad for us for a variety of reasons. Sugar, for example, can do a number on our teeth. However, losing higher cognitive functions, if only for a short while, hasn’t really been on that list of health concerns. These new findings will likely add “sugar coma” to that list, giving parents another reason to put the candy jar on a higher shelf.

Sugar Coma in Real Life

The Stroop test

The Stroop test


Researchers at the University of Otago in New Zealand provided 49 participants with four drinks sweetened by four sugar types: sucrose, glucose, fructose, and sucralose. Sucralose, as the placebo sweetener, functioned as the control.


Glucose and fructose are monosaccharides, or single-molecule sugars commonly found in food and fruits respectively. Sucrose, meanwhile, is known as table sugar and is composed of both glucose and fructose. Sucralose is an artificial sweetener. Other studies have shown that not every type of sugar is the same, especially when it comes to how they impact our health.


20 minutes after consuming their drinks, the participants were asked to take three tests aimed to measure cognitive abilities. These three tests were a timed test, a math-based test, and the Stroop test, in which participants had to say the color of a printed word rather than the word itself. For example, the word “orange” may have been printed in green, which means that the participants have to say green instead of orange.


The study was also double-blind, which meant that neither the participants nor the researchers knew which sugar the participants would be getting. This is a significant component of the research, because it ensures the prevention of bias in formulating the results.

Reducing Sugar

Ice cream, chocolate, bread, pasta, and peanut butter, among many others, are sources of glucose and fructose.

Ice cream, chocolate, bread, pasta, and peanut butter, among many others, are sources of glucose and fructose.


According to the results, the individual participants who drank the beverages sweetened by glucose or sucrose scored significantly lower than those who consumed fructose or sucralose. “Our study suggests that the ‘sugar coma’—with regards to glucose—is indeed a real phenomenon, where levels of attention seem to decline after consumption of glucose-containing sugar,” said Mei Peng, one of the researchers.


“While the sample size is relatively small, the effect we observe is substantial,” Peng continues. “Future research should further quantify how different brain regions change after sugar consumption—by using neuroimaging techniques. This will help us better understand how attention deficits arise after glucose consumption.”


While one way to avoid sugar coma is to reduce our intake of glucose and sucrose, it’s not as simple as it sounds. Glucose is actually necessary for us as a source of energy. Perhaps it’s best to slowly reduce intake, possibly by switching sweeteners and reducing the consumption of sugary snacks.

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