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Chocolate Shown to Combat
Aging
Life by chocolate, or death by chocolate?
Feb 2004
There is an
increasing outflow of pro-chocolate PR, and much of the excitement centers
around antioxidants. Fruits and vegetables contain antioxidants, which have
the ability to temper free radicals, and thereby help to lower the risk of
heart disease, some cancers and other age-related maladies. More and more
people are trying to bombard their diets with the antioxidant fountain of
youth.
Enter chocolate, stage left. Chocolate, derived from the beans of the cacao
tree, is brimming with antioxidants, in much higher concentrations than
other produce. This could be because chocolate is highly concentrated,
undiluted by the water that makes fruits and vegetables so juicy.
How it works: the Biology
Big picture: Although we need oxygen to live, oxygen is dangerous. It's like
using dynamite to light a stove. Humans have evolved to breathe
oxygen-containing air, but it's a volatile substance. Not surprisingly,
plants have opted to avoid oxygen and to release it whenever possible. That
could be why trees can live so much longer; their bodies aren't constantly
bombarded with destructive oxygen.
According to a USDA article ("Vitamins and Minerals, Free Radicals and
Aging" by Jack Saari - link to article), the most popular explanation of
aging illness is the "oxidative theory," or "free radical theory." This
theory says that, though oxygen is necessary to human life, it is also
increasingly harmful as we age.
A natural byproduct of metabolism, oxygen can be transformed into free
radicals. Free radicals are atoms or molecules that have an unpaired
electron. They are usually very unstable, trying to bind with anything that
will give them their missing electron. (source). These free radicals wreak
havoc on protein, DNA and fat molecules, upon which our bodies depend.
The USDA article explains that to combat free radical damage, our bodies
have antioxidant enzymes. These enzymes weaken over time, however, and the
body's defenses can be boosted by the ingestion of antioxidant-containing
foods, or foods that contain vitamins that boost antioxidants in the body.
For example, vitamins C and E have been shown to act as antioxidants, which
means that they bind with the free radicals, thereby disarming their
destructive potential.
Antioxidant foods are rated by their ORAC, or "oxygen radical absorbance
capacity," which is a food's ability to calm free radicals. And this brings
us back to chocolate.
Dark chocolate, per 100 grams, has twice the ORAC of milk chocolate, four
times the ORAC of raisins and about ten times the ORAC of raspberries,
according to data (link to data) from the USDA and the Journal of the
American Chemical Society.
ORAC per 100 grams
13,120 Dark Chocolate
6,740 Milk Chocolate
5,770 Prunes
2,830 Raisins
2,400 Blueberries
1,770 Kale
980 Brussel Sprouts
739 Red Grapes
400 Corn
390 Eggplant
Dr. Ronald Prior, a USDA nutrition researcher, has studied the antioxidant
potential of chocolate.
"Dark chocolate is going to be on the high end, higher than most fruits and
vegetables," Prior said.
He stressed the importance of eating a variety of antioxidant-containing
foods, however. "It's the combination that's going to be beneficial," Prior
said.
Dark, Milk or White Chocolate?
Dark.
One recent study, "Plasma antioxidants from chocolate" (Nature, 8/03),
showed that eating plain, dark chocolate increased antioxidant capacity.
These gains, however, were significantly reduced if the chocolate was milk
chocolate or consumed with milk. The study concluded that milk may erase the
benefits of eating dark chocolate.
Another study, "Chocolate and Blood Pressure in Elderly Individuals with
Isolated Systolic Hypertension" (Journal of the American Medical
Association, 8/03), focused on white chocolate versus dark chocolate. The
study compared 13 men and women, ages 55-64, who had untreated, mild
hypertension.
Participants were randomly assigned 14 days of either 90 grams of white
chocolate or 90 grams of dark chocolate. Within 10 days of the 14-day
experiment, those eating dark chocolate had significantly lowered their
blood pressure, while those eating white chocolate had not benefited.
However, the results did not last beyond the chocolate intake; participants'
blood pressures returned to the pre-chocolate level within two days of
stopping chocolate intake.
Source: http://www.consumerhealthjournal.com/articles/chocolate.htm
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Sweet! Study says dark chocolate has
benefits
Flavonoids can lower blood pressure, researchers say
20 July 2005
WASHINGTON (Reuters) -- Dark chocolate can not only soothe your soul but can
lower blood pressure too, researchers reported Monday.
The study, published by the American Heart Association, joins a growing body
of research that show compounds found in chocolate called flavonoids can
help the blood vessels work more smoothly, perhaps reducing the risk of
heart disease.
"Previous studies suggest flavonoid-rich foods, including fruits,
vegetables, tea, red wine and chocolate, might offer cardiovascular
benefits, but this is one of the first clinical trials to look specifically
at dark chocolate's effect on lowering blood pressure among people with
hypertension," said Jeffrey Blumberg of Tufts University in Boston, who led
the study.
"This study is not about eating more chocolate," Blumberg added. "It
suggests that cocoa flavonoids appear to have benefits on vascular function
and glucose sensitivity."
Scientists are far from being able to make specific recommendations for
patients based on their research on chocolate, and nutritionists have urged
people to be cautious because chocolate is high in fat, sugar and calories.
Blumberg and colleagues at the University of L'Aquila in Italy studied 10
men and 10 women with high blood pressure.
For 15 days, half ate a daily 3.5 ounce (100 gram) bar of specially
formulated, flavonoid-rich dark chocolate, while the other half ate the same
amount of white chocolate.
Then each group "crossed over" and ate the other chocolate.
"White chocolate, which has no flavonoids, was the perfect control food
because it contains all the other ingredients and calories found in dark
chocolate," Blumberg said.
"It's important to note that the dark chocolate we used had a high level of
flavonoids, giving it a slightly bittersweet taste. Most Americans eat milk
chocolate, which has a low amount of these compounds."
Writing in the journal Hypertension, Blumberg's team said when the
volunteers ate the special dark chocolate, they had a 12 mm Hg decrease in
systolic blood pressure (the top number in a blood pressure reading) and a 9
mm Hg decrease in diastolic blood pressure (the bottom number) on average.
Blood pressure did not change when the volunteers ate white chocolate.
"This is not only a statistically significant effect, but it's also a
clinically meaningful decline," Blumberg said. "This is the kind of
reduction in blood pressure often found with other healthful dietary
interventions."
Eating dark chocolate also seemed to improve how the body used insulin, and
reduced low density lipoprotein (LDL) or "bad" cholesterol by about 10
percent on average.
"The findings do not suggest that people with high blood pressure should eat
lots of dark chocolate in lieu of other important blood pressure-reduction
methods, such as medication and exercise," Blumberg said. "Rather, we are
identifying specific flavonoids that can have a benefit on blood pressure
and insulin sensitivity."
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A Dark Chocolate a Day Keeps the Doctor
Away
Daily Dark Chocolate Good for the Heart, Loaded With Flavoniods
By Daniel DeNoon
WebMD Medical News Reviewed By Brunilda Nazario, MD
on Tuesday, June 01, 2004
Here's news that's hard not to like. Eating a small, 1.6-ounce bar of dark
chocolate every day is good for you. Very good for you, find Mary Engler,
PhD, RN, of the University of California, San Francisco, and colleagues.
Now here is a medical experiment you would love to volunteer for. Engler's
team divided 21 healthy adults into two groups. One group got a Dove Dark
Chocolate bar every day for two weeks. Like other dark chocolate bars with
high-cocoa content, this one is loaded with something called epicatechin.
Epicatechin is a particularly active member of a group of compounds called
plant flavoniods. Flavoniods keep cholesterol from gathering in blood
vessels, reduce the risk of blood clots, and slow down the immune responses
that lead to clogged arteries.
The second group that didn't get Dove bars wasn't totally left out. They,
too, got dark chocolate bars. But their treats had the flavoniods taken out.
All subjects underwent high-tech evaluation of how well the blood vessels
dilate and relax -- an indictor of healthy blood vessel function. Blood
vessel stiffness indicates diseased vessels and possible atherosclerosis.
Those who got the full-flavonoid chocolate did significantly better. Why?
Blood tests showed that high levels of epicatechin were coursing through
their arteries.
"This is the longest clinical trial to date to show improvement in blood
vessel function from consuming flavonoid-rich dark chocolate daily over an
extended period of time," Engler says in a news release. "It is likely that
the elevated blood levels of epicatechin triggered the release of active
substances that ... increase blood flow in the artery. Better blood flow is
good for your heart."
Why Dark Chocolate Is Different
Not all chocolate is created equal. Dark chocolate contains a lot more cocoa
than other forms of chocolate. And standard chocolate manufacturing destroys
up to half of the flavoniods. But chocolate companies have now learned to
make dark chocolate that keeps up to 95% of its flavoniods.
Sure, this seems like a scam. Can't you get more and better flavoniods from
other foods? Surprisingly, the answer is "not really." Engler says that dark
chocolate contains more flavoniods than any other food -- including green
tea, black tea, red wine, and blueberries.
"Many people don't realize that chocolate is plant-derived, as are the
fruits and vegetables recommended for a healthy heart," Engler says.
While a little dark chocolate is good, a lot is not better. Chocolate still
is loaded with calories. If you're going to eat more chocolate, you'll have
to cut back somewhere else. And remember that a balanced diet -- and plenty
of exercise -- is still the key to heart health.
Engler's study was funded by the University of California, San Francisco,
School of Nursing. The American Cocoa Research Institute, a nonprofit group
funded by the chocolate industry, provided the chocolate used in the study.
The findings appear in the June issue of the Journal of the American College
of Nutrition. Engler previously reported the findings at the 2002 Scientific
Sessions of the American Heart Association and at the Experimental Biology
2003 meeting.
SOURCES: Engler, M.B. Journal of the American College of Nutrition, June
2004; vol 23: pp 197-204. News release, University of California, San
Francisco.
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Chocolate for Life
Are you a chocoholic? Don't worry - that's a good thing.
Chocolate may be one of the most functional foods out there
By Willow Lawson
Feb 2003
Cliched as it is, maybe that box of Valentine's Day chocolates isn't such a
bad idea.
In recent years, studies have absolved chocolate of causing acne, cavities
and high cholesterol levels. But a new study goes even further, proving that
chocolate may be one of the most functional foods out there, even a great
brain saver. Of course, you don't need any persuading that it's probably the
most delicious as well.
Chocolate turns out to be a good source of antioxidants - those beloved
chemicals known for their cell-protecting properties. Antioxidants scavenge
and fight off free radicals, wildly reactive rogue molecules of oxygen that
damage cell membranes and the DNA, which contains the cells basic operating
instructions. Free radicals aid and abet heart disease by oxidizing the
"bad" (LDL) cholesterol, leading to hardened arteries. Free radicals are
also linked to cancer and degenerative diseases in all parts of the body.
The battle between antioxidants and free radicals takes place at the most
basic level in our bodies. Free radicals have an odd number of electrons,
which makes them unstable; they steal electrons wherever they can find them.
Antioxidants have the ability to donate an electron, neutralizing free
radicals without becoming free radicals themselves.
The brain is particularly susceptible to free radical damage because it is
exposed to a large amount of oxygen; as the body's most metabolically active
organ, it consumes about 20% of the body's oxygen, although it totals only
2% of our body weight. Free radicals enter our bodies through pollution,
fried food and even just normal metabolic processes of the body.
The fatty membranes that cover all brain cells are particularly subject to
oxidative damage. Free radical damage is implicated in cognitive decline and
memory loss as people age and in Alzheimer's disease.
A steady level of antioxidants - including vitamins C and E and beta
carotene - is linked to strong memories, according to studies in the
Netherlands and Australia.
The body gets antioxidants both by manufacturing them and consuming them in
foods. They are found most abundantly in fruits and vegetables, but all
plants have at least a small amount of antioxidants. Dietary sources of
these chemicals are particularly important during stressful times, when body
loses its ability to make them.
Berries, tea, garlic and wine are all well-known sources of antioxidants.
But cocoa beans top them all, says Joe Vinson, Ph.D., a chemistry professor
at the University of Scranton in Pennsylvania. His research shows that cocoa
beans are the most potent source of polyphenols, a large subgroup of
antioxidants. Scientists have identified around 6,000 antioxidants so far,
says Vinson. About 4,000 fall into the category of polyphenols.
Because polyphenols are found in the cocoa bean - not the milk, cream, sugar
or other additives - the darker the chocolate, the better. As a general
rule, antioxidants are found in the pigments of fruits and veggies, so the
more colorful the food, the richer in antioxidants.
By weight, cocoa powder packs the most antioxidant punch, according to
Vinson's research. "It is loaded!" the chemist says. It has twice as many
antioxidants as dark chocolate, which in turn has twice as many as milk
chocolate. White chocolate has no antioxidants at all.
The amount of polyphenols in a serving of dark chocolate is comparable to
that in a cup of black tea and higher than in a glass of red wine, things
long touted as great sources of antioxidants.
Hot chocolate is the best bet for those looking for the antioxidant punch
without the paunch that cocoa butter could bring. But it's important to make
the hot chocolate from scratch, with pure cocoa powder, milk and sugar, says
Vinson. His studies have shown that homemade hot chocolate has five times as
many antioxidants as a store-bought mix.
So think of chocolate as a brain food.
"People thank me all the time for telling them that chocolate is good for
them, ," says Vinson. "And really it is. I eat a little bit of chocolate
every day."
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Chocolate
Apr 2001
What's in the cocoa bean?
Cocoa is a rich source of procyanidin flavonoids, including epicatechins and
its derivatives. The antioxidant content is significantly higher than tea.
Oligomeric polyphenols in cocoa are stronger antioxidants than monomeric
polyphenols in tea. Oligomeric polyphenols inhibit reactive oxygen species
which can damage cell membranes leading to diseases such as
arteriosclerosis, cancer and the ageing process.
After an acute chocolate meal, plasma concentrations of epicatechin and
plasma antioxidant capacity increase compared to an acute white chocolate
meal. The increase in antioxidant capacity has been observed by a decrease
in lipid oxidation by-products. These results suggest that flavonoids can be
absorbed in quantities to influence the body’s defence parameters.
Any health benefits?
Antioxidants
Finally, some good news for chocolate lovers. It is not as bad for us as we
think. Recent studies have indicated that certain ingredients in chocolate
may play a role in preventing heart disease and cancer. Cocoa beans (one of
the main ingredients of chocolate) contain over 600 plant chemicals
including anti-oxidants which may protect against such diseases. Most of
these studies however, have been conducted on cocoa flavoured beverages, not
chocolate, which may be misleading. It is worth considering these studies,
however, as the findings prove to be very interesting.
Cocoa beans contain a type of phytochemical (anti-oxidant) called
polyphenols, which may have a role in the prevention of certain diseases.
Polyphenols help guard the body's cells from damage by free radicals. The
particular substances arousing so much interest are catechins which are a
type of polyphenol. It is these catechins which aid resistance against
degenerative diseases such as cancer and heart disease. Catechins can also
be found in fruits and vegetables, but the body needs to capture as many
different types of catechins as possible such as those found in tea and
chocolate. Dark chocolate has higher concentrations of catechins due to
higher levels of cocoa.
Feeding studies in human showed that LDL cholesterol in the blood taken 2
hours post consumption of chocolate was less likely to oxidise. One study
demonstrated that chocolate polyphenols affected platelet activation
proteins. When platelets which were exposed to chocolate polyphenols were
stimulated with epinephrine (known to cause platelet aggregation)
aggregation decreased, thus reducing the risk of blood clot formation. More
evidence is needed on how these findings translate to heart health.
Saturated fat
Although chocolate has often been condemned due to it's high saturated fat
content, the most predominant saturated fat in chocolate, stearic acid, does
not have the same cholesterolaemic effect as other saturated fats. The major
lipid in chocolate consists of oleic acid, stearic and palmitic acids.
Several studies indicate that stearic acid has a neutral effect on blood
lipids. However, stearic acid may activate clotting factor VII, may increase
lipoprotein Lp(a) concentration and may impair blood clot break down (fibrinolysis)
(AJCN 1999; 70: 951). However, cocoa butter appears to decrease platelet
activity, potentially beneficial for cardiovascular health. Stearic acid can
be found in meat fat, some margarines, and chocolate.
Dark chocolate versus milk chocolate
A recent study reported by Vlachopoulos at the 2004 European Society of
Cardiology demonstrated for the first time how chocolate improved the
function of blood vessels, allowing them to dilate, which would help prevent
the formation of potentially damaging clots. The study showed that eating
100 grams of dark chocolate improved vessel function in 17 healthy young
adults for at least three hours.
Dark chocolate contains high levels of an antioxidant called flavonoids.
This study sheds new light on how the mechanism might work, by protecting
blood vessels from the damaging effects of unstable oxygen compounds called
free radicals. Free radicals attack other atoms to stabilise themselves by
stealing an electron, and in the process can damage cells. The study did not
include milk chocolate, but the same benefits might not be gained from
eating milk chocolate. In 2003, scientists reported that dark chocolate
increased levels of antioxidants in the blood by nearly 20% where as milk
chocolate did not have the same effect. It is thought that milk may
interfere with the absorption of antioxidants from the chocolate.
Conclusion
We must still remember though that chocolate is a high-fat food and must be
consumed in moderation as part of an otherwise nutritious diet. It is also
advisable to obtain the benefits of catechins from cocoa (e.g. as hot
chocolate, mocha coffee) rather than chocolate because plain cocoa does not
have the fat content of chocolate. Traditional Mexican cuisine uses dark
chocolate in savoury white meat and vegetable dishes (see below). Chocolate
eaten this way has a lower energy density. Tea also contains catechins
(although not as many as chocolate and cocoa) and may therefore provide some
of the same benefits as consuming cocoa or chocolate without the fat.
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