(NaturalNews) Two new studies have added more reason for concern that high-fructose corn syrup causes significantly more harm to the body than its mere sugar content would suggest.
High-fructose corn syrup contains 55 percent fructose and 45 percent glucose. In contrast, table sugar (also known as sucrose) contains a 50-50 split.
In the first study, published in the journal Pharmacology, Biochemistry and Behavior, researchers from Princeton University found that rats consuming high fructose corn syrup gained more weight and developed more cardiovascular risk factors than rats consuming equivalent amounts of sucrose.
"Some people have claimed that high-fructose corn syrup is no different than other sweeteners when it comes to weight gain and obesity, but our results make it clear that this just isn't true, " researcher Bart Hoebel said.
Hoebel and colleagues fed two groups of rats an identical diet, supplemented with one of two sweetened beverages. One beverage consisted of a sucrose solution in concentrations similar to those found in many sweetened beverages. The other consisted of a high-fructose corn syrup solution at roughly half the concentration of a typical soda. The researchers found that the rats consuming the corn syrup solution gained significantly more weight than the rats consuming the sucrose solution.
In a followup experiment, the researchers compared metabolic changes in rats fed only rat chow with rats fed chow plus a high-fructose corn syrup solution. All the rats consumed the same amount of calories.
After six months, the rats in the corn syrup group had gained 48 percent more weight. They also underwent an increase in fat deposition (especially in the abdomen) and a drop in circulating triglycerides. These changes are consistent with metabolic syndrome, a cluster of symptoms that predispose humans to cardiovascular disease and diabetes.
Every rat consuming high-fructose corn syrup became obese. In contrast, rats fed a high-fat diet did not become obese in all cases.
Another study, conducted by Duke University researchers, once again implicates high-fructose corn syrup in a heightened risk of liver damage.
Previous research has suggested that large amounts of fructose liver in the same way as excessive alcohol consumption. Another study linked high-fructose corn syrup specifically with a form of liver scarring known as non-alcoholic fatty liver disease (NAFLD).
The new study, published in the Journal of Hepatology, found that high-fructose corn syrup worsened the effects of NAFLD.
"We found that increased consumption of high fructose corn syrup was associated with scarring in the liver ... among patients with NAFLD," researcher Manal Abdelmalek said.
The researchers analyzed the diets and livers of 427 adults with NAFLD, and found that only 19 percent of them never consumed fructose-containing beverages. In contrast, 52 percent of participants had between one and six servings of a fructose-containing beverage per week, while another 29 percent had at least one serving per day. The higher patients' fructose intake, the worse the scarring of their livers.
"We have identified an environmental risk factor that may contribute to the metabolic syndrome of insulin resistance and the complications of the metabolic syndrome, including liver injury," Abdelmalek said.
Abdelmalek noted that NAFLD is a severe problem that cannot be treated and may lead in some cases to liver cancer, liver failure and a need for liver transplant.
Researchers are still unsure why high-fructose corn syrup appears to damage the body more than its extra 5 percent fructose content would suggest. Some have hypothesized that the negative effects come from the massive quantities in which it is consumed -- high-fructose corn syrup is found in nearly all processed foods.
Other researchers have observed that beverages made with high-fructose corn syrup contain high levels of reactive carbonyls, which can damage cells. Still others have noted that the fructose in high-fructose corn syrup is chemically unbonded and thus spreads through the body more freely than the fructose in table sugar.