Why do we crave chocolate so much? I consulted a professor of psychology and neuroscience
, Dr. Amy Jo Stavnezer, to help us understand why we desire chocolate so much (just in time for Valentine's Day!).
Dr. Albers: On a biological level, why do we crave chocolate?
Professor Stavnezer: We crave chocolate because it is good! It tastes good. It smells good. It feels good when it melts on our tongue. And all of those ‘feelings’ are the result of our brain releasing chemicals in response to each chocolate experience. The experience of eating chocolate results in feel good neurotransmitters (mainly dopamine) being released in particular brain regions (frontal lobe, hippocampus and hypothalamus—definitions a bit later).
Dopamine is released when you experience anything that you enjoy—sex, laughing, or watching your favorite Olympian claim the gold. This reward circuit is partially hard-wired by genetics, but it learns, changes and responds to your specific preferences based on your life experiences. This malleability of the brain is what makes each of us unique. In fact, there are supposedly people in the world who do not like chocolate.
By simply using one neurotransmitter system to associate rewards with actions, an efficient and powerful brain network evolved so that a positive outcome would be repeated. The dopamine signal sent through the reward circuit brings about positive feelings and assessments of the situation in the frontal lobe (just behind your eyes), creates a memory of the experience including where, who, what and why and links that to the positive experiences via the hippocampus (about an inch inside of each ear), and when food is involved, the hypothalamus (a few inches above the roof of your mouth) gathers information about the caloric and nutrient content for future hunger and satiety signals.
It was originally thought that chocolate contained compounds that could activate this dopamine system directly (like cigarettes and cocaine do). Chocolate does contain theobromine that can increase heart rate and bring about feelings of arousal, caffeine which can make us feel awake and increase our ability to work and focus, and fat and sugar which are preferred food sources for humans because they are calorie dense. However, elegant experiments in which the components of chocolate were separated out indicated that just ingesting the chemicals in chocolate without the mouth-feel and taste does not decrease craving.
Dr. Albers: Tell us about some interesting chocolate research.
Professor Stavnezer: Dr. Paul Rozin, of the University of Pennsylvania, is a leader in the field of food choice and was the author of a 1994 study that I alluded to earlier. He wanted to know which parts of chocolate could quench a craving. The researchers gave chocolate cravers a Hershey bar (all chocolate components: mouth-feel, fat, sugar, cocoa compounds), capsules filled with Hershey’s cocoa powder to equal that in a bar (only the compounds), a white chocolate confection (same sugar and cocoa butter as the bar, but no compounds), and a white chocolate bar combined with the cocoa powder capsules (all chocolate components, but separated) to eat at separate cravings in a specified order. The participants then rated their decrease in craving 90 minutes later (amount of time necessary for theobromine and caffeine to become bioactive).
Eating the Hershey bar resulted in a 61% decrease in craving (the largest decrease), the white chocolate alone a 42% decrease, and the cocoa capsules alone a 16% decrease—clearly indicating that the decrease in craving is driven by all components of chocolate being taken together, and not simply by the biological effects of the chemicals. Though we still don’t know what makes chocolate so enticing, as cacao has hundreds of different chemicals and compounds that imbue it with a loveliness of aroma, flavor and texture. As a group of Australian authors stated in 2006, chocolate is “the perfect orosensory experience to seduce the palate.”
Dr. Albers: So what aspect of the chocolate experience causes the release of dopamine?
Professor Stavnezer: To answer that question we have to recall what dopamine does: it helps us to remember positive experiences that will promote our survival, and one other thing…Once we have learned a positive association with, say, chocolate, dopamine gives us a little surge of anticipation when we walk by the cabinet, when we smell it or sometimes even if we just imagine it, hence the feeling of craving. If you eat chocolate and enjoy it, then every time you eat it you strengthen your dopamine response, and the behavioral pattern necessary to get that feeling back again. You might not remember the first time you loved chocolate, but your brain does, thanks to the hippocampus. You probably did not have to learn to like chocolate, the sensory experience is enjoyed on an innate, biological level, but it is likely that you received chocolate as a treat, reward, or for holidays, especially if you are American.
Throughout our lives we learn that chocolate is positive, family, friends and the media make this clear. It’s February, the month of cupid and chocolate—and we are given a clear message (especially women) that chocolate signifies love. Now that our dopamine system doesn’t have to be tuned in to poisonous berries, it can turn these messages and experiences into memories likely to promote survival. From an evolutionary perspective, love leads to sex, sex leads to offspring and offspring lead to passing on our genes, which, in the end, equals survival.
Dr. Albers: How do our emotions play into cravings?
Professor Stavnezer: It’s easy to blame cravings, binges, or crashes on an overwrought emotional system. But it’s not quite that simple; emotions are just one part of what our brain is doing at any given time. There are associated regions in our brain known as the “Central Executive” (mostly frontal lobe) that are constantly monitoring and responding to both internal and external experiences. But just like a muscle can become fatigued, the central executive can have too much to deal with from time to time, causing a bit of a failure. Let me be clear here, this is not the same as multi-tasking (which by the way we are also not good at), it’s simply a limitation on how much information our brain can hold online for immediate use. The central executive deals with spatial information, language based information (both read, heard and spoken) and with fitting all of these experiences together with our memories that already exist.
Researchers have found that ‘stressing’ this cognitive system, by requiring people to remember lots of numbers at one time for example, leads to food choices that are higher in calories and more impulsive. This occurs for two reasons, one is that our brain consumes huge amounts of glucose, so when it is overworked it needs more energy and secondly, when our central executive is overwhelmed with the cognitive load, it can not allocate more processing space to thinking through a food choice. And just to let you know, the opposite is also true, if our emotional system is ‘stressed’ with graphic images or emotional anecdotes, we perform more poorly on cognitive tasks.
Dr. Albers: What do we do with these cravings?
Professor Stavnezer: Do as Dr. Albers has suggested many times, make your decisions about food with as clear a mind as possible. Take a few minutes to decompress from whatever you were working on or thinking about before choosing your meal, or giving into a craving. Of course that will not make everything go away, but it will allow the less important items that take up mental space to drop away, leaving more space for an attention focused decision about food.
If you choose chocolate, taking your time with it enhances your positive experience because all of your attention is focused, and you are able to lengthen the amount of time that you experience pleasure. Talking yourself out of a craving by choosing another food, leaving the immediate area of the chocolate, meditating or exercising also works because our brain chemistry is ever changing.
If you can fulfill a need for food with an apple, and get a satisfying crunch with sweet juice to follow, there is a good chance you will get some feel good chemicals flowing in your brain. If you can take 10 minutes for a brisk walk, you will have lots of chemical changes in your brain, all very positive, and all very rewarding—with no food intake at all.
Will any of this change our cravings, probably not. Maybe, in the end, we just crave chocolate because Linnaeus was dead-on when he named the plant Theobroma Cacao, or “Food of the Gods”.
Thank you to Dr. Amy Jo Stavnezer for helping us understand why chocolate is a food we crave on so many different levels!
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Dr. Susan Albers is a psychologist at the Cleveland Clinic and author six books on mindful eating (including one called "But I Deserve This Chocolate). Join her Mindful Eating Chocolate Challenge for the month of February via her facebook page. www.eatq.com