Can sugar be addictive?
over whether sugar is an addictive substance or not.
The report comes on the back of growing suggestions that food components such as sugar or fat may have some similarities to addictive drugs.
In medical terms, a substance is addictive if it induces a pleasant state or relieves distress; leads to adaptive changes in the brain that trigger tolerance, physical dependence and uncontrollable cravings; and causes dependence to such an extent that abstaining is difficult.
But Cynthia Bartok, associate director for the Center for Childhood Obesity Research in Penn State's College of Health and Human Development said that despite reports of people who claim to be addicted to sugar, modern science has yet to provide conclusive proof of this.
Some scientists however claim to have found the response to sugar consumption in rats as very similar to responses to drugs such as heroin and cocaine. What is clear is that when humans and rats eat sweets, their brain levels of dopamine - a neurotransmitter that regulates reward and is at the heart of many addictive behaviours - increases.
In addition, Penn State's Lisa Duchene points out that a 2002 study from Princeton University found that rats deprived of food for 12 hours then given food and sugar-water tend to binge on the drink. This research suggests that rats' brain systems change in response to sugar.
But according to Rebecca L. Corwin, associate professor in nutritional sciences at Penn State, proof of sugar addiction remains inconclusive. She pointed out that sugar formed part of a healthy diet, and that human brains depend on glucose to function properly.
In addition, some academics have questioned whether sugar even leads to hyperactivity. An earlier study from the University of California Berkeley concluded that when chocolate and sugar are consumed, they "do not promote hyperactivity in most children."
Most likely, the authors said, "it is some special event surrounding the eating of a lot of sugar and/or chocolate that gets children excited."
The report from Penn State shows that debate on this subject is lively, and suggests that further research on this matter is very likely.