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- Cocoa (Theobroma cacao)
- Chocolate
- Health Benefits
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Date:
05-15-2013 | HC# 041321-472
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Re: Review of the Health Benefits of Cocoa and Chocolate
Latif
R. Chocolate/cocoa and human health: a review. Neth J Med. March 2013;71(2):63-68.
While
for years chocolate had been considered an unhealthy food because of its fat
content and association with acne, high blood pressure, and other conditions,
it is now recognized as a beneficial substance, high in valuable
phytochemicals. The last decade has seen a flowering of research on the health
benefits of cocoa (Theobroma cacao)
and chocolate, which has yielded contradictory results. This review seeks to
interpret the science to help health professionals and the public to understand
the current state of knowledge.
Cocoa
was originally cultivated and processed by the Mayas, Incas, and Aztecs, and
was brought to Europe in the 16th century. Cocoa is currently grown primarily
in West Africa, Indonesia, and Sri Lanka. The beans are called cacao; after
roasting, it is called cocoa; and when the roasted beans are made into food
(e.g., sometimes with sugar and milk), it is called chocolate.
One
part of cocoa is a fraction called cocoa butter, which refers to the fat
content. The fat consists of 33% oleic acid (monounsaturated), 25% palmitic
acid (saturated), and 33% stearic acid (saturated). Even though it is a saturated
fat, stearic acid seems not to adversely affect the lipid profile. Cocoa also
contains the flavonoid catechins epicatechin, catechin, and procyanidin, at
levels higher than those found in tea (Camellia
sinensis) and red wine (from grapes; Vitis
vinifera). Because of its higher cocoa content, dark chocolate contains
more of these compounds than milk chocolate. The methylxanthines theobromine
and caffeine are also found in cocoa, along with several minerals, including potassium,
phosphorus, copper, iron, zinc, and magnesium.
The
first indication of cocoa's health benefits came from an examination of the
unusual pattern of low blood pressure among the Kuna Indians of Panama, whose
sole beverage was cacao beans boiled in water. When the Indians moved to the
city and their beverage consumption changed, high blood pressure became
apparent. Epidemiological studies have supported this phenomenon by showing an
inverse relationship between cocoa consumption and high blood pressure.
These
studies were paralleled with investigations into the particular benefits of
cocoa and chocolate.
Being
that chocolate is high in antioxidants (it is the third-highest source of
antioxidants for Americans) and therefore can reduce oxidative stress could be
a boon; however, one study has shown that the large increase in plasma antioxidant
capacity following chocolate consumption is probably due to an increase in uric
acid from fructose consumption, negating the theory.
The
examination of chocolate's effects on blood pressure has shown conflicting
results, which may relate to study design issues such as the use of small,
normotensive populations, different intake levels and forms, and short intake
durations. There is strong evidence for the mechanism that may be involved,
which is an increase in nitric oxide (NO) via upregulation of vascular
endothelial NO synthase, and inhibition of NO destruction.
There
is also good evidence for an effect of chocolate intake on platelets, involving
both a decrease in platelet aggregation and a reduction in platelet adhesion.
Effects
of chocolate on glucose metabolism have been elucidated, including a reduction
in insulin resistance (via improved NO levels), glucose levels, and insulin
response.
One study showed that
chocolate helps to alleviate stress by increasing the production of the calming
neurotransmitter, serotonin. Another study showed that chocolate consumption decreased
body weight by reducing the gene activity that governs fat synthesis and
increasing the gene activity that controls fat burning. Chocolate consumption
has also been shown to increase blood flow to the brain and was associated with
a reduced risk of stroke. Effects on tumor growth are preliminary and
ambiguous. It has been shown that chocolate intake may improve exercise
recovery times and help maintain glucose levels during exercise.
The adverse effects
of chocolate are mild and include heartburn and allergic reactions, though
these are rare. The sugar and triglyceride content of chocolate calls for an
alteration of diet or exercise when consuming chocolate daily; as a result, flavonoid-rich
cocoa products may be a better alternative to take advantage of its benefits.
—Risa Schulman,
PhD
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