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A Tablespoon of Sugar Makes the Stress go Down

The Science Behind the Sweetooth

“I need a cookie or a candy bar. Do you have a vending machine here?” The woman was standing next to me at the service counter while a mechanic was explaining to her the cost to repair something essential in her car. Moreover, she was going to have to leave her car for two days because the part was not in the shop. The mechanic wanted to know if they should call a taxi for her. I mentioned to her that I saw a vending machine in the waiting area, and, as I was going there to wait for my car’s state inspection results, I escorted her to the vending area whereupon she immediately bought a candy bar.

“I never eat sweets,” she told me. “I know they are like poison to my body. But I am so upset, I have to eat something. Otherwise I may just scream with frustration!” The service man came over and told her a taxi would be there soon. “Okay,” she answered. “I’ll just sit here and eat my Snickers bar.“ She was already tearing off the wrapper with her teeth.

I laughed to myself as I went to collect my car, remembering the many times when a brownie, cookie or doughnut prevented me from sinking into some emotional puddle. The stress relief might take a few minutes, but no more than the time it took for a pain reliever to relieve a headache pain and, unlike a pill, the stress reliever always tasted wonderful.

Many of us reach for a sweet carbohydrate when we are upset and assume we feel better after eating because our taste buds are so happy. The sensory pleasure we get from a still gooey brownie or meltingly creamy piece of chocolate is undeniable. But the sensation on our tongue, or in the so-called pleasure centers in our brain, lasts for a very short time. The real effect on mood comes perhaps 10-15 minutes later, after the taste sensations are but a memory. The calmness that descends, the feeling that we will be able to manage, to cope, to figure out how to handle a difficult situation, gradually replaces the anxiety and worry we felt minutes before. The taste of the food is not doing this. If it were, it might be possible to unstress us by dropping a sweet solution onto the taste buds, i.e. after a few seconds stress would vanish. If something like that actually worked, you can be sure several companies would already be selling products known as "good mood" drops.

To achieve that sense of “comfort” from a sweet tooth must-have, you have to swallow and digest the sweet food in order to feel the relief you are seeking, if you want the comfort to last more than a few nanoseconds. Why? The answer is that after being digested, all carbohydrates, be they sweet, crunchy, salty, soft, hard, bland or amazingly delicious, will trigger a process in the body that ends up with the brain making new serotonin. In fact, the only carbohydrate that does not produce this effect is the carbohydrate fructose, which is found in fruit and used as a sweetener in many processed foods. Serotonin, the good mood brain chemical, takes the edge off anxiety, anger, depression, and frustration, as well as that feeling of being overwhelmed. Somehow serotonin provides a sense of an emotional mental breathing space so we can calmly (more or less) figure out how to cope. No food, no matter how delicious, is going to resolve the problem that made us seek it out, but at least it can help calm us down enough to start to figure how to begin thinking about a solution.

A recently published study in the Journal of Clinical Endocrinology Metabolism by Tyron, M., Stanhope, K., Epel, E. et al reported that the consumption of a sugary beverage relieved the stress their female volunteers were feeling when faced with difficult mathematical problems. (I can relate to this.) Women consumed a beverage containing sugar or the non-nutritive sweetener aspartame three times a day for two weeks. Those given the sugary drinks had a significantly lower level of stress-associated cortisol than women drinking the artificially sweetened beverage. The seemingly potent effect of sugar on decreasing stress is the reason, the authors conclude, people may be “hooked on sugar" and as a result, obese. One could ask, however, whether it is the sugar or the stress that is making us obese. The study did not answer that question.

Of course, you or their subjects do not have to eat sugar to feel better. Any non-fructose carbohydrate would have had the same effect. If they had eaten a bowl of rice or oatmeal three times a day their stress would also have lessened. So why do we really want something sweet when stressed? Maybe because sugar is digested faster than a high-fiber carbohydrate, so the comfort occurs sooner. Or maybe we seek out a pleasurable taste as a ‘reward’ for the emotional upheaval stress brings; but perhaps it is a combination of both.

Will eating sugar really make us obese if we seek it to feel better? That depends on whether we eat it alone, as sugar added to iced tea, for example, or eat it in a food that contains copious amounts of fat like a chocolate chip cookie. The amount of sugar needed to activate serotonin synthesis and reduce stress is about two tablespoons or about 25-30 grams. In calories, that’s about 100 to 120. Two MacDonald’s chocolate chip cookies contains 30 grams of sugar and 336 calories.

Stress is inevitable; eating may help us cope and manage our emotional responses, but no food will resolve the problems causing the stress. Fortunately, nature has given our brains the ability to calm us down when life dumps its stress on us. Drinking sugar-sweetened tea, or eating a bowl of oatmeal won’t fix an overflowing washing machine or change a dreaded medical diagnosis, but it will, at the very least, give us a respite from the stress these situations bring.


More from Judith J. Wurtman Ph.D.
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