Robert Palmer released his hit single “Addicted to Love” in 1986, but if he really wanted to capture the mood of the next 25 years he should have called it “Addicted to Food.” Since 1980, worldwide obesity rates have more than doubled, and scientists continue to look for medical and behavioral clues to help explain this epidemic.
The latest research, presented this week at the Canadian Neuroscience Meeting 2013, shows that high-fructose corn syrup can cause behavioral reactions in rats similar to those produced by drugs like cocaine.
Addiction expert Francesco Leri, an associate professor of neuroscience and applied cognitive science at the University of Guelph in Ontario, Canada, suggests that some people may be addicted to food just as some are addicted to drugs. This food addiction could explain, at least in part, the global increase in obesity.
“We have evidence in laboratory animals of a shared vulnerability to develop preferences for sweet foods and for cocaine,” Leri said in an interview with Healthline. “The advantage of using animals is that you get a good sense of the biology of the behavior without interference from culture standards, personal beliefs, economic advantages, etc.”
Leri investigated the behavioral, chemical, and neurobiological responses of rats to unnaturally high concentrations of sugar, fats, and taste enhancers, such as high-fructose corn syrup and foods like Oreo cookies.
While an increase in the availability of processed, sugary, and fatty foods could partly explain the high incidence of obesity around the world, Leri argues that simple availability does not explain why some people are obese and others are not.
He says that both availability and vulnerability are key. Surveys of cocaine consumption, for example, show that though many individuals try the drug, only a small percentage of them become addicted.
“All of us have access to substances including alcohol, yet most of us are not alcoholics,” Leri said. “A lot of us are developing weight problems, but not all of us are developing food addictions. We continue to find good evidence that some people’s risks are more behavioral than nutritional and that once you get into the cycle, it can stick with you for the rest of your life.”
Leri is not alone in his research. Julia Ross, author of The Diet Cure, writes in her book that sugar can be four times more addictive than cocaine, based on evidence from a 2007 study conducted at the University of Bordeaux.
For their part, the Corn Refiner's Association, which produces high-fructose corn syrup, challenged the validity of Leri's findings.
“There remains no credible scientific evidence to suggest that caloric sweeteners, such as sugar and high fructose corn syrup (HFCS), are addictive to humans in general," said John W. Bode, President and C.E.O. of the Corn Refiners Association. "One of the main weaknesses of the research conducted by Dr. Francesco Leri, like most research seeking to demonize HFCS and other caloric sweeteners, is they are often conducted on animals, such as rats, in scenarios not likely found in the real world experienced by humans."
Whether sugar is the culprit or not, the World Health Organization uses the term "globesity" to qualify this epidemic, which is present in all parts of the globe, not just in industrialized societies. Obesity poses major health risks to sufferers, including diabetes, cardiovascular diseases, hypertension, stroke, and certain forms of cancer.