In a previous blog, I referenced the only long-term study of mouse obesity, which found that it wasn’t true that a calorie of anything was equivalent to a calorie of any other food. The scientists conducting the study found that mice fed high-fructose corn syrup gained weight much faster, even on diet with the same number of calories. The authors of the paper suggested that the increasing use of the sweetener, an artificial product which is not digested in the same way as other sugars, could be a major factor in the current “epidemic” rise in obesity and adult onset diabetes.
Sorting through papers, I came across the scientific study that first led me to suspect high-fructose corn syrup is a public health threat. Hold on tight, because this is hard core science, which only unexpectedly turned out to have a bearing on human health.
Dragonflies were the objects of this Pennsylvania State University investigation. The scientists involved were studying dragonfly parasites, and how they were affecting their hosts. During that investigation, they discovered than non-mammalian species can suffer from the same kind of metabolic syndrome that has led to an epidemic of diabetes 2 in humans.
To survive, dragonflies need strong muscles for hunting and for aerial combat with rivals, and modern scientific instruments can measure the effectiveness of those muscles. Looking closer at poorly performing dragonflies, they found the parasites. These had activated a kind of molecule that leads to insulin resistance (inability to use the insulin the body produces; diabetes 1 involves a failure to produce insulin; in both cases, the lack of effective insulin causes problems in metabolizing sugars, and too much sugar in the blood leads to all sorts of bad consequences). It was the same molecule found in cases of human insulin resistance (metabolic syndrome). As with human insulin resistance, the muscles oxidized only carbohydrates, not a mixture of carbohydrates and fats. The unused fats accumulated around the dragonflies’ muscles--as they do around human skeletal muscles when there is metabolic syndrome.
The authors observed that most theories assume that too much fat in the human body promotes a chronic inflammatory response, and that leads to metabolic disorders. In dragonflies it was just the opposite: the parasite infection triggered an inflammatory response, and that affected metabolism “This finding begs the question of whether something similar might be happening in human metabolic diseases, the root causes of which remain poorly understood despite intense study,” the authors of the paper in the Proceedings of the National Academy of Sciences wrote.
Human and microbes continually coexists—the often-quoted figure is that there are about 10 trillion human cells in a body but around 100 trillion microbial cells. The study’s authors wondered if something might be happening to disturb the human intestinal environment and promote the existence of bacteria that secreted substances that promoted metabolic syndrome, along the lines of what the dragonfly parasites had done.
“One change in the human environment is the dramatic increase in soft-drink consumption among Americans, estimated to be 500 percent over 50 years from the 1940s to the 1990s,” said an account of the scientists’ work. “We looked in the literature and found that consumption of high-fructose corn syrup often is associated with gastrointestinal disease, which may be a sign that fructose affects the gut microbial flora,” wrote one of the researchers
They found further support for the idea in looking at the way some AIDS patients have chronic problems with a protozoan parasite called Cryptosporidium, which over time impaired their metabolisms in the same way the dragonfly parasites had disturbed theirs. “That information gave us the courage to connect the dots,” said Penn State researcher James Marden. “Granted, it is a big extrapolation to think that our dragonfly results might have relevance for human disease, but it would be irresponsible of us to not point out these possibilities. People who study metabolic disease should test the hypothesis that changes in gut microbial composition can cause these syndromes.”
As a society, we need the courage to connect the dots and at the grim results of the Big Corn industry stuffing us with high-fructose corn syrup and our engines with ethanol, neither of which is doing us much good.
All over Vermont right now, dairy farmers and carefully and knowledgeably balancing their cows’ rations so the microorganisms in their stomachs will do the best possible job of turning otherwise indigestible substances into milk. Our cows are getting more consideration in that regard that we are.