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- Cocoa (Theobroma cacao)
- History
- Cardiovascular Health
| Date:
09-28-2012 | HC# 061224-457
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Re: The History and Health Benefits of Chocolate
Gianfagna TJ, Cooper
R. Cocoa-food and medicine of the gods. Altern
Complement Ther. 2012;18(2):84-90.
Chocolate has been
known and loved for many centuries as food, medicine, and currency. This
article explores the history of chocolate and the evidence for its health
benefits.
The cacao tree has
the Latin name Theobroma cacao, the
genus being a term for "food of the gods." It was first introduced to
the Europeans in the 1500s when Columbus went to Honduras and grew in
popularity when cane sugar was added. The Mayans and Aztecs drank it with chili
peppers, corn mash, vanilla, and other spices, and called it xocoatl, meaning "bitter water."
From here the word "chocolate" was derived. The native people drank
cocoa before long expeditions to improve their stamina.
A cocoa drink with
milk added began to be sold as medicine in England in 1687 by an English
botanist/MD, Sir Hans Sloane. Eating chocolate in its solid, milk chocolate form
did not evolve until Victorian times.
Cocoa grows in hot, humid
climates along the equator, mainly in Ghana,
the Ivory Coast, Brazil, Nigeria,
and Malaysia.
Harvested beans undergo a fermenting, drying, and roasting process which
results in a thick paste called cocoa liquor. The liquor is separated into the
fat component (cocoa butter) and the remainder (cocoa solids). Taking the cocoa
solids and adding back cocoa butter and sugar produces dark chocolate. The
cocoa butter without cocoa solids is used to make white chocolate. Chocolate
contains fiber (most of which is lost in processing); minerals, such as
magnesium, copper, and iron (providing a significant portion of the recommended
dietary allowance); and the monounsaturated fatty acid, oleic acid, and
saturated fatty acids, mainly palmitic acid and stearic acid.
The purple color of
the raw cocoa beans is due to the polyphenols, such as flavanols, and these are
lost in processing with alkali (called "dutching"). The main
flavanols are epicatechin and catechin; most chocolate drinks contain < 25
mg of flavanols. The bioavailability of flavanols has been studied, and it is
known that levels in the blood peak 2 hours post-consumption. Cocoa also contains the purine alkaloids
theobromine and caffeine. In recent years, athletes have been trying to
recapture the Aztec's stamina drink by consuming concentrated flavanols or isolated
epicatechin; however, the ancient drink differed in that it contained additional
flavanols, and no sugar or milk.
Meta-analyses have
shown that, at worst, chocolate has a neutral effect on serum cholesterol, with
ambiguous results across studies. The stearic fatty acid component of chocolate
does not increase total or low-density lipoprotein (LDL) cholesterol. Epidemiological
studies have shown that those eating the highest levels of chocolate had significantly
lower rates of all-cause mortality, cardiac death, cardiovascular disease,
heart failure, myocardial infarction, stroke, and diabetes. This is thought to
be due to down-regulating the inflammatory process and increasing nitric oxide
(NO). High-flavanol cocoa has been shown to increase NO and flow-mediated
dilation (an indicator of healthy circulation) in human studies.
The Kuna Indians, a
free-living island tribe off the coast of Panama, were studied by Norman
Hollenberg of Harvard Medical School. The main beverage of the Kuna is made
with unprocessed cacao beans. They have a very low incidence of blood pressure,
unless they move to the mainland and start drinking commercial cocoa beverages.
Then, their incidence of blood pressure matches the rest of the population. Dr.
Hollenberg found that the free-living Kuna had higher levels of NO in their
blood than mainland Kuna. NO also plays a role in proper platelet function, and
in 25 intervention studies, only cocoa has been shown to consistently benefit
platelet function. Intervention studies assessing effects on blood pressure
have been somewhat ambiguous, though several have shown a lowering effect for
both systolic and diastolic blood pressure in normotensive and hypertensive
individuals. Though 6.3 g/day of dark chocolate was somewhat effective, the
amount of chocolate consumed in other studies (46-105 g/day) would result in
weight gain. This would not be the case if cocoa were consumed instead.
The Kuna Indians were
also noted to have a low incidence of type 2 diabetes. The link between cocoa's
benefits for cardiovascular disease and insulin resistance comes through NO. Several
studies have shown a decrease in fasting glucose levels and insulin resistance,
but not in diabetic individuals, so conclusions about its therapeutic effects
are premature.
Cocoa may have effects on
the immune system because of its polyphenol content; however, adequate studies
in this area have yet to be undertaken.
The cocoa component phenethylamine
(PEA) is structurally and pharmacologically similar to catecholamines and
amphetamine, and cocoa may have neurological effects and improve cerebral blood
flow, though studies are only of a preliminary nature. Chocolate cravings
experienced by women at various parts of their menstrual cycle are possibly the
result of cultural rather than neurological factors. Improvements in mood and
cognitive ability may be related to the caffeine and theobromine content.
Benefits for skin
health and weight loss are two other areas of inquiry, but they have been only
preliminarily researched.
Cocoa and chocolate are
safe to eat, and studies indicate they do not cause problems with acne or
headaches as is commonly thought. There is an issue of high lead levels for
cocoa and chocolate typically used in the West. Weight gain from chocolate
consumption must always be taken into account when considering its regular
substantial use as a therapy.
—Risa Schulman,
PhD
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