Chocolate & Health - World Agroforestry Centre

24 Pages·2000·3.01 MB·English

Chocolate
Health
DEVELOPED BY THE
CHOCOLATE MANUFACTURERS ASSOCIATION
WITH TECHNICAL ASSISTANCE FROM
THE AMERICAN DIETETIC ASSOCIATION

Chocolate
PG.1 Health
The public loves chocolate. A survey of 1,000 American
adults found chocolate was ranked as their favorite flavor
for desserts and sweet snacks by a three-to-one margin.1
If asked, some consumers might admit to feeling somewhat
guilty about their enjoyment of chocolate although there is
no scientific basis for their guilt if chocolate is eaten in
moderation as part of a balanced eating plan.
Health professionals have a responsibility to provide
consumers with scientifically supported facts to help them
make informed dietary decisions.2 Despite research
to the contrary, chocolate consumption is sometimes
associated with deleterious effects on health. Such erroneous
beliefs typically are based more on popular folklore than
on facts.3 This booklet reviews the scientific literature
regarding chocolate and health to help place in perspective
the nutritional and medical aspects of this popular food.
By communicating current factual information about
chocolate, health professionals can help consumers
understand how chocolate can be part of a healthy eating
plan based on balance, variety and moderation.
This scientific overview addresses the following health
issues as they are associated with chocolate.
Chocolate
PG.2 Health
Acne:
PAGE There is no evidence that food,including
chocolate,has a direct role in the pathogenesis of acne.
Allergies:
PAGE Chocolate is not a common food allergen.
Antioxidants:
PAGE Chocolate is a rich source
of polyphenol antioxidants that may help guard
against cancer and heart disease.
Behavior:
PAGE Neither chocolate nor sugar cause
attention-deficit hyperactive disorder in children.
Caffeine:
PAGE Chocolate is not a major
contributor of caffeine to the American diet.
Cravings:
PAGE Women who crave chocolate likely
do so because of its flavor and mouth feel,not
because there are “addictive”substances in chocolate.
Dental Caries:
PAGE Neither cocoa nor unsweetened
chocolate are intrinsically cariogenic.While any food that
contains sugar or starch can cause dental caries,studies show
chocolate may be actually less cariogenic than many foods.
Diabetes:
PAGE The goals of the American Diabetes
Association's nutrition recommendations for people
with diabetes mellitus allow for consumption of sweets
such as chocolate as part of an appropriate eating plan.
Migraines:
PAGE Evidence suggests chocolate
is not a trigger for migraine headaches.
Obesity:
PAGE There is no evidence obese people consume
more chocolate than normal-weight people.
Serum Cholesterol:
PAGE Stearic acid is a major
saturated fatty acid in cocoa butter,the naturally
occurring fat in cocoa.Studies show that stearic
acid does not raise blood cholesterol.
Chocolate
PG.3 Health
Acne
B
asic research on the causes of acne
vulgaris links its occurrence to rising
testosterone levels during puberty.This
results in enlargement of the sebaceous
glands,which can eventually lead to the
development of comedones (blackheads).
The American Academy of Dermatology
has stated acne is not a dietary disease and large amounts of chocolate have not
following the strictest diet will not by itself clinically exacerbated acne.”9The paucity
clear the skin.4 of recent research on chocolate and acne
Yet the idea that diet,and specifically reflects the widespread acceptance of
chocolate,is implicated in the etiology of earlier studies acquitting chocolate of any
acne remained widespread within the contributing role in acne.
medical profession until recently.Among
the first to question the link between
chocolate and acne were researchers from Allergies
the University of Missouri in the 1960s.
Grant and Anderson5failed in their
A
attempt to induce an acne flare-up in eight food allergy is a reaction by the body’s
individuals with mild to moderate acne by immune system to a substance or ingredi-
feeding them a large amount of chocolate. ent in food – usually a protein.According
The authors discredited the assertion that to the National Institutes ofHealth,approxi-
chocolate causes acne. mately five million Americans (5-8 percent
A larger study of 65 subjects reported of children and 1-2 percent of adults) have
excessive intake of chocolate and fat did a true food allergy.Eight major food
not alter the composition or output of allergens account for 90 percentof all
sebum from subaceous glands or affect the allergic reactions:milk,eggs,peanuts,tree
course of acne.Upon review of studies nuts (such as walnuts or almonds),soy,
purporting to show that high carbohydrate wheat,fish and shellfish.Children are
or high fat diets aggravate acne,the authors most commonly affected by reactions to
concluded such claims are unproved and milk and eggs.Chocolate is an uncommon
that the sebaceous gland has a high degree food allergen.10
of autonomy.6In two articles,Shalita7/8 Some people,health professionals
has stated there is no evidence that food, included,incorrectly confuse the terms
including chocolate,has a direct role in the "food sensitivity" and "food allergy."11
pathogenesis of acne. A food intolerance or sensitivity is a
In an extensive review of research on reproducible adverse reaction,not
chocolate and acne conducted in 1978, psychologically based,which includes
Fries3concluded that the general trend of enzyme deficiencies,pharmacological
published reports suggested that chocolate effects,non-immunologic histamine-
ingestion was unrelated to the cause of releasing effects and direct irritation.A
acne.As cited in the Journal ofthe American food allergy or hypersensitivity is a form of
Medical Association: "Diet plays no role in food intolerance that includes an abnormal
acne treatment in most patients...even immunologic reaction mediated by
antibody and/or T lymphocytes.12/13
Chocolate
PG.4 Health
The only completely objective test for antigen testing include a large number
confirming a food allergy is the double- of clinically insignificant positive tests,
blind placebo-controlled food challenge cross-reactivity among foods from
(DBPCFC).14/15/16The most prevalent food common genetic families,and use of an
allergens confirmed by DBPCFC are eggs, improper antigen (i.e.,cocoa bean instead
milk,soy,fish,peanuts,tree nuts,and of processed cocoa).The cocoa bean goes
wheat.15 through several procedures (e.g.,fermenta-
Patients' perceptions and physicians' tion,roasting,grinding,conching) before
diagnoses of food intolerance are not it can be consumed as chocolate.26Thus,
always accurate;fewer than half of patients a higher incidence of positive cutaneous
with histories of adverse reactions to food tests may result than the incidence of
can be confirmed by means of objective clinical reactions to other ingredients or
testing.11In the case of chocolate,Fries17 the products of its digestion.3
was rarely able to confirm a parent's Chocolate candies may contain other
suspicions of a child's allergies. ingredients that can elicit allergic reactions,
According to Fries,3few scientific including such common foods as milk,soy
publications relate chocolate to allergy. lecithin,gluten,peanuts and tree nuts.This
Fries18reported positive skin test response highlights the importance of label reading
to the cocoa bean in about two-thirds of by people who may be sensitive to these
allergy patients.However,test results were ingredients.
not related to clinical symptoms. The diagnosis of chocolate reactions
Maslansky and Wein19questioned 500 should be based on reliable studies,
allergy patients regarding their tolerance of including food elimination and food
chocolate.Although 81 said they suffered challenge tests.27
from chocolate allergy,only 10 had the
requisite reproducible symptoms for inclu-
sion in the double-blind study.Eight of Antioxidants
these patients were challenged and only
three had a reaction.Of these three,only
C
one had both symptoms and a positive ocoa powder and chocolate are rich
skin test. sources of high quality polyphenol
In another study,20 patients with a antioxidants,28/29/30potentially beneficial
history of "allergic" reactions to chocolate compounds similar to those found in
were fed either placebo or cocoa in a fruits,vegetables and red wine that may
double-blind manner.The cocoa ingested have the potential to reduce the risk of
approximated the amount in an average developing heart disease and certain
size chocolate bar.Participants also were cancers.Cocoa polyphenols were
fed a chocolate bar at another point in the previously thought to only play a role
study.The authors concluded that only in flavor and aroma development in
one participant probably was allergic to chocolate,but more recently have been
chocolate.20Likewise,other studies21/22/23/24/25 studied for their antioxidant potential
rarely confirmed suspected reactions to and possible health benefits to humans.
chocolate by oral challenge. Science has long held that damage done
Dermal antigen tests to determine in the body by free oxygen radicals is
allergic response to foods can sometimes linked to heart disease,certain cancers and
be misleading.Problems with dermal physical degeneration maladies associated
Chocolate
PG.5 Health
TOP ANTIOXIDANT FOODS
ORAC* Units per 100 grams
*ORAC 13,120 DARK CHOCOLATE 980 BRUSSELS SPROUTS
(Oxygen Radical Absorbance Capacity)
6,740 MILK CHOCOLATE 949 PLUMS
is a measure of the ability of foods
to subdue harmful oxygen free radicals 5,770 PRUNES 930 ALFALFA SPROUTS
that can damage our bodies.
2,830 RAISINS 890 BROCCOLI FLORETS
2,400 BLUEBERRIES 750 ORANGES
2,036 BLACKBERRIES 739 GRAPES, RED
1,770 KALE 710 RED BELL PEPPER
1,540 STRAWBERRIES 670 CHERRIES
1,260 SPINACH 450 ONION
1,220 RASPBERRIES 400 CORN
390 EGGFPLANT
Source: Data from U.S. Department of Agriculture and the Journal of the American Chemical Society.
with the aging process.Antioxidants in the measurement methodology found dark
blood stream can help eliminate free chocolate to contain 13,120 ORAC units
radicals,potentially reducing the risk of per 100 grams,or more than twice the
developing some serious diseases. ORAC activity level of prunes (5,770
Among products derived from cocoa ORAC units per 100 grams) which
beans,cocoa powder contains the highest contains one of the highest levels of fruits
amount of polyphenols,followed by dark and vegetables tested.32/33
chocolate and milk chocolate.Depending Research focusing on the potential
upon the measurement methodology used, health benefits of polyphenols in cocoa
a 40 g (1.5 ounce) milk chocolate bar and chocolate has proven that they are
contains between 205-300mg of absorbed in the bloodstream.In a clinical
polyphenols,which compares favorably trial,eight subjects refrained from con-
to a five-ounce glass of red wine which suming foods rich in polyphenols from the
contains 210mg of polyphenols and has day before the test until the study was
been associated with reducing the risk of completed.Each subject consumed choco-
developing heart disease.28/29In a Dutch late with bread and water on two separate
study,chocolate was found to be a rich occasions:first consuming 40g of choco-
source of the polyphenol flavonoid late,and one week later,consuming 80g of
catechin,containing four times the chocolate.The total polyphenol intake
amount found in tea.31 from chocolate was 892mg,and 1783mg
By all forms of measurement reviewed, respectively.Blood samples were drawn
cocoa and dark and milk chocolate have before chocolate consumption and at inter-
high polyphenol antioxidant values vals of one,two,three and four hours after
compared to fruits and vegetables.A consumption.Blood analysis found levels
1999 analysis of chocolate’s polyphenol of the polyphenol epicatechin rose after
antioxidant levels utilizing the ORAC consumption of each chocolate sample,
(Oxygen Radical Absorbance Capacity) reflecting rapid absorption.34Other studies
Chocolate
PG.6 Health
have focused on the beneficial effects of the the effects of various foods,including
absorbed polyphenols.One study found chocolate,but none have focused solely
that feeding a diet of 1 percent cocoa on chocolate.However,the relationship
polyphenols to rabbits retarded low density between ADHD and ingestion of sugar,a
lipoprotein (LDL) cholesterol oxidation major ingredient in sweetened chocolate,
in their blood,potentially preventing a first has been explored in depth.The Food and
step in the formation of atherosclerotic Drug Administration (FDA)39concluded
plaque.35Feeding 35g of cocoa powder there is no substantive evidence that the
to 12 male subjects demonstrated a consumption of sugar is responsible for
significant increase in LDL cholesterol’s behavior change in children or adults.
resistance to oxidation within two hours Another review of 11 double blind
of cocoa consumption.36 studies conducted between 1984 and 1991
Ongoing human research continues to of sugar and ADHD in both "sugar
explore the health benefits of chocolate’s responders" and "non-sugar responders"
polyphenol content.Preliminary results of showed similar findings.38Nine of the
a Pennsylvania State University study that studies reported no significant effect of
fed controlled diets to 23 male and female sucrose on behavior.40/41/42/43/44/45/46/47/48One
subjects supports the potential protective study found decreased activity following
effects of polyphenol antioxidants in sucrose challenge49and one,the results
chocolate and cocoa.Subjects consumed of which were never replicated,noted
cocoa powder (22g) and dark chocolate inappropriate behavior after sucrose
(16g) in their daily diets.Blood analysis consumption.50The Surgeon General's
revealed that the subjects consuming the Report on Nutrition and Health2noted
cocoa and chocolate had improved limited data to support the idea that sugar
cholesterol ratios,with a higher ratio of causes uncontrolled behavior in children.
high density lipoproteins (HDL) to LDL. A 1994 study has contributed additional
A higher ratio of HDL to LDL is associated evidence that sugar does not affect a child's
with a lower risk for heart disease.The behavior.51In the double-blind trial,25
cocoa and chocolate also appeared to have preschoolers and 23 children aged six to 10
a beneficial effect on the oxidation of LDL years with a subjective history of sugar-
cholesterol.37 induced behavior changes were fed each of
three diets over a nine-week period.One
diet contained sugar at twice the amount
Behavior normally consumed by children,the
second contained aspartame,and the third
contained saccharin.All three diets were
A
n extensive literature search did not free of preservatives,food coloring,
reveal any studies in which attention- chocolate and caffeine.Tests on activity
deficit hyperactivity disorder (ADHD) level,concentration and memory showed
was observed as a direct response to no effect from any of the sweeteners.The
chocolate.38Past studies have observed American Dietetic Association has taken
the position that the use of nutritive and
nonnutritive sweeteners is appropriate
when consumed in moderation and within
the context of a diet consistent with the
U.S.Dietary Guidelines for Americans.52
Chocolate
PG.7 Health
Caffeine not proven this theory.Other foods
contain higher levels of the same bioactive
substances and are not associated with
A
lthough considerable research has been affecting mood.Phenylethylamine,for
conducted on the effects of caffeine on example,is a neurotransmitter-type
behavior in children,2the role of caffeine in substance similar to other substances that
chocolate is largely a non-issue.According improve mood when administered to
to the Institute of Food Technologists,53 certain depressed patients.The amount of
chocolate contributes only 1.5 percent of phenylethylamine in chocolate,however,is
children's total caffeine intake.Levels of quite small.Salami sausage contains about
caffeine range from 3 to 10mg in a typical nine times the amount of phenylethy-
1.4 ounce bar of milk chocolate,and from lamine found in chocolate and cheddar
2 to 7mg in an 8-ounce glass of chocolate cheese contains more than 10 times the
milk.An ounce of bittersweet chocolate level in chocolate,but neither food is
contains 5 to 35mg of caffeine and an generally associated with mood changes.58/59
ounce of unsweetened baking chocolate has Food cravings also have been associated
35 mg of caffeine – all considerably less with chocolate.Research on food cravings
than the approximately 75mg of caffeine indicate that chocolate is the most craved
found in an eight-ounce cup of instant food among women while men crave spicy
coffee or 135mg in the same amount of foods,such as pizza.60/61/62There may be
brewed coffee.54People differ greatly in several causes for food cravings,including
their sensitivity to caffeine,and stimulant restrictive diets that eliminate or signifi-
effects in adults may result from consump- cantly reduce consumption of certain
tion of 150 to 200mg.53 foods.This,in turn,may result in cravings
for those foods.63It also has been suggested
that food cravings may be the result of the
Cravings body’s need for certain nutrients,such as
the magnesium in chocolate or the calcium
in cheese.Scientific studies,however,have
F
ood cravings and the effect of diet on not confirmed this hypothesis.64/65
mood have been topics of many studies Research conducted by Michener and
over the past three decades.While research Rozin studied subjects who reported
has determined food cravings do exist, experiencing chocolate cravings at least
there is little scientific support for a link once a week.66Their methodology focused
between the consumption of certain foods on determining which of the two main
and behavior or mood changes. components of chocolate—cocoa solids
It has been hypothesized that carbohy- (powder) or cocoa butter—actually
drate consumption in general may improve satisfied cravings.Cocoa powder contains
mood by increasing tryptophan transport all of the bioactive ingredients found
to the brain,resulting in increased sero- in chocolate,whereas “white chocolate”
tonin levels.55Studies in this area,however, is made from cocoa butter,milk and
have produced inconsistent results.56/57It has flavorings but contains none of the
been suggested that chocolate may elevate bioactive ingredients.
mood,due to certain bioactive compounds When the subjects experienced
it contains,such as tyramine and chocolate cravings,they were given one
phenylethylamine.58/59Science,however,has of the following:milk chocolate,white
chocolate,cocoa powder in a capsule,
Chocolate
PG.8 Health
white chocolate along with a capsule Dental Caries
of cocoa powder,a placebo capsule or
nothing at all.
T
If chocolate cravings were related to ooth decay begins when bacteria,
chocolate’s bioactive ingredients,then particularly Streptococcus mutans,accumu-
the cocoa powder capsule and the milk late on the teeth in the absence of adequate
chocolate sample should have satisfied the oral hygiene,forming plaque.Bacteria
cravings.However,this was not the case. metabolize fermentable carbohydrates,
Only the milk chocolate,and to a lesser leading to acid formation and a decrease in
extent,the white chocolate (which contains plaque pH.Frequent or sustained drops in
no bioactive ingredients) satisfied the pH can result in progressive demineraliza-
cravings.The cocoa powder capsules had tion of the enamel,ultimately leading to
a similar effect to consuming nothing. caries.The etiology of caries is a combina-
The study concluded that the sensory tion of elements:susceptible teeth,dental
experience of eating chocolate,not the plaque,food and the length of time food
bioactive components,were the important remains in contact with the teeth.69
factor in satisfying the craving for Prevention of dental caries,therefore,
chocolate.66 requires several measures.It is well known
The menstrual cycle also appears to that fluoride is a primary factor in the
influence dietary intake and food cravings. control of dental caries and can signifi-
There is some scientific evidence that cantly reduce caries.69Other intervention
women crave sweet foods in the methods include control of fermentable
pre-menstrual and menstrual cycle while carbohydrate intake,proper oral hygiene
fiber intake decreases.65There is,however, and the application of plastic sealants.2
also an increase in overall appetite in the There may even be a hereditary disposition
pre-menstrual period.67/68Claims that to caries resistance.70
women with PMS or depression consume While sugars have been implicated in
carbohydrate and chocolate to self- the development of dental caries,39it has
medicate have little scientific support. long been known that any food containing
Again,it appears that increased consump- fermentable carbohydrates—including
tion of these foods is linked to their flavor cooked starches such as bread,cereal,
and other sensory properties rather than crackers,etc.—can promote caries
the bioactive compounds they contain. formation.71/72The cariogenicity of food is
related to the amount of total fermentable
carbohydrates.It is often assumed that
starchy foods such as potato chips and
bread are not a factor in caries develop-
ment because oral bacteria cannot break
down starches into acids.However,most
starchy foods are retained in the mouth
long enough to mix with saliva,which
contains the enzyme "amylase" that
converts starches into sugars,which the
oral bacteria then can metabolize to acids.73
In fact,sugars such as sucrose and fructose
tend to be less cariogenic than starch
because they dissolve in water and saliva,