Is sugar a drug?
Sugar could have effects similar to those of drugs in people who consume a lot and obese people.But the researchers are divided.
Because food can activate the center of pleasure, as does alcohol or cocaine, the idea that sugar could be a drug has made its way. A study in 2008, which became famous, even showed that rats preferred cocaine-sweetened water. However, according to two recent meta-analyzes (1, 2) the sugar would not be strictly comparable to a drug because its “addictive” potential is due to its good taste and not to its neurochemical effects as such (inducing a lack). According to these researchers, like all other appetite foods, foods high in sugar stimulate the release of dopamine in the brain, the addictive effect would not be specific to sugar.
Nevertheless, this point of view is not shared by all researchers, like Serge Ahmed (CNRS, Paris) for whom fructose can have effects similar to those of drugs (3). Not to mention the fact that “hard” drugs do not systematically provoke symptoms of withdrawal and withdrawal, the psychological environment also having a very important role in the appearance of addictions (4).
A study published in the journal Diabetes confirms that the debate over the addictive potential of sugar is not over. According to his results, glucose and fructose, but especially the latter, in obese people would have effects similar to those of drugs (5). As a reminder, sucrose, table sugar, consists of a molecule of fructose and glucose. Fructose is found naturally in fruit (hence its name) while free glucose is rare in nature, but it is present in processed products, often in the form of glucose-fructose syrup, also called isoglucose.
The researchers observed by MRI the effects on the brain of 14 thin adolescents and 24 obese adolescents from ingestion of glucose or fructose (during and after).In all adolescents, fructose (a constituent of sugar) stimulated the activation of the ventral striatum, also called the center of motivation. This effect was not observed with glucose.
In thin adolescents, glucose and fructose activated the pre-frontal cortex, which is involved in self-control but does not affect the part of the brain that controls appetite, located in the hypothalamus. At the same time, the rate of ghrelin (the hormone of hunger) decreased rapidly. In obese adolescents, on the other hand, glucose and fructose inhibited the prefrontal cortex, and increased the activity of centers of pleasure or reward. In addition, the rate of ghrelin decreased more slowly, which was associated with activation of the thalamus, hypothalamus, and hippocampus.
These results suggest that obese adolescents have abnormal metabolic and cerebral reactions after ingestion of glucose and fructose. According to the authors, these abnormal reactions are due to their chronic over-consumption of glucose and fructose. But is this sensitivity to sugar due to obesity as such or overconsumption of sugar?
Looking at the studies, many studies report that overconsumption of sugar is one of the major causes of the increase in obesity worldwide, including a recent study in 170 countries (6). A study published in 2016 (7) reports that regular and abundant consumption of sugar, would gradually cause a decrease in dopamine receptors in a similar way to drug exposure. This would then cause withdrawal symptoms or depression.
However, if it turns out that sugar really has an addictive potential, this is also the case for junk food and foods that are very rich in taste (rich in Maillard compounds, in fat, in salt, in glutamate, etc.) and light drinks.
WHO advises not to consume more than 25 g of free sugars per day. This is the equivalent of the amount of sugar in a 220 mL coca glass (25 g). In comparison, we consume nearly 94 g of total sugars per day on average. The overconsumption of sugar would have adverse effects on memory, morale, the risk of diabetes (fatty liver), and indirectly, via overweight, on certain cancers. The overconsumption of sugar therefore appears harmful. It is possible, even if it must be confirmed, that this overconsumption creates a form of sugar dependence, which would create a vicious circle leading to obesity. This point of view, which is based mainly on studies in animals, is defended by American researchers in a recent article that looks at the effects of sugar on cocaine, but it is disputed by British researchers, for whom addictive nature of the cure is not established. ” Based on its metabolic and hedonic properties, I think sugar is addictive, ” says Dr. Robert Lustig, a researcher at the University of California, San Francisco, and author of ” Sugar, The Bitter Truth “. But he adds that his addictive potential is ” low “, similar to that of nicotine, so very different from that of hard drugs. The debate is far from over.
(1) Westwater ML, Fletcher PC, Ziauddeen H. “Sugar addiction: the state of the science.” Eur J Nutr. 2016 Jul 2.
(2) Benton D. “The plausibility of sugar addiction and its role in obesity and eating disorders.”Clin Nutr. 2010 Jun;29(3):288-303. doi: 10.1016/j.clnu.2009.12.001. Epub 2009 Dec 28.
(3) Ahmed SH, Guillem K, Vandaele Y. “Sugar addiction: pushing the drug-sugar analogy to the limit.”Curr Opin Clin Nutr Metab Care. 2013 Jul;16(4):434-9. doi: 10.1097/MCO.0b013e328361c8b8.
(5) Jastreboff AM, Sinha R, Arora J, et al. “Altered brain response to drinking glucose and fructose in obese adolescents. “Diabetes 2016;65:1929–1939.