Sugar Is Not Toxic
Defending sugar is not something David Katz thought he would ever find himself doing. In his two-decade-long career in public health as an associate professor at Yale University and as the director of the Yale Prevention Research Center, Katz has frequently warned about the dangers of excess sugar consumption. But now, he finds himself having to repeatedly debunk the extremist "sugar is toxic" message that has crowded out the less inflammatory evidence-based message of "just eat less sugar."
Writing last year in the Huffington Post, Katz was very clear.
"Sugar, in general, is not poison," he said. "Breast milk contains sugar. The human bloodstream contains sugar, at all times, and the moment it doesn't, we die."
To label sugar "toxic" is misleading. It implies that the sweet substance is dangerous at any dose. But of course, it's the dose that makes the poison. A single can of Pepsi, a veritable bastion of sugar, is a delicious complement to a slice of pizza. To die from an acute toxic overdose of sugar, the average adult male would have to drink roughly 58 of those cans in rapid succession. That doesn't leave much room for the slice of pizza.
Polonium, on the other hand, now that's a poison. As little as 800 nanograms -- an amount so small you could barely make it out on the palm of your hand -- is enough to kill the average adult male.
I make this comparison not to trivialize the health drawbacks of sugar, only to demonstrate that sugar is obviously not a poison.
The American Heart Association and the World Health Organization recommend that women consume no more than 24 grams of "added sugar" (basically, sugar not found in fruits or non-sweetened milk) each day. For men, that number is 37 grams. Currently, conservative estimates indicate that Americans consume roughly twice the recommended amounts. Much of that sugar comes from nutrient-deficient soft drinks, luxurious desserts, processed food, or candy. Eating too much of any of that stuff increases the risk of fatty liver disease, heart disease, diabetes, and being overweight.
Here's what we know: Eating sugar in excess, as many Americans currently do, is unhealthy. But to take that statement any further down the provocative road is simply not in accordance with the facts. For example, the American Diabetes Association lists the statement, "Eating too much sugar causes diabetes" as one of the biggest diabetes myths.
"The answer is not so simple," they qualify. "Type 1 diabetes is caused by genetics and unknown factors that trigger the onset of the disease; type 2 diabetes is caused by genetics and lifestyle factors."
But what about the scary studies out there showing that high-fructose corn syrup -- predominantly composed of two types of sugar, fructose and glucose -- engenders deleterious effects in rodents? Well, as Katz explains, the scientists orchestrating those experiments fed the animal subjects an amount of sugar equivalent to far, far more than the average human consumes.
"The levels of fructose intake invoked to produce end-organ damage in provocative articles do not occur under real-world conditions. Pushed to comparable extremes of dosing, articles about oxygen would reach far grimmer conclusions, concluding the compound is not just toxic, but uniformly lethal over a span of mere days."
Moreover, as Scientific American's Ferris Jabr points out, rodents are not humans.
"Studies that have traced fructose’s fantastic voyage through the human body suggest that the liver converts as much as 50 percent of fructose into glucose, around 30 percent of fructose into lactate and less than one percent into fats. In contrast, mice and rats turn more than 50 percent of fructose into fats, so experiments with these animals would exaggerate the significance of fructose’s proposed detriments for humans, especially clogged arteries, fatty livers and insulin resistance."
For a quick source of bodily fuel, nothing tops sugar. That's the primary reason sugary sports drinks like Gatorade have been consistently shown to enhance athletic performance. And the intermittent ice cream cone, perhaps with a friend, family member, or significant other, is not just acceptable, but healthy.
In short, sugar is a substance meant to be used strategically and enjoyed occasionally, not avoided at all costs. Don't worry, parents, a little sugar binge tomorrow is not as scarily detrimental to your kids' health as many articles on the Internet would have you believe.