Dangers of High Fructose Corn Syrup (HFCS)
Major controversy surrounds HFCS with respect to its effects on metabolism and health. Several studies suggest a clear-cut correlation between regular HFCS consumption and the obesity epidemic sweeping America, along with raising associated health risks such as diabetes and heart disease. In 2004, scientists from the Pennington Biomedical Research Center, Louisiana State University investigated the connection between HFCS intake and obesity. They reported that HFCS consumption had increased by more than 1,000% between 1970 and 1990, much more than any other food - and estimated that average HFCS consumption for the top 20% of consumers of caloric sweeteners was over 300 kcal daily. They also pointed out that this increased HFCS consumption mirrored the rapid increase in obesity, suggesting that the digestion, absorption and metabolism of fructose were significantly different from those of glucose.
In the liver, unbound fructose in HFCS is known to be metabolized into triglycerides (blood fats) which are stored in the liver and abdomen, increasing the risk of heart disease and stroke. Unlike glucose, fructose does not stimulate insulin secretion or enhance leptin production, both of which act to regulate food intake and body weight - suggesting that dietary fructose may trigger caloric overconsumption, contributing to weight gain.
In a study published in the American Journal of Clinical Nutrition, scientists at the University of Lausanne in Switzerland studied the effect of fructose on children predisposed to diabetes. A total of 24 healthy children were included, of whom sixteen had diabetic parents and eight did not. The children with diabetic parents began the study with higher levels of triglycerides and lower levels of insulin sensitivity. At the start of the study, all of them consumed a normal diet. Halfway through, their diets were switched so that 35% of their calories came from HFCS. Just 7 days of HFCS consumption increased harmful triglyceride levels by 110% in the children of diabetics and by over 50% in children with healthy parents. Not only that, their insulin sensitivity was significantly decreased and all of them had more fatty deposits in their liver, increasing their risk for heart disease.
When sugar enters the liver, it is stored, burned or turned into fat. But fructose is different in that it is directly converted to triglycerides, elevating the risk of heart disease. For example, researchers in Philadelphia looked at how high-fructose drinks affected two groups of obese people. One group enjoyed a high fructose drink with dinner, while the other group had a glucose-sweetened drink with dinner. At the end of the study, triglyceride levels in the high fructose group were a striking 200% percent higher than in the glucose group.
Studies also show that fructose blocks signals from three critical hormones - insulin, ghrelin, and leptin - which control blood sugar levels, appetite and fat storage and indicate how much to eat and when to stop eating. They also tell the liver whether to burn or store glucose. Over-eating is one consequence of these signals being blocked.
Two further studies from the Department of Psychology and the Princeton Neuroscience Institute investigated the link between HFCS consumption and obesity. In the first study, male rats given water sweetened with HFCS gained much more weight than those that received water sweetened with table sugar, or sucrose, along with their normal diet of rat chow. In the second experiment - the first long-term study of the effects of HFCS consumption on obesity in lab animals - scientists monitored weight gain, body fat and triglyceride levels in rats with access to HFCS over a period of six months. Compared to animals eating only rat chow, these rats showed signs of a dangerous condition known in humans as the metabolic syndrome, including abnormal weight gain, significant increases in circulating triglycerides and fat deposition, especially visceral fat around the belly. Male rats with access to high-fructose corn syrup gained 48% more weight than those eating a normal diet.
So when you're next at the grocery store, check out the ingredients on the label of food items you're about to place in your cart. You may have to give up soda altogether, but you can most probably find a HFCS-free substitute for most other foods.
You could also avoid processed foods - instead, consume fresh, low-glycemic veggies and fruits, natural, grass-fed meats, free-range poultry, cage-free eggs and cold-water wild fish. Indulge yourself with natural foods like organic yogurt and unsalted nuts like walnuts and almonds. And if you need a sweetener, choose organic raw honey.