by Jonathan Robison, PhD, MS
Gary Taubes was at it again recently, responding to “The Fat Trap” by Tara Parker-Pope spouting the same old rhetoric about how carbohydrates are poison and how the “obesity epidemic” is the result of too many carbs. As usual, his response was short on confirming evidence for his claims other than mentioning several clinical studies (no names or references) and the fact that severely restricting carbs has evidently helped him to lose weight.
The latest round of sugar bashing probably traces its origin back to an article by the lawyer (not nutritionist) Jon Banzhaf in the New Scientist in 2003 in which he argued that “fats and sugars can act on the brain in the same way as nicotine and heroin.” In a piece in The New York Times in 2011, Dr. Robert Lustig summed up the latest attack on the sweet tasting white powder from the health professionals perspective saying:
“Sugar is not just an empty calorie…It’s not about calories. It has nothing to do with calories. It’s a poison by itself.”
Of course the sugar as “empty calorie” concept makes no sense at all. A calorie is a measure of energy and carbohydrates are a nutrient – sugar has both. But that aside, the supposed dangers of sugar have certainly become legendary. Its damaging effects have been compared to those of another white powder and an entire industry – non-sugar sweeteners – has grown up around the fear produced by the legend. Experts have claimed that “most Americans are addicted to sugar” and a quick Google of sugar addiction will bring up almost 11 and a half million hits, more than 5 times the number for cocaine addiction!
What is it about this wonderful tasting stuff that inspires such trepidation? Well, the argument by the naysayers goes something like this. When people ingest sugar, it lights up the same nerve pathways in the brain that get lit up when people take cocaine. Therefore sugar must be addictive just like cocaine. In fact, the effect of virtually all drugs of abuse is largely dependent on activation of the body’s reward circuit or pleasure center – the mesolimbic dopamine system. While there are undoubtedly other mechanisms involved as well, all of these drugs exert their influence primarily by increasing the release of dopamine, which makes us feel good. So, what about sugar? Actually, it is true that eating sugar and sugary foods also increases the release of dopamine through these pathways and makes us feel good. Does this mean we are addicted to sugar? The biggest clue to the answer for this question is that sugar is only one of many factors besides addictive drugs that lights up these pathways. Here are a few others:
Winning a prize
Expecting to win a prize
A mother recognizing her child
Oh yes, and being in love!
Are we to claim a pathological undercurrent for the enjoyment of all of these? Writing in 2010 in a review article in The Journal of Clinical Nutrition, Dr. David Benton, professor of psychology at the University of Swansea, Wales summed up the reality this way:
“That such a wide range of pleasant phenomena activate these mechanisms suggests that rather than seeing the stimulation of these pathways as something unusual or worrying, it can be viewed as one of a wide range of positive experiences that routinely stimulate a common circuitry.”
Interestingly, a closer look at the details unearths other discrepancies in the comparison between sugar and drugs of abuse when it comes to mechanisms of action. In fact, although these substances all do share some common pathways, sugar actually influences different populations of nerves in the brain, causes different patterns of firing, and induces different timings of the release of dopamine. As Benton explains:
“reward response is highly dependent on the substances tested, demonstrating that multiple reward mechanisms operate that can encode for different stimuli.”
In spite of the evidence, the sugar as evil mantra is not likely to disappear anytime soon. You only have to go to the bookstore to see that – Beat Sugar Addiction Now, Break Out of The Sugar Prison, Lick The Sugar Habit, The Sugar Addict’s Total Recovery Program, How To Break Your Sugar Addiction Today, Little Sugar Addicts, Suicide By Sugar and of course Freedom from Obesity and Sugar Addiction – to name only a few titles. Even more unfortunately, many so-called experts are stuck in the food as addiction paradigm, leading to outrageous recommendations to an already confused and anxious population. In his recent book, The End of Overeating: Taking Control of the Insatiable American Appetite, physician and former Food and Drug Administration Commissioner David Kessler focuses on the alleged addictive qualities of highly palatable ( sugary and/or fatty) foods. He claims that the only way to deal with these foods is to banish them. He suggests that
“the enduring ability to eat differently depends on coming to view these foods as enemies, not friends.” The solution according to Kessler is to retrain the brain to think “I’ll hate myself if I eat that.”
We know only too well that far from moving us towards that End Of Overeating, this approach is one that has led and will continue to lead to exactly the opposite – more confusion, more anxiety, more shame and more overeating. My friend and colleague Dr. Karin Kratina has been treating disordered eating for many years. She shared the following with me about her experiences with the concept of food as addiction. She asks her clients “if I gave you a bag of sugar and a spoon, how much would you eat?” She says they look at her like she is crazy! I’m guessing this would be an unlikely response from someone offered the other white powder.
We in the health professions (and lawyers as well, evidently) seem to be constantly in need of pathologizing some food or another. I plan to write more on this soon,