A new study from the University of Waterloo in Waterloo, Ontario, has determined that noninvasive stimulation of specific areas of the brain may help reduce food cravings for so-called “appetitive foods” -those high-calorie, high-fat foods like potato chips, cookies and ice-cream we often reach for to quell that snacking urge.
Researchers from Waterloo’s Department of Kinesiology conducted a meta-analysis of various studies devoted to investigating the effects of brain stimulation of the section of the brain called the dorsolateral prefrontal cortex (dlPFC), said to be important for self-control particularly with reference to eating behaviour and dietary restraint. The study’s authors found that in single-session laboratory settings, stimulation of the dlPFC did have an effect on cravings for snack foods.
“Limiting the consumption of calorie-dense foods is essential for preventing the onset of many chronic diseases, as the overconsumption of such foods can increase the risk for excessive adiposity and disease-mediating metabolic conditions,” say the study’s authors, whose work appears in the scientific journal Psychosomatic Medicine. “[Our findings] support a causal effect of neuromodulation of the dlPFC on food cravings.”
The medical history of using electrical current to stimulate the brain is a long one, dating back to the Roman Empire where physicians treated illnesses such as headache and gout by placing electric torpedo fish directly on the affected area, through to the 20th century and the rise of electroconvulsive therapy as a commonly-prescribed treatment for mental illnesses like schizophrenia.
Modern research in cognitive neuroscience has found evidence that stimulating the brain withelectrodes placed on the scalp -called transcranial direct current stimulation (tDCS)- may have a variety of practical applications ranging from helping to relieve symptoms of anxiety and depression to improving memory, creativity and focus. Hence the recent rise in home-use tDCS devices -either store-bought or (gulp!) home-made- complete with headbands, electrodes and, of course, a power source.
“There are a variety of different devices, however the simplest and most common approach is to place two saline soaked sponges on the scalp and run a weak electrical current through them,” says Dr. Michael D. Fox of Beth Israel Deaconess Medical Center in Boston. “It can be done at home with a couple of sponges and a 9 volt battery, which is why DIY tDCS exists. Whether it should be done is a different question.”
Dr. Fox is one of a group of neuroscientists who recently published an open letter warning against DIY brain stimulation. The scientists argue that although there is preliminary evidence that using tDCS can produce positive results, just as so much about the inner workings of the brain has yet to be understood, the practice of tDCS and its impact on brain functioning are still relative unknowns.
“Outcomes of tDCS can be unpredictable,” says Dr. Rachel Wurzman of the University of Pennsylvania and co-author of the letter. “And we know that in some cases tDCS use can actually make brain function worse.”
Signed by 39 researchers, the letter intones the scientific reasons supporting caution in the use of home use tDCS kits. The letter appears in the journal Annals of Neurology.
More Cantech Science