Almost everybody tasted it long before they could remember the feeling of satisfaction, causing delicate tingling in their whole body, starting with a tiny area behind one’s mouth.

It can raise one to the heights of happiness, even is this happiness is fleeting. Despite the transience of this pleasure, most of us wish to repeat the experience; most of the times against one’s better judgement, which insistently whispers that, should one refrain, one would be better off on the long run. Still, the temptation is often much too strong to resist it. How come we cannot help it? Are we perhaps high on sugar?

How harmful sugar is

Of course, we will have the impulse to reject the label of “addicts”, which we’d much rather use for people who give in when faced with other white colored powders, lacking the unique taste of sweets. However, we hear more frequently voices, some coming from people with professional or scientific authority, saying that sugar might be a drug. Let’s go over a few headlines from the national press or Romanian internet which speak for themselves: “Addiction – Sugar, drug for the brain”; “Sugar acts like a drug at brain level. What do nutritionists say about chocolate, bread and fruit”; “What is the most dangerous drug? A health expert gives a totally unexpected answer” (the expert is Paul van der Velpen, director of the health service in Amsterdam; the answer to the question is: “It might seem exaggerated or farfetched, still sugar is the most dangerous drug of our days and it’s easy to obtain.”); “Doctors’ warning: sugar is the most dangerous drug”; “Sugar: energy or drug? – a story produced by «Romania, I love you»”; “Sugar is a drug causing addiction, obesity and other serious illness.”

The rhetoric of concern centered on sugar is not a peculiarity which characterizes the Romanian media. We can find similar headlines in the foreign media, like “Death by sugar” (New York Post) or “Sweet and vicious. Is sugar toxic? ” (The New York Times). Sober and prestigious journals such as the British Medical Journal seem to inspire themselves from the same sources, with headlines like “Sugar is the new tobacco”, and serious researchers are rediscovering John Yudkin’s book from 1950, “Pure, white and deadly”. How does sugar kill us and what can we do to stop it?

According to statistics, in 1998 each Romanian consumed an average of 20 kilograms of sugar per year, almost half a kilo of sugar each week.

After only 10 years, the average sugar consumption revolves around 30 kilograms per year for each Romanian, against a background of an annual growth of consumption. In 2014, the yearly average of sugar consumption seems to have been at least 25 kilograms, in Romania. Of course, most statistics should be taken with a grain of salt, since they can be affected by errors, by the methodology of data collection, by the sources’ reliability, by the definition of the used variables and so forth. For instance, it’s possible that not all the sugar sold in Romania (and which is to be found in the statistics) would be destined for human consumption, which requires diminishing those annual averages. On the other hand, it’s not clear to what degree do statistics also include the sugar which is already contained by food. A statistic based on Euromonitor date (a multinational company specialized in market research) claims that the daily sugar consumption of sugar per capita, in Romania is around 31,5 grams, which equals an approximate annual consumption of 11,5 kg. The statistics above suggest that the latter is probably underestimated. A variety of internet pages in Romania declare numbers around 20-30 kilograms/year, sometimes even more, for the whole period of 1980-2015. Of course, this depends on what we measure. Just the pure sugar sold in bags or also the one in the cakes, candy of refreshment drinks? How about the one added in ketchup, jams or breakfast cereal? Then, the notion of sugar is problematic in itself. Different people understand different things when they talk about “sugar”.

What should one understand by “sugar”?

In short, when talking about sugar some people think of that white substance, frequently sold in 1 kilo bags, with the label sugar on it and which, from a chemical point of view, is called “sucrose”. Others, when speaking about sugar, think of carbohydrates with a relative simple molecule: sucrose, glucose or fructose. Therefore “corn syrup rich in fructose” (a sweetener rich in fructose by hydrolyzing cornstarch), maple syrup, agave syrup (which contains a mixture of fructose and glucose, the first in a larger quantity), honey bee (which mostly contains fructose and glucose, the first in a somewhat larger quantity, but also small quantities maltose and sucrose) can also be considered “sugar”. The degree in which some are healthier (or more dangerous) than sucrose can lead to an interesting (and controversial) discussion. This, however, exceeds the space allotted for this article, in which we will manly focus on the first meaning.

On which arguments does the theory of the sugar-drug rely?

When they launch idea of the sugar as a drug in the public space, various experts do not use it just as a figure of speech, but in the proper sense of the term. The qualification as a drug of the pleasant food ingredient is based on a series of observations following certain experiments conducted on animals, which are similar to the ones observed in the case of traditional drugs. Many research labs have conducted experiments in which one could notice that lab animals (usually mice or white rats) come to excessively eat sweet food when given to them intermittently. For instance, in such a pattern, animals do not have access to food for 12 hours. After this, a sugar formula is offered to them (with similar concentration with that of commercial refreshment drinks) and rodent food. After a few days, animals start consuming a larger quantity of sugar. After the animals have been exposed to this kind of treatment, with sugar and rodent food for 28 days, a group of researchers restricted the animals’ access to food for 36 hours. This circumstance would not be very pleasant for humans either. All this aside, researchers noticed a higher degree of anxiety in the animals who had received sugar in the previous four weeks, in comparison with the animals who had been given free access to rodent food and who were also deprived of food for 36 hours. Researchers measured the level of sugar in the blood of the animals and did not notice any difference between the two groups, confirming that the state of anxiety was not the expression of a glycemic deficit. Furthermore, the animals who were used with sugar showed a high degree of extracellular acetylcholine (one of the main chemical messengers through which neurons communicate with each other) and a low level of dopamine (often described in popular language as one of the happy hormones). Such observations are similar to the ones formulated for lab animals whose administration of opioids, such as morphine, had been cut off.

In another experiment, in which animals could choose between food which was rich in sugar, with chocolate flavor, and typical, cereal-based rodent food, the rodents preferred the first (over 90% of the total calories). Three days of access to sugar have proven enough for the rats to start excessively consuming sugar, even when these were already full (hyperphagia), consuming, however, a bit of the regular good, while waiting or anticipating for the sugar-rich food (anticipatory hypophagy). The administration of an opioidergic antagonist (nalmefene, a drug with an opposite action to opioids) reduced the excessive consuming of sugar-rich food – a finding consistent with what is already known about the involvement of opioid receptors in regulating the consumption of products for hedonistic purposes and not in order to satisfy nutritional needs. The females which received a bottle of water and one with sugar formula daily, consumed large quantities of sugar, estimated at approximately 65 grams per kilo. When the two bottles were removed briefly to be refilled, as soon as they were put back the females licked the sugar bottle for a few minutes, although the bottle had been missing just for a short period of time. When, in the second week, the sugar was removed, an obvious aggressiveness was noticed, manifested by gentle biting (gripping with the mouth, without pressure) of the pen or the researcher’s hand.

In other experiments, administering glucose in large quantities (in just 10 days from receiving a concentrated glucose formula, rats ended up consuming a double quantity of glucose as compared to the first day), was associated with sensitization of the dopamine and mu receptors1 for opioids, a phenomenon similar to the one observed when administering abuse drugs. The observation is consistent with a previous experiment where, in the case of rats fed for a longer period with bakery products, the naloxone administration led to symptoms typical for the abstinence syndrome2 observed when the administration of opioids was stopped (therefore, the same type of symptoms, as if the animals were drugged). Naloxone is an antagonist of opioid receptors, used in diagnosing acute overdoses of opioids, because it antagonizes the opioids’ action and leads to quick elimination of respiratory depression and altered consciousness state. For people who have the same symptoms generated by other causes this has no effect.

It is also known that opioids alter the preference for tasty foods. People who are addicted to opioids have an accentuated preference for sweets and carbohydrate-rich foods (a preference which is diminished by antagonists such as naloxone). Butorphanol, a drug with effects similar to morphine, has induced hyperphagia manifestations in animals who had been deprived of food in the past. This was, however, not the case for animals who hadn’t been food deprived.

Unanimity? Not really.

In the context in which media and specialized journals have made a trend out of referring to sugar as a drug, with arguments like the ones presented above, there are still unconverted scientists, which remain skeptical to such labelling of sugar. These admit that sugar (sucrose) can trigger addictive behaviours, but believe these must be understood as part of the context. For instance, animal studies have shown that addictive reactions are manifestations to the sweet taste and not the caloric content (these manifestations being similar for administering saccharine, which is sweet but has no caloric intake). Also, the preference for sugar is manifested in rats and in studies designed for interventions at the level of animal’s body, so that, once the sugar goes into the animal’s mouth it can be eliminated out of the body, not reaching the stomach and, therefore, not penetrating the vascular bed (except for a very small amount). This suggests that we are rather dealing with the effect of the sweet taste than the “drug” effect.

Secondly, these addictive behaviors obtained with sugar are only based on a diet consisting of intermittent access to sugar. However, similar behaviors are not observed in animals which are given free access to sugar. Generally, for this kind of experiments, one selects only animals who prefer sugar formulas in the early stages. Therefore it is admitted that a combination between the sweet taste and intermittent access to sugar may trigger a state similar to drug addiction, and the respective animals have a more intense response to drugs that have never been administered to them, like amphetamine and alcohol. But just how relevant is this effect to regular sugar consumption?

To quote certain researchers, “it is important to emphasize that these behaviors similar to addiction are observed only in diets with intermittent access but not in the ones with ad libitum access” to sugar.

In this context, “intermittent access” means that animals are offered sugar for a certain period, for example, for 12 hours, and then this access is limited for another 12 hours and so on.

Moreover, other aspects contradict the existence of “drug” effects of sugar. For instance, rodents which are given access to sugar for a long period are affected by processes of depreciations hereof, like adding a substance which induces nausea. In such situations, animals refuse to go on consuming sugar. On the other hand, in the case of cocaine or heroin, animals keep consuming these drugs despite the negative consequences. As far as the limited data we have from humans, it is difficult to make a distinction between natural consumption of sweet foods and a pathological state of addiction. In the studies carried out so far, it has been proven that the consumption of energy-dense foods which are nutrient-poor – candy, fast-food – is correlated with a score used for diagnosing “food addiction” and with the body mass index. The total consumption of carbohydrates and sugar from different foods, including that from breakfast cereal and fruits, hasn’t been significantly associated with this score.

Drug or food?

The skeptical camp underline the idea that “sugar is no more obesogenic than any other tasty, energy-rich food”. A true fact, which many of the sugar’s critics take into consideration. The concerns related to sugar many organizations and organisms involved in the nutritional field have, refer not so much to the complete prohibition hereof, but rather to limiting it to levels which are compatible with a healthy life.

Besides, authors who believe in labeling sugar and highly processed foods as “addictive” admit to the fact that numerous studies which have examined sugar’s causal role in diabetes or obesity, did not establish a clear and unique causal relation and that it is rather the energy excess (that is food, irrespective of that being sweets, fats or even proteins) which leads to excessive body weight, obesity and type II diabetes: “Neither the consumption of sugar per se, nor the consumption of a sole nutrient can uniquely cause these morbid conditions. (…) Once the analysis for the total energy intake is adjusted, many published studies haven’t actually shown a relationship between sugar consumption and body weight.”

The risks of consuming too much sugar

According to a meta-analysis based on around 60 studies, when sugar is replaced with other nutrients with a similar energy content, “no adjustment in body weight occurs”. However, one should not ignore the fact that there is convincing observational proof that “refreshment drinks” (which all contain sugar), consumed on a frequent basis, are associated with a high risk (approximately 25%) of diabetes, compared to the risk people consuming such drinks just once a month or less take. On the other hand, critics of the “drug” label applied to sugar rather wish to avoid stigmatizing sugar, admitting, however, that it is “indisputable that sugars, as a dense part, caloric-wise, of our diets, contributes to obesity. It is also indisputable that reducing sugar (together with reducing other energy-dense foods) should be part of any weight loss diet. We must be very careful not to conclude that this is the only harmful nutrient”.

In other words, whether sugar is or isn’t a drug might be just a thin-slice inference. However, opinions rather seem to converge on the need to reduce sugar consumption irrespective of how we label it.

1.
„Sensitization of the receptors” is a pharmacological concept which can be understood in contrast with the tolerance one. If, in the case of tolerance one notices an increasingly lower effect with each repeated administration of the same substance dose, in the case of the sensitization of the receptors one notices an increasingly intense effect with each repeated administration of the same substance dose (by a tighter connection between the substance to the receiving protein). In case of typical drugs, certain receptors are desensitized (explaining the necessity felt by drug consumers to increase the dose or frequency of administration), but others are sensitized (the involved receptors and the sensitization or desensitization process varies from one drug to another).
2.
The abstinence syndrome (also known as withdrawal) describes a series of unpleasant symptoms which appear when the consumption of a drug is stopped. The symptoms vary depending on the drug’s nature and action mechanism.