Here comes science!

[Ed.:  I would like to heartily welcome Dr. D. Gustibus to and thank the good doctor for this, and hopefully many more insightful and entertaining articles to come. -Mr. Carnegie]


My near and dear friend Mr. Carnegie asked me if I would write the occasional post on this fine blog, to which I agreed. In keeping with the general theme of this blog and given my background (PhD in psychology), my posts will focus largely on the intersection of food and science. Eating and drinking are activities we engage in every day yet I imagine many of us don’t think about the hows and whens and whys and whats of how and when and why and what we eat…or with whom 🙂

Fortunately, there are a great many people out there who make it their business to delve into these topics and I intend to share some of these fascinating insights with you, the fine readers of this blog.

Let’s start off with a “heartwarming” topic: Comfort food. The term is widely used and, I imagine, familiar to most. But, is comfort food really “comforting”? That is, why do we so often seek out those foods that are high in fat, sugar and starch?

Some yummy lookin' ribs on the smoker

Comfort food seems to have gained more traction in the culinary world as of late. For example, consider the proliferation of cupcake shops over the last few years: A quick search for “cupcake shops” in Toronto on Yelp yields over 120 results. Now, although this particular foodstuff may have reached its saturation point, some argue that the trend of comfort food in restaurants and shops may continue into the current year.

But why? The reasons are likely to found in the intersection of economics, biology and psychology. (An excellent piece on the intersection of the last two factors may be found here.)

A fact which I’m sure has escaped no one is the painful one-too punch of a continued relatively poor economy and increase in food prices. With less money to spend and with lower purchasing power, people are turning to more cost-effective food options. For example, Forbes magazine reported that over the course of the economic downturn, McDonald’s has experienced increased sales. Although McDonald’s, like other fast food outlets, does sell salads, the increase in McDonald’s bottom line has come from sales of their “core menu” of burgers, fries and pop. As anyone who has seen the excellent Food, Inc. can attest to, when compared to more healthier options available at a supermarket, the cost and convenience of a burgers-and-fries laden value meal make the latter choice highly appealing.

This is not to say that it is only those who are most affected by the economy who are turning to comfort food. As mentioned above, high-end cupcake shops (e.g., one cupcake shop in Toronto lists cupcakes at $2.65 each) and similarly high-end barbecue places are popular. Similarly, meat-heavy Korean BBQ is tipped to be a food trend for 2011. Starbucks has been selling high fat, high sugar indulgences for years now. But what is it about these particular foods that make them so popular? It is here where biology and psychology come into play.

Comfort food, which is laden with fat, sugar and starch, is calorically rich. Evolutionary psychologists argue that as a species we are unaccustomed to living in environments where calorically rich foods were readily available. As a result, we have developed a preference for foods that are high in fat, sugar and starch. There is a sensible, self-preserving logic to this sort of mechanism: If we are not sure when we are likely to encounter such foods in the future, then we should consume them when the opportunity presents itself.

So, comfort food is readily available and taps into a deep-seated biological mechanism to consume high-calorie food. These factors alone would seem to explain the longstanding presence and appeal of comfort food. But does comfort food actually improve our mood? The current answer appears to be a tentative “yes”.

If comfort food really is comforting, one might think it should improve our ability to withstand pain or unpleasant situations. This notion turned out to be the case, both in rats and humans. A study in the Proceedings of the National Academy of Sciences LINK reported that when rats were subjected to environmental stressors, specifically being in a cold environment for a prolonged period of time, they consumed increased amounts of lard and sucrose. In turn, levels of stress-related hormones in their blood decreased. Similarly, research on humans published in the journal Physiology and Behavior LINK showed that, compared to those who ate a meal of low-fat, high-carbohyrdrate pancakes, people who ate a meal of full-fat pancakes reported less pain while keeping their dominant hand in a bowl of ice-cold water. In addition, recent research on eating habits and stress found that 21% of individuals who ate at a fast food restaurant in the last week reported increased feelings of stress, whereas 13% of those who did not eat a fast food restaurant reported increased stress. Of course, most of us (I imagine) aren’t submersing our hands in very cold water on a daily basis, but these results do suggest that there is something about eating a fatty, carb-rich meal that yields an analgesic effect.

But is it just the nutritional content of these foods that help us deal with stressful events? That is, what is the role of the actual smelling, eating and tasting experience in influencing our mood? We certainly see advertisers present these foods (and many others) as luxurious not only in taste but as an indulging, luxurious experiences. See here and here as examples. Even experts on such topics as coffee, chocolate and wine talk about the “nose”, “bouquet”, or “mouthfeel” of their comestibles. Researchers talk about this mechanism as the “oro-sensory component”. This component does appear to play a role in the pleasing effects of comfort food. The author of the aforementioned Physiology and Behavior article found that when subjects were fed with tubes rather than by eating via the conventional manner, the analgesic effects of eating the high-fat meal disappeared. These results have been repeated on numerous occasions (see here and here). This link between the mouth and brain may explain the pleasing feelings of eating chocolate or other such foods.

However, the exact mechanism explaining why comfort food is so comforting is up for debate. For some, the oro-sensory pathway is the driving force behind these pleasant feelings. More specifically, the hormones that are released after eating a carbohydrate- or fat-rich meal cause the changes in mood. These hormones may include endorphins, the built-in, pain relieving compounds we all possess, which may interact with the opiate, “pleasure” receptors in our brains to make us feel better. Yet another possible hormonal pathway starts with the increase in insulin from increased blood glucose levels, which increases the levels of tryptophan in the brain, which in turn increases the production of serotonin. Yet others still argue for a more complex pathway involving hormones, conditioning and timing. For example, as suggested by Judith Wurtman, although carbohydrates may reduce stress, they can only do so when stress is present. Given that we typically feel more stressed as the day progresses, a carbohydrate-rich meal will have a greater stress-reducing impact if eaten later in the day than earlier.

In sum, there does appear to be something behind the name comfort food. Whatever the mechanism, eating high-calorie, high-carbohydrate and/or high-fat foods produces a pleasant, stress-reducing and pain-alleviating feeling in the eater. Although there is, in a sense, nothing wrong or problematic with eating this food to produce this effect, repeated consumption of these foods is not without its side effects. Moreover, the dangerous combination of increased accessibility, both in terms of ease of access to these foods and their low cost, and increased stress makes the appeal of these foods that much stronger. Making these foods so familiar and ubiquitous may only compound the problem. Indeed, some research along the lines of terror-management theory suggests that thoughts about one’s own mortality lead to a preference for familiar, local high-calorie chocolates and soft drinks.

The challenge now is to find other, more healthy ways of reducing stress, even in these difficult economic times. We shouldn’t get rid of the ice cream or slow-cooked ribs or burger and fries combo entirely, but rather be more selective in how and when we eat them, especially as a way of improving our mood.

For more see:

“Food and mood”, by Sara Abdulla, Nature News

“Comfort food and you”, by David Lin, The Science Creative Quarterly

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