When processed food companies began substituting high-fructose corn syrup for cane sugar, the effect on profit was dramatic. Corn was plentiful, cheap and domestic. Cane sugar was distant both geographically and politically, with supplies limited by quotas that kept prices high.
Since then, an increasing amount of research has shown that the impact on consumer health was just as dramatic. Among those closely following the scientific literature is Canadian lawyer Stephen Gleave. A successful employment lawyer in the Toronto area, Gleave’s interest in the topic is rooted in his other avocations and passions. A part-time farmer who raises Scottish Highland cattle in rural Ancaster, Ontario, he is an advocate for organic cultivation, pollinator preservation and pure, healthy food.
Stephen Gleave has compiled an extensive list of the scientific studies that have evaluated the impact of high-fructose corn syrup on human health. He often cites a University of Utah study that highlights the dangers of mass consumption of high-fructose corn syrup. Scientists tested diets heavy with either table sugar or corn syrup on mice. The result, according to the Utah researchers: “The fructose-glucose mixture found in high-fructose corn syrup was more toxic than sucrose or table sugar, reducing both the reproduction and lifespan of female rodents.”
Senior author Dr. Wayne Potts noted that “when the diabetes-obesity-metabolic syndrome epidemics started in the mid-1970s, they corresponded with both a general increase in consumption of added sugar and the switchover from sucrose being the main added sugar in the American diet to high-fructose corn syrup making up half our sugar intake.”
In the Utah study, the test mice received a quarter of total dietary calories from processed sugars, just as an estimated 13 to 25 percent of Americans do. Sugars that occur naturally in food were not counted. “One group ate a mix of fructose-glucose monosaccharides like those in high-fructose corn syrup. The other group ate sucrose. Female mice on the fructose-glucose diet had death rates 1.87 times higher than females on the sucrose diet. They also produced 26.4 percent fewer offspring.”
According to team member Dr. James Ruff, “in the American diet, 44 percent of the added sugar is sucrose, 42 percent is high-fructose corn syrup and the remaining 14 percent includes honey, molasses, juice concentrates and agave — all of which also combine fructose and glucose (which also is known as dextrose).”
From a global perspective, the amount of high-fructose corn syrup in the American diet is extremely high; the worldwide average is approximately 8 percent.
Corn syrup hasn’t been good for the health of the North American consumer, nor for the well-being of the average laboratory mouse. Each new dietary study brings more bad news, with tales of lab mice that became fat, lethargic and dispirited as a result of dining on highly-processed foods.
In a range of recent studies, rodents have reacted poorly to high-fructose corn syrup, GMO corn, fatty foods and sugar. Depending on how closely mouse menus paralleled modern patterns of consumption, morbidity accelerated, fertility cratered and males became less interested in holding territory.
Stephen Gleave describes a seminal study in which researchers at UCLA observed a group of rats who had been “enrolled in a five-day training session” to learn a complex maze, then put on a diet of high-fructose corn syrup. These nimble merit scholars became slower, duller and less likely to put the answer in the form of a question on Jeopardy than a control group whose calorie choices had fewer points of resemblance to the modern American diet.
On sugar highs, corn syrup rats struggled to remember the maze. Synaptic activity dropped. The prospect that sugar-fortified rodents might one day master the New York Times crossword puzzle became even more remote.
The appearance of insulin resistance among the rats seemed to be one of the physiological mechanisms involved. This essential hormone not only regulates blood sugar in the body, but also helps brain cells communicate with each other and store memories effectively.
“Because insulin can penetrate the blood-brain barrier, the hormone may signal neurons to trigger reactions that disrupt learning and cause memory loss,” said lead researcher Fernando Gomez-Pinilla in a UCLA report. “Our study shows that a high-fructose diet harms the brain as well as the body. This is something new.”
But there was at least one sweet discovery in the study, Stephen Gleave points out: A group of rats whose sugar intake was supplemented by flaxseed oil and other sources of Omega-3 fatty acids remembered the maze and lapped briskly along the route.
“Our findings illustrate that what you eat affects how you think,” Dr. Gomez-Pinilla concluded. “Eating a high-fructose diet over the long term alters your brain’s ability to learn and remember information. But adding Omega-3 fatty acids to your meals can help minimize the damage.”