Our brains can learn to love healthy foods
Boston researchers think it may be possible to train the brain to prefer healthy low-calorie foods over unhealthy higher-calorie foods.
"We don't start out in life loving French fries and hating, for example, whole wheat pasta," says Susan Roberts, the senior author of a study by scientists at the Jean Mayer USDA Human Nutrition Research Center on Aging (USDA HNRCA) at Tufts University and at Massachusetts General Hospital.
"This conditioning happens over time in response to eating – repeatedly! - what is out there in the toxic food environment."
Scientists have suspected that, once unhealthy food addiction circuits are established, they may be hard or impossible to reverse. To find out whether the brain can be re-trained to support healthy food choices, Roberts and colleagues studied the reward system in 13 overweight and obese men and women, eight of whom were participants in a weight loss program designed by Tufts University researchers and five who were in a control group and not enrolled in the program.
Both groups were given MRI brain scans at the beginning and end of a six-month period. The scans of those people in the weight loss program revealed changes in areas of the brain reward centre associated with learning and addiction. After six months, this area had increased sensitivity to healthy, lower-calorie foods and decreased sensitivity to the unhealthy higher-calorie foods.
"The weight loss program is specifically designed to change how people react to different foods, and our study shows those who participated in it had an increased desire for healthier foods along with a decreased preference for unhealthy foods, the combined effects of which are probably critical for sustainable weight control," says co-author Sai Krupa Das.
Co-corresponding author Thilo Deckersbach, a psychologist at Massachusetts General Hospital, says:
We show here that it is possible to shift preferences from unhealthy food to healthy food without surgery, and that MRI is an important technique for exploring the brain's role in food cues.
The study is published in Nutrition & Diabetes.