Food as an Addiction

I was struck by the solid information presented in a recent review article in the CMAJ (Canadian Medical Association Journal). Dr Valerie Taylor and colleagues were summarizing one of the driving forces in the overconsumption of food. They felt that when overeating becomes compulsive it is often classified as a "food” addiction: a label which is both clinically and scientifically controversial.

However, it is important to understand the science behind food as an addiction, since it may help us to feel less guilty and it may also help guide us to solutions.

Traditionally, the term "addiction” was applied solely to the abuse of drugs that activate the brain's mesolimbic reward pathways. In recent years, a broader conceptualization of addiction has emerged, and the term now includes so-called ‘behavioural addictions.' This change has been based on research showing that the mesolimbic reward system is also activated by pleasurable behavioural activities. In fact, imaging studies have shown that specific areas of the mesolimbic system, such as the caudate nucleus, the hippocampus and the insula, are activated both by drugs and by food. Both also cause the release of striatal dopamine, a neurotransmitter that is an integral part of the reward system. Endogenous (ones that are naturally occurring in our brain), are another group of players in the reward pathways, and are also activated by drugs and by food (especially sweet foods) whereas the opioid blocker naltrexone has been shown to reduce cravings for both. Also if we block the endocannabinoid receptors (marijuana receptors) in the brain we can treat the cravings for some foods.

In an attempt to explain the motivation for some cases of compulsive overeating, researchers have proposed that highly palatable foods, such as those that are sweet, salty or high in fat, have the potential for abuse in a manner similar to conventional drugs. From an evolutionary perspective, it would have been highly adaptive for the consumption of food to be rewarding, especially in the case of foods rich in fat and sugar since they can be rapidly converted into energy. Thus, the reward pathway evolved to reinforce the motivation to engage in naturally rewarding behaviours such as eating, thereby promoting survival in times of famine. Unfortunately, over the past few generations food technologies have allowed the creation of foods that are calorie-dense, high-fat and high sugar (carbohydrate). Vulnerable individuals will misuse food.

Vulnerability may also stem from various personality traits. For example, obese individuals tend to be more sensitive to reward and punishment and to display more impulsive behaviours. For these individuals, the forces driving food consumption are likely to go beyond physiologic hunger. Highly palatable foods may produce pleasure and reduce pain in a manner similar to other addictive substances. We all know we can self medicate with food in response to depression, anxiety, loneliness, boredom, anger and interpersonal conflict.

As a society we must stop the ‘blame' mentality that is applied to individuals with excess weight. It is a physiologic disorder. Eating behaviours are very complicated and sometimes the driving mechanism will feel beyond our control (as evidenced by the research above.)

Can we do anything? Certainly we can recognize that certain foods are triggers, and our desire for them is not abnormal. Do not feel guilty if you can't get the idea of a cookie or ice cream or potato chips out of your head. It is not a sign of weakness; maybe you can think of this as the opioid centers of your brain being overactive. At that point, try to find solutions. Remove any and all trigger foods from the house. (Right now). Do something to physically or mentally remove yourself from the situation. Watch TV. Work on the computer. Go upstairs and read a book. Phone a friend. Go for a walk, or drive. We must try to settle that area of the brain down until the urge disappears.

It is very hard work, but you can do it. Just keep trying and don't ever give up!

Dr. Doug