‘Sugar Comas’ Are Real And Hamper Your Brain Function


If you have a sweet tooth like me then you are used to those warnings from your concerned mum about the dangers of sugar.

While I chew on Jelly Tot after Jelly Tot my mother always makes sure that she is present to remind me that sugar is bad for your teeth and your brain.

Of course I continually ignore everything she says and instead just move onto my packs of Smarties munching in blissful peace.

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Turns out though that mother does indeed know best as a new study has revealed that sugar does have a serious impact on the brain.

A research team of scientists in New Zealand have found evidence that suggests ‘sugar comas’ are real as glucose-containing sweeteners are indeed linked to reduced attention and response times.

The study, which was recently published in the online scientific journal Physiology and Behaviour, used placebos and double-blinds to see how 49 people reacted to glucose, sucrose (table sugar), fructose (fruit sugar) and sucralose (artificial sugar).


Consuming drinks that were sweetened with these different sugars, the participants had to then complete three simple cognitive tests that tested both their attention span and reaction times.

Blood sugar levels were also measured during testing and the results were definite.

Those that had consumed the drinks which had been sweetened with glucose or sucrose performed worse on these tests than the people that had consumed fructose or sucralose.

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Study author Mei Peng, a lecturer in sensory science at the University of Otago, spoke to the PsyPost about the importance of the research.

She said:

I am fascinated by how our senses influence our behaviour and affect our everyday lives.

In particular, how sugar consumption might change the way our brains work. In the case of sweetness perception, we have evolved to favour this taste.

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.

While the sample size is relatively small, the effect we observe is substantial.

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.

As food is becoming increasingly diverse, accessible and delicious, it is important to conduct more research in this area to understand food choices and eating behaviours.

Although there is more research to be carried out, this isn’t the first time that studies looking at the effect of glucose on brain function has led to these results.


Although previous studies have had mixed results, it seems that more and more data is being gathered as evidence that proves sugar comas are indeed a thing.

Glucose is a strange thing though as other research has linked it to improved memory performance despite its negative effect on attention span and response times.

It will be interesting to see what the team’s further studies discover.