Food for Thought: Is Sugar Addictive?

We all eat to survive. We need calories, and nutrition, and for our cells to bed fed in order to function. Beyond that, though, lies a realm of questions. As humans, we have an interesting relationship with food. We crave certain foods, and are sometimes told that we’re craving just what we actually need- that if our body is craving orange juice, it may be because it’s lacking in vitamin C. However, quite often, we crave foods with little nutritional value (1). What is our body telling us then? Can we distinguish between something we greatly enjoy the taste of, versus something the cells in our body need in order to grow and replicate? With these cravings, has food- sugar in particular, become an addiction to us, like drugs? Researchers are finding foods with sucrose- the white, crystalline sugar, may have an addictive quality, perhaps explaining why we so often crave the foods containing this that we know aren’t very nutritionally beneficial to us.

Ann Kelly, a neuroscientist from the University of Wisconsin, has been studying addiction and food, and why sweet-tasting and high-fat foods are so pleasurable to us. She hesitates to say that there is such a thing as “food addiction”, but says that, “in a way, food is like a drug” (1). In the lab, researchers have found that when a rat addicted to morphine becomes aware that he is about to get his fix, the brain lights up. It turns out that when a rat conditioned to like sweets becomes aware that he is about to get his fix of sugary goods, the same reaction occurs. Why? Research is still being done as to discover the reasons, but right now, the thinking is that this occurs due to a release of opioids, creating a natural high that reduces the feeling of being full.

Bart G. Hoebel, a neuroscientist from Princeton, ran a similar study related to rats and a possible sugar “addiction” (2). In this study, he gradually introduced rats to a diet with increasing amounts of sugar. The more sugar in the food, the quicker the rats consumed it. He then suddenly withdrew the sugar from the diet, shortly after which the rats experienced “addiction-type” reactions such as teeth chattering, anxiety, and shaking. He also, like Kelly, thinks this is due to the brain becoming addicted to its own natural opioids. Drugs may give the opioids a bigger, stronger effect, but sugar is being found to be quite similar.

Sarah Leibowitz, a neuroscientist from Rockefeller University, ran additional studies on rats being exposed to high-fat foods (2). Her studies showed that rats fed on high-fat diets become more resistant to leptin- the hormone that stops eating. At the same time, levels of gelanin, a brain peptide that stimulates eating and slows energy expenditure, increases. She uses this connection to suggest that early exposure to fatty food could predispose children to always needing fatty products.

These three studies are quite interesting when thinking about sugar and its potentially addictive quality. In Kelly’s study, it’s interesting that she found that the rat brain lights up in the same way for sugar as for morphine. Although the study didn’t mention the specific part of the brain that lit up, the fact that the brain recognizes sugar as something to get excited about, in the same excited way as for an intense painkiller fix, is pretty interesting. At the same time, it’s a little scary. We know that morphine addiction isn’t a good thing- is quite bad, in fact. Morphine’s a drug that, when taken recreationally, over time, can greatly hurt us. Sugar has the potential to hurt us- as a nation, we’re in the midst of an obesity “epidemic”. Could the two things be related? Could a major part of this obesity be blamed on sugar’s potential addictive quality?

The problem with that is, the answer may be maybe, but that doesn’t do much good to the increasingly negative effects of a lot of sugar on the body. Maybe it makes us feel better, puts less blame on us as the consumers, but again, that doesn’t help much. What should we do? We can blame fast food places for making foods fatty and sugary, but in the end, it’s us consuming them. Is this more a matter of will power? Maybe we are becoming “addicted” to sugar, but is exercising control over it the next step to becoming healthier? Do some people lack this will power- or have opioids produced that are too strong- too addicting- to resist? I’m bound to think the answer to that would be no, although I’d be interested to see research done on it. I think that some people are probably more predisposed, genetically, to being addicted to certain things- having more addictive personalities, but that, when push comes to shove, it’s ultimately our choice with what we choose to put in our mouths.

Hoebel and Leibowitz’s studies are interesting as well, Hoebel’s showing rats having “withdrawal” symptoms to sugar, and Leibowitz’s in suggesting that consuming sugar may have an effect on being able to acknowledge hormones responsible for telling us when we’re full. The fact that rats experience this withdrawal shows a dependency on sugar after being fed it for a set amount of time. The effect of sugar perhaps developing a kind of resistance to hormones shows the powerful nature of the substance, and could potentially be why we can eat so many sweets before feeling full. Both give great credit to sugar as having large effects on the brain, creating furthering questions about what to do next.

A major problem with the three of these studies is that they’re done on rats, and not on people. While this makes sense as a first step, there’s a huge problem when trying to translate this to human behavior Food has become something of a social act- we have social cues, social reactions- we eat with other people. By ignoring this, or by not being able to create similar situations, we are removing a large part of the feeding/eating dynamic. It definitely is interesting that sugar may potentially be addictive, and the fact that rats, as far as we know, don’t have unusual social standards for eating on their own, shows this even more greatly. However, the role our social eating habits play cannot be undermined, and may even further add to sugar’s addictive qualities. Maybe, in the same way that morphine makes organisms feel good, sugar’s comforting qualities are all there is to it. I’d be interested in knowing exactly why opioids are released from sugar- the chemical properties that do it, but, that aside, it’s interesting to think of the sweets we crave as being compared to an intense narcotic, even on a basic level.

While these studies are just beginning to tap into the potentially addictive quality of sugar, they could bring about major developments in several areas. All three studies could be used in attempting to understand/explain eating disorders, which have had a mysterious quality for quite sometime. The association between food and mental pathways has always been blurry, but gaining evidence to back up claims- finding drug-like withdrawal and addictive qualities of food, could add a new dimension to this area. Research on obesity could also greatly benefit from these studies, since as soon as we can find, or better understand the effects of food on the brain, the sooner we can figure out either how to stimulate similar effects without food, or, perhaps better yet, figure out alternatives that don’t potentially have lows to fall down to or potentially deadly side effects.

Sugar does have its value- fructose sugar, found in fruit, lactose sugar, found in milk, and maltose sugar, found in grains, have nutritional benefits (3). However, in these studies, the sugar they’re talking about is sucrose, thought to suppress the immune system by causing the pancreas to secrete large quantities of insulin to break it down. While being able to give off “quick” energy (4), the problem is that most people consume far more sucrose than they can actually use as energy, storing much of the rest as fat, leading to weight gain, higher blood pressure, and many more maladies. As more research is being done, we’re left to think about the potentially powerful effects of sugar. I’d be interested to see more research done on cravings themselves- since we don’t know which cravings are our bodies lacking in nutrients versus mental desires for certain foods, it’d be useful to find some distinguishing factor, if one exists. We know that we must eat to survive, but do we survive to eat? Until more conclusive research is done, we’re left to crave, control what we can and choose to, and attempt to make the “healthiest” decisions- as we best know them, we can, until we learn more about what to do next.

Sources:

1. Is Junk Food Addictive? http://www.cbsnews.com/stories/2006/11/30/eveningnews/main2220356.shtml
2. Why do we Crave Unhealthy Food? http://www.bupa.co.uk/health_information/html/health_news/190703addic.html
3. Sugar. http://www.hps-online.com/foodprof1.htm
4. A New Way to Look at Carbohydrates.
http://www.whfoods.com/genpage.php?tname=george&dbid=115