June 27, 2013
Food Addiction Often Begins With Bad Carbohydrates
Michael Harper for redOrbit.com - Your Universe Online
One week after the American Medical Association (AMA) declared obesity as a disease, one doctor is suggesting an addiction to food might be a very real thing.
Dr. David Ludwig with Boston Children's Hospital admits that the suggestion of a food addiction is very controversial. After all, humans require food to live but don't require other addictive substances, such as alcohol or nicotine to survive.
Determined to understand the effects food has on the brain, Dr. Ludwig recruited 12 obese and overweight men and subjected them to an MRI scan after drinking milkshakes. The researcher pinpoints carbohydrates found in processed food as a potentially addictive substance, saying the same area of the brain associated with addiction lights up in the presence of these carbs. This research also helps explain why fast food and other processed foods don't satisfy us as well as healthier options.
The study is published in the American Journal of Clinical Nutrition.
"We showed for the first time that refined carbohydrates can trigger food cravings many hours later, not through psychological mechanisms – a favorite food is just so tasty, you need to keep eating – but through biological effects," said Dr. Ludwig in a statement.
The 12 obese men observed in this study were given milkshakes to drink, each with the same amount of calories, protein, carbohydrates and sugar. Some of the men, however, received a milkshake which was made with a processed carbohydrate with a higher glycemic index. These "bad" carbs are found in white breads, white rices and other processed foods. They're also more quickly transformed into sugar in the blood stream.
After taking blood samples from the volunteers, the researchers also scanned their brains with a real-time MRI machine to observe which parts of their brain were active in the four hours after they consumed their shakes. The blood samples revealed the men who had consumed the high glycemic carbs experienced a surge in blood sugar levels; a reaction they expected. Not long after, however, their levels crashed and left them feeling hungry again. The brain scans revealed something quite interesting as well.
According to Dr. Ludwig, the bad carbs activated the nucleus accumbens, a portion of the brain that is also triggered by addictive drugs and dangerous behavior.
"Our research suggests that some of these foods might hijack the reward systems of the brain and produce symptoms related to addiction," said Dr. Ludwig.
This kind of reaction in the brain could even be responsible for the difficulty obese people have in losing weight. For instance, if bad carbs trigger this portion of the brain and leave people feeling hungry sooner, it could be hard for them to ignore the impulses and steer away from the bad food.
"These results suggest that highly processed carbohydrates trigger food cravings for many hours after consumption independent of calories or tastiness, and that limiting these foods could help people avoid over-eating," said Dr. Ludwig, as cited by Time's Alexandra Sifferlin.
Since overweight and obese people often over eat, restricting the intake of these carbs could be the key in losing weight and keeping it off.