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Chocolate: Cure or Comfort?

 

Mallory Mitchell

September 24, 2007

 

 

“Chocolate causes certain endocrine glands to secrete hormones that affect your feelings and behavior by making you happy. Therefore, it counteracts depression, in turn reducing the stress of depression. Your stress-free life helps you maintain a youthful disposition, both physically and mentally. So, eat lots of chocolate!” Elaine Sherman, Book of Divine Indulgences

 

 

Introduction

The delectable delicacy that we now know today as chocolate was the seed of the tropical cacao tree. This particular tree is native to South America; however, the cacao tree has been cultivated in both Central America and Mexico for hundreds of years now. Its earliest known use was actually around 1100 BC (http://en.wikipedia.org/wiki/Chocolate).

When we think of chocolate in modern civilization, we think of a sweet, high calorie treat or dessert ingredient. Many find it absurd that some dare to make claims that something as presumably unhealthy as chocolate could ever have any type of medicinal purpose. Yet, surprisingly, up until as recently as the 19th century, chocolate was most commonly used as medicine in various countries and cultures worldwide. Indigenous people have historically used the fruits of the cacao tree to treat depression, fatigue, weight gain, and even poor sex drive (http://www.womenslife.co.za/Default.asp?action=article&ContentTypeID=2&SubContentTypeID=5&ContentID=1608).

This being said, is the idea of chocolate treatment as outlandish as some people may think?  Why exactly is it that we hastily reach for the chocolate bar when we are feeling blue? Moreover, if chocolate itself is not what is delivering us feelings of euphoria, what mechanisms actually are at play? In the following sections, the answers to these and other similar questions will be answered as we further examine the possibility of chocolate as an antidepressant.

 

 

 

What about chocolate potentially makes us happy?

            The actual science of chocolate has been a topic of particular interest for quite some time.  Scientists have varying theories regarding chocolate’s chemical composition that provide possible explanations for why it could possibly induce legitimate adverse effects for negative moods.

Chocolate contains a variety of substances, some of which have an effect on body chemistry. These include:

(http://en.wikipedia.org/wiki/Chocolate)

Pharmacologically active ingredients of chocolate

Compound

Amount
(%W/W)

Neurotransmitters:

 

Serotonin

0.62 - 5.82

Histamine

0.04 - 0.13

Methylxanthines:

 

Theobromine

<1.3

Caffeine

ND

Tetrahydroisoquinolines:

 

Salsolinol

High

Methyltetrahydroisoquinoline

<0.01

Amines:

 

Phenylethylamine

0.02 - 2.20

Tele-methylhistamine

0.01 - 1.54

Spermidine

0.05 - 1.15

p-tyramine

0.02 - 0.35

3-methyloxytyramine

0.02 - 0.33

Tryptamine

0.03 - 0.18

Spermine

0.00 - 0.13

ND = not detected

Source: Biochemist, Apr/May 1993, p 15.

 

            Some theorize that chocolate contains antidepressant amino acids such as tryptophan, phenylalanine and tyrosine.  In particular, tryptophan is known to increase the body’s uptake of serotonin which serves as a natural antidepressant, meaning “a natural non-prescription way of combating depression, reducing stress, or just raising mood, spirits and sense of well being….”http://www.womenslife.co.za/Default.asp?action=article&ContentTypeID=2&SubContentTypeID=5&ContentID=1608).

 

            It is estimated that chocolate contains approximately 300 known chemicals. Included in these chemicals are the stimulants caffeine and theobromine. Although a neglible amount of caffeine (it would take 800g of milk chocolate to match the equivalent of caffeine in one cup of coffee) are present, theobromine exists in sizeable amounts. This chemical is known to have relatively weak stimulant effects, but some scientists believe that, in combination with the other chemicals present, the effects are potentially noteworthy.

Unfortunately, “other substances in chocolate that have been discussed as pharmacologically significant include histamine, serotonin, tryptophan, phenylethylamine, tyramine, salsolinol and magnesium. But many of these exist in higher concentrations in other foods with less appeal than chocolate.” (http://www.chemsoc.org/chembytes/ezine/1997/chockie.htm)

 

 

The Expert Opinion

            In a widely known 2005 study, Gordon Parker, of the University of New South Wales, Australia, examines “why people crave and eat chocolate, particularly in the context of food cravings and emotional eating, and chocolate's mood state effects.” This study is accomplished through a review of chocolate’s chemical properties and also through a thorough examination of chocolate’s alleged mood altering powers. It addresses the suspected effects of many of the aforementioned chemicals present in chocolate such as caffeine, theobromine, phenylalanine, and tyramine.  However, this study highlights the fact that each of the chemicals are present in insignificant amounts in chocolate. The same chemicals exist in large amounts in other foods, yet these foods provide no sense of euphoria.  Thus, it must not actually be the chemicals at play. It concludes that,”for most people chocolate invokes anticipatory and consummatory pleasure, and is therefore an indulgence. When taken in response to a dysphoric state as an ‘emotional eating’ strategy it may provide some transient ‘comforting’ role but it is more likely to prolong rather than abort the dysphoric mood. It is not, as some would claim, an antidepressant, (Parker, 2006).”

In an alternate experiment conducted by Hendrik J. Smit of the University of Bristol, the focus was placed more on the presence of pharmacologically active compounds in chocolate and whether or not they produce significant psycho-activity.  The experiment was conducted by means of two double blind, placebo-controlled studies that intended to measure the effects of cocoa powder and methylxanthines found in a 50g chocolate bar.  In the first study, the participants were treated with 11.6 g of cocoa powder and a combination of caffeine and theobromine. They were a give a test battery once before and twice after their treatments. The second study consisted of a simple reaction time task, a rapid visual information processing task, along with a mood questionnaire that aimed to investigate the effects of both “milk” and “dark” chocolate. Their particular experiment confirmed that a normal portion of chocolate will facilitate some psychopharmalogical activity, largely as the result of caffeine and theobromine combination.

A third and more recent study, conducted in Germany in 2007 by Michael Macht and Jochen Mueller, examined the effects of chocolate on negative, positive, and neutral moods and also whether or not these outcomes were simply due to palatability.  In this experiment, moods were induced in participants through the use of film clips. Results showed that eating chocolate reduced mood greater in comparison to the mood reduction that occurred in participants who were given water instead. 

Characteristics of participants in experiment 1

 

Water

Chocolate

Women

14

13

Men

10

11

Age (year)

26.0±7.9

24.5±5.9

BMI

21.4±1.7

21.2±2.2

Eating habits (DEBQ)

 Dietary restraint

2.3±0.5

2.6±1.0

 Emotional eating

2.4±0.6

2.6±0.8

 External eating

3.3±0.6

3.5±0.5

Personality (NEO-FFI)

 Neuroticism

1.9±0.6

2.0±0.7

 Extraversion

2.4±0.6

2.5±0.6

 Openness

2.8±0.4

2.8±0.4

 Agreeableness

2.7±0.4

2.6±0.5

 Conscientiousness

2.7±0.6

2.7±0.6

Data are means±SD.

The second part of the experiment showed that mood was reduced by eating palatable chocolate as opposed to non-palatable chocolate or nothing at all.  The conclusion reached was that experimentally induced moods could be reduced by the intake of chocolate. However, these effects were simply due to palatability and were therefore, highly ephemeral.

 

 

Conclu

 

Psychology Department

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sion

Maybe there are some chemical factors at play that make chocolate so pleasurable. However, that chocolate high tends to come crashing down within minutes, failing to sustain the euphoric state that it induces. Therefore, it can be concluded that not enough substantial evidence or studies exist at this time to classify chocolate as a noteworthy antidepressant.

 

References

 

Macht, M., Mueller, J. (2007). Immediate effects of chocolate on experimentally induced mood states. Retrieved September 22, 2007

 

Parker, G., Parker, I., Brotchie, H. (2006). Mood state effects of chocolate. Journal of Affective Disorders, 92,( 2-3), 149-159., from Science Direct database.

 

Smit, H., Gaffan, E., Rogers, P. (2004). Methylxanthines are the psycho-pharmacologically active constituents of chocolate. Pharmacology, 176(3-4

), 412-419.