Food and Addiction
Sunday, April 29, 2012
I just read an interesting article in Nutrition Action Health Letter, a monthly newsletter published by the Center for Science in the Public Interest (www.cspinet.org). It explains the science behind the idea that certain foods can be addictive in terms that a non-scientist can understand.
The latest research is based on imaging studies of the brain, showing how the brain responds to certain foods that are high in fat and sugar. It has to do with how a neurotransmitter called dopamine works. Dopamine is what "motivates" us to eat and engage in other rewarding behaviors. One of the findings is that people who are obese don't have as many dopamine receptors in the target area of the brain, so they don't get as much of a reward response from eating certain foods, and need more to be satisfied. There is also evidence that the process of overeating itself further dampens the dopamine response making obese subjects even more likely to overeat. And there is more: apparently heavier subjects also respond differently to images of certain foods, a pattern also seen in drug abusers who are exposed to drug paraphernalia, or to people they have taken drugs with in the past. What makes this more worrisome is that, unlike images of drug paraphernalia, food images are the subject of sophisticated marketing techniques, and it's hard to get away from them.
The article itself is only available by subscription to the newsletter (CSPI does not accept advertisements, so they depend on subscriptions for revenue), but the science it's based on is published elsewhere, so you may have access to it through other sources. There is also a lot of additional information on this topic available at the Rudd Center for Food Policy and Obesity at Yale University (www.yaleruddcenter.org), including podcasts and other materials from a 2009 Food Addiction Summit.
I've always been interested in this topic, because I recognize that I am sensitive to the addictive qualities of foods like chocolate. Fortunately, there are some things you can do to counteract the problem. Here is CSPI's list:
1) Avoid mindless eating;
2) Beware of cues;
3) Avoid the troublemakers;
4) Eat healthy foods;
5) Distract yourself;
6) Beware of stress, and finally,
Most of these tips are intuitively obvious, but interestingly, studies have shown that exercise increases dopamine receptors (meaning you should get more satisfaction from a given amount of food), and it also increases activity in the prefrontal cortex, which is where conscious decisions are made. To quote CSPI: "And guess what? It doesn't have to be extreme activity. Brisk walking is good enough."
With that, I'm going for a walk (or a bike ride). How about you?