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Biology 103
2001 Second Web Report
On Serendip


by M. Bond

What is it about chocolate? I found myself pondering this question one evening as a dinning services employee in charge of filling the chocolate mouse and chocolate pudding trays. Unlike the yogurt, fruits, marble cake, and apple sauce the chocolate items were the first to disappear. Perhaps the chocolate desserts were so popular because of biological reasons. Bryn Mawr is a women's college and there are various myths about how chocolate is more appealing to women than men. In addition to gender related myths chocolate is believed to have some affect on mood in humans. While many of the myths about chocolate are clearly fictional there is varying scientific research that suggests chocolate contains chemicals that effect mood and health.

Chocolate comes from cocoa beans and contains about 300 chemicals (1)(2). The cocoa bean comes from the Cocoa Tree, which is native to Central America and South America. The beans are dried and then exported. Once the beans reach manufacturers they are processed and eventually made into the product known as coco. This is then used to make chocolate. The finished product is believes to have various side effects when consumed. Phenyl ethylamine (4) is one of the hormones present in chocolate. This hormone is similar to an amphetamine (3). It makes the neurotransmitters in the brain move more quickly (1). This helps a person who has consumed chocolate stay alert. This hormone is the same one that is known to produce the "runner's high" in long distance runners. It gives an energetic boost. Caffeine and Theo bromine produce a lifting of the spirits as well. Chocolate is known to contain some caffeine but not nearly as much as coffee or tea. One cup if cocoa contains only 0-25mg of caffeine, while the same amount of coffee contains 50-175mg of caffeine (5). In such a small concentration the caffeine in chocolate does not have the impact of other caffeinated foods, which are known to increase energy for a short period of time and than cause fatigue. However the little bit of caffeine in chocolate combines with the Theo bromine to produce a boost (1). Theo bromine, like caffeine, is a stimulant. The caffeine and Theo bromine in chocolate exist in small dosages but scientists believe when combined they have an impact on the person eating the food. This boost caused by chocolate is the reason why chocolate is harmful to some animals. For example the nervous and cardiovascular systems of dogs can not handle the stimulation chocolate causes (2). In addition to these chemicals chocolate induces cannabinoid and seratonin production in the brain. Both of these chemicals are related to happiness.

The chemicals found in chocolate are not limited to making humans happy. Recent studies suggest that certain forms of chocolate have health benefits. It has long been assumed that eating chocolate is a guilty pleasure because the food has no nutritional value. It is fairly high in sugar and fat. Despite these beliefs, chocolate has some fats that are good for the body. According to a Hershey study some milk chocolate products contain conjugated lion oleic acid also known as CLA (6). This trans fat is believed to fight cancer in animals. The only problem with this study is that the amount of CLA found in milk chocolate was so small that a person would have to eat about 10 pounds of chocolate a day to benefit from the trans fat. Another study by Nestle Research Center found that a change in dark chocolate might help lower cholesterol. The study tested dark chocolate that used calcium carbonate in the place of some sugar. The taste was unchanged in the new chocolate. Results showed that ten men feed the altered chocolate experienced a drop of 15% in their low-density-lipoprotein (LDL) cholesterol levels. The reason for this drop is that with the altered chocolate the subjects excreted much of the extra fat plus the amount of sugar in the chocolate was decreased. Despite these findings the chocolate manufacturers have yet to release the new brand of chocolate. Another study at University of California, Davis found evidence of phenolics in chocolate. Phenolics are the same chemical found in red wine that helps lower the risk of heart disease. It reduces the oxidation of LDL preventing it from creating plaque in the arteries (1). This study is particularly encouraging because heart disease has become a major cause of death in the United States of America. This is not to say that drinking red wine or eating chocolate will solve the problem but as we learn more about pheonolics we will hopefully find more ways to combat the desease.

All of the studies that have given insight into the connection between chocolate, mood, and health have not explained the reasons for the addictive quality of chocolate. Many self-labeled chocoholics claim that chocolate is like a drug. A study at Pennsylvania University found that many of the people who claim to be addicted to chocolate are actually addicted to its "melt-in-your-mouth" texture rather than the chocolate (3). Another study by the University of Arizona showed that texture, smell, and aroma are related to chocolate addictions but there are other reasons for people loving the sweet so much. Cravings for the treat were often episodic and fluctuated with hormonal change in this study (2).. This led the researches to believe that chocolate cravings are related to gender. The myth that women crave chocolate because of hormonal changes during the menstrual cycle is supported by this study.

Many believe that chocolate has different effects on men and women. This belief is based on cultural myths. Deborah A. Zellner led a study at Shippensburg University that suggests chocolate cravings are unrelated to sex (3). The study included men and women from Shippensburg University in the United States of America and from University Nacional de Educacion a Distancia in Spain. The men and women reported cravings of different foods over a period of time. The Americans reported that 24.6% of the women craved chocolate most often while only 17.4% craved chocolate most often (3). The Spanish women reported that 28.6% craved chocolate most often and 22.2% of the men craved chocolate most often. The two experiments had very different results suggesting that the argument that women crave chocolate more than men may be a cultural difference rather than scientifically based concept.

Studies on chocolate are varied and each one gives a different reason for the popularity of the food. One conclusion is that this food holds benefits for humans in several different ways. Health wise chocolate has components that help fight heart disease. It also has the ability to make people happier and gives a boost of energy. All of the studies prove that chocolate is unlike any other sweet. The reasons for these differences are not yet completely understood. However with each study we come closer to understanding the science of chocolate. For now the benefits of eating chocolate outweigh any negative effects of the food.


WWW Sources

1) Exploratorium Site

2) ?

3) The Science of Chocolate

4) ?

5) ?

6) Chocolate - Science News



Anonymous's picture

Theo-bromine/chocolate and Eton's Alex

The theo-bromine in chocolate is known to break the contact between mucus and pulmonary membraneous tissue.

I wondered whether it was, or could-be, a usefull component of the medication given to Eton's Alex.

He is worthy of every effort pssible to improve his health and life-span!