Food is a drug

It’s true, food is an addiction.. and the higher the fat and sugar content of the food, the more addicting it is.

Did you ever say to yourself “I will just have a small piece of  ________ (cheesecake, ice cream, cake… fill in the blank!)” and end up eating way more than you wanted to?  Did you ever notice that when you “fall off the wagon” of eating healthy, it’s harder to get back to eating healthy than it is to give into junk food?

A recent review article in the journal Frontiers in Neuroendocrinology by Johan Alsio, Ph.D. and others illustrates how much our bodies are made for holding onto fat by way of brain changes, variations in hormone levels, and molecular adaptations during overeating.

In our society, we tend to eat not only from hunger, but from food cravings  even at the risk of gaining weight, developing diabetes, and increasing our cholesterol levels – if left unchecked making us susceptible to disorders and disease.  So, why can’t we stop the bad cycle of indulging too much?

Apparently the link between drug addiction and food addiction is quite closer than we might think because both activate pathways in the brain that affect levels of the neurotransmitter dopamine (aka – the reward system).   Get this: the same changes are seen in this pathway in both obese individuals and those that are addicted to cocaine, meth, and heroin!    The higher preference there is for sugar correlated to a bigger preference for alcohol, cocaine and speed in rodent models.

Food also acts like a drug in that the more you are exposed to higher fat and higher sugar foods, the more your body will crave them (a ‘feed-forward’ system – ironic, right?).  The higher your weight, the bigger the craving for high fat and high sugar foods.   So you might wonder what happens if we actively choose to eat super healthy and stay away from junk (easier said than done considering we have pizza, burgers, and ice cream waiting at the back door).  Even if you can withstand the higher cravings during ‘dieting’ – this usually leads to higher and longer periods of cravings, making it much easier to give in.  Sometimes that salad just doesn’t do it for us, but those steak burritos across the street…..they just sound so yummy :)   In studies done with animals, the longer time period of abstinence from high fat and high sugar foods caused their sugar cravings to increase, they had higher anxiety levels, they were more susceptible and higher tendency to show food-seeking behavior – you can see how this can become a never-ending cycle – like Lindsay Lohan’s frequent visits to rehab.  These effects create the yo-yo dieting that is common in our society.

Similar to drug use, there are also withdrawal symptoms after abstaining from high fat/high sugar foods – emotionalism, anxiety, cravings (the neurological symptoms), but also physical symptoms like teeth chattering and tremors (shown in rodents).  They mental and physical symptoms are attributed to changes that happen in the brain after exposure to these foods. One that I mentioned before: dopamine levels change and the body’s response to it are altered, but also changes in the receptors for endocannabinoids (think, marijuana), and changes in receptors for opioids.  The more we eat junk food, the more we want it – risking health issues and obesity (and get this: the more obese a person is, the less likely they are to become addicted to drugs, because food fills that void).   The changes that happen in the brain seem  permanent; this is why many people gain the weight back that they lost years ago (so relapsing to bad behaviors doesn’t just happen after short-term healthy eating).

Evolutionarily, seeking out high fat and high sugar foods was crucial in times when food wasn’t readily available… so the problem is that while we have food everywhere now, our bodies haven’t really caught up.

Questions to think about:

1) Can we override the signals in the brain that tell us to seek more food?

2) How well does cognitive behavioral therapy work for overweight and obese patients?

3) To what extent can exercise reverse changes that happen in the brain and body that increase the drive to eat?

About hollyrichendrferphd

Neuroscientist at Brown University: Studying effects of neurotoxicants on behavior and brain development

Posted on March 8, 2012, in Addiction, Diet/Obesity. Bookmark the permalink. 1 Comment.

  1. @question #3: Further, could the positive relationship between neurogenesis and exercise play a role in balancing eating behavior? -Alyssa

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