Last week I wrote a bit about cotton, probably the most important commodity in the making of the modern world. But sugar comes in a close second. Sugar was the centerpiece of the Atlantic slave trade at least a century before cotton was. And now that so much of our clothing is made out of synthetic, petroleum-derived materials (there’s another commodity to learn about), sugar is once again more important. One angle for thinking about sugar is its role in nutrition and public health. I’ll share a few things I’ve learned in that regard, but I’ll also go a few centuries back into the history and political economy of the powder. It seems to me that the public health crisis around sugar becomes even more profound when you consider its origins, in some scholars’ views, as the drug that made the industrial revolution possible.
Domino Sugar Factory, Brooklyn (built 1882). © 2011 Alanna Rios
The nutrition journalist Gary Taubes was on EconTalk discussing his new book, The Case Against Sugar. Taubes is known for polemical, opinionated views about food science and this book is no exception. It is framed as a “prosecutor’s brief” alleging that sugar is the primary cause of obesity, heart disease, and all other ills of the Western diet. This one-sided argumentative commitment struck some academics as unscientific from the get-go, but I’m sympathetic to what Taubes is trying to do. He recognizes that, because there are no long-term randomized control trials, it’s impossible to make the airtight version of his argument. But he wants to draw our attention to neglected evidence that sugar should be the leading suspect. This claim is in opposition with the more cautious consensus that obesity has many dietary and non-dietary causes, among which sugar can get in line with fat, processed foods, cholesterol, and lack of exercise. Taubes thinks it’s essential that we narrow down the one true cause. The stakes are high: the CDC says more than one third of U.S. adults have obesity and that the annual costs of obesity-related medical care exceed $200 billion. The director of the World Health Organization recently called obesity and diabetes among the “biggest global health crises of the 21st century” and “a slow-motion disaster.”
Taubes presents evidence that excess sugar is the fundamental cause of a condition called insulin resistance, which itself is the cause of type 2 diabetes, which is highly correlated with obesity. So if you follow that causal chain through insulin resistance, you can get from sugar to obesity in just a few reasonable leaps. The details of that insulin resistance story make up the chemical half of Taubes’s argument against sugar. The other half is a historical examination of how sugar consumption constituted the biggest change in the Western diet in the past 200 years. Per-capita sugar consumption increased 30-fold in that period, peaking in 1999 when Americans were getting 20% of their calories from sugar.
In addition to making the case against sugar, Taubes attacks other nutrition researchers for missing the story. One target is the theory that obesity is simply a matter of over-eating and under-exercising: a “caloric imbalance.” In this view, sugar is not good in that it entails “empty calories,” but is no worse than any other such source. A complementary theory that many of you may have internalized is that dietary fat is the main cause of obesity. Taubes shows a history of shady research funded by the sugar lobby making the case against fat. On the other hand, as this review of the bookpoints out, the opposite is also true as meat and egg industry groups have sponsored plenty of negative research on sugar. It’s probably best to ignore all such industry propaganda.
One aspect of Taubes’s dismissal of other theories of obesity that I found curious was his repeated invocation of Occam’s Razor to justify his insistence that we must find the single prime mover of obesity. He is frustrated with those who say obesity is a “complex physiological response” and therefore no single cause can be identified. Lung cancer is also a complex response, but smoking has been identified as the main cause (associated with over 80% of cases, per CDC). I agree with this point that the complexity of the human body is no guarantee against monocausal explanations, but I’m not sure it follows that there must be a single cause. Occam’s Razor provides no insight on what level of abstraction should be used for judging the relative simplicity of arguments. Taubes seems to be working at the level of macronutrients, so a theory that involves just one macronutrient (carbohydrates) is “simpler” than one that involves two or three. But at a higher level of abstraction, you could treat “Western diet” as a single cause and still have a maximally simple theory without distinguishing between sugar and fat. So I really don’t think Occam’s Razor gets him very far here.
Unsurprisingly, Taubes has earned plenty of pushback for his arguments. Here is one forceful rebuttal from a nutrition researcher (although, the kind of person who appends “PhD” to their title…). One interesting argument in that piece is a response to Taubes’s claim that while other civilizations have consumed processed grains, no civilization ate very much sugar prior to the modern West. Guyenet points out that some hunter-gatherer groups have subsisted on a seasonal majority-honey diet without evidence of insulin resistance or obesity, which he takes as evidence that the total calorie load is the important thing. On the other hand, some honeys consist of more glucose than fructose, which is the really bad sugar. In this Cato forum, Taubes fights back against this critic and others. One point several critics had made is that U.S. sugar consumption has declined slightly since 2000 while obesity and diabetes have continued to increase. Damning evidence? Taubes shows that lung cancer didn’t begin to decline until 30 years after smoking did. “It would indeed be nice if our bodies, both on a population-wide and individual basis, responded immediately to the removal of a toxic substance from the environment. But there are many reasons why they wouldn’t, among them being threshold effects, intergenerational effects… and an incubation period for development of the disease.” The threshold effect seems like the most important one: sugar consumption is still an order of magnitude greater now than during the industrial revolution.
So let’s go back to when sugar was a luxury for special occasions. The story of how sugar became so important to the Western diet is told in Sidney Mintz’s book Sweetness and Power. The first hints of sugar’s unique role came as early as the 12th century, when Thomas Aquinas settled an important theological question by judging sugar to be a medicine, not a food, and thus exempt from the fast. The idea that sugar doubles as a drug–good for easing digestion, or for stimulating a worker’s energy–recurs throughout Mintz’s narrative. In Aquinas’s day, sugar was an utter luxury cultivated in the Middle East. By the 1400s, it was a key vehicle for conspicuous consumption; sugar-based sculptures were popular centerpieces at banquet tables, and having a flock of birds (or other animals) burst out of a pie was the height of entertainment. But sugar didn’t become a mass commodity until it was produced cheaply, and it wasn’t produced cheaply until the British opened slave plantations in the West Indies. J.S. Mill offered a remarkably blunt analysis of what the island colonies were: “These are hardly to be looked upon as countries…but more properly as outlying agricultural or manufacturing estates” belonging to the mainland.
Like Empire of Cotton, which I discussed last week, Mintz is telling the story of how the Industrial Revolution was built on the back of slave labor. Unlike Empire of Cotton, he is also showing how the invention of an industrial working class required the simultaneous invention of mass consumption. To see this, consider an important shift in how the British state thought about its sugar industry. In the 18th century, the sugar trade was thought to mainly benefit the sugar planters. Most of them lived in England, sat in the House of Commons, and pushed a protectionist agenda to exclude non-British sugar. But as sugar grew cheaper and more integral to the working class diet, state policy shifted from this production logic to a consumption logic. With the 1846 Sugar Act, Britain opened up sugar imports to Brazilian, Cuban, and other producers: “By removing barriers to “free trade”…the leading sectors of British capitalism sold out their planter-capitalist fellows.”
So the next question is: why was sugar so important to the working class? I can’t delay Mintz’s explosive punchline: “The hypothesis offered here is that sugar and other drug foods, by provisioning, sating–and, indeed, drugging–farm and factory workers, sharply reduced the overall cost of creating and reproducing the metropolitan proletariat.” That claim is so provocative it deserves a much longer book in its own right, but Mintz sketches what he means. He argues that sugar consumption must be understood in the context of an inadequate diet, lack of hot food especially for midday meals, and new schedules of work and rest as the society adapted to a more urban, time-conscious character. Sugar entered Britain around the same time as three other stimulants grown in colonies: coffee, tea, and chocolate. All three are bitter on their own and seem to improve with sugar. Tea, especially, emerged as an essential tool for making a cold meal seem like a hot one (it was common to dip bread in tea to make it more lively). The time-crunched nature of the urban workday plays an important role in Mintz’s argument. He presents evidence that when mothers started working in textile factories, children’s meals grew less nutritious and more dependent on molasses and jam for quick calories. This analysis reminds me of the argument thatChris Arnade makes in defense of McDonald’s: that it’s an extremely sensible choice for people short on both money and time (conventional discussion of poor people’s food choices seems to underplay the time element).
By framing sugar as a palliative used for easing the transition to industrial capitalism, Mintz places it alongside other coping drugs like tobacco, alcohol, and, yes, opioids. In this light, perhaps a Bloomberg-style war on sugar looks like normal drug policy. In truth, I don’t know much about the public health strategies people are proposing to deal with our likely dangerous level of sugar consumption. I’d like to learn more. In doing so, it seems important to remember that the class disparity in sugar consumption is baked into the food’s earliest appearances in the Western diet as the very first mass commodity.