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Agro FOOD Industry Hi Tech - vol 24(5) - September/October 2013
Functional drinks
Coconut oil:
a review
PADMINI SHANKAR*, SUMAN AHUJA, ALEXANDRA TRACCHIO
*Corresponding author
Department of Health & Kinesiology, Georgia Southern University,
PO Box 8076, Statesboro, GA 30460, USA
INTRODUCTION
Coconut, also known as Cocos Nucifera (1), a tree
known for its many nutritional and medicinal properties
has gained new found interest in western medicine. It is
believed that certain parts of the coconut, for example,
tender coconut water and kernel have medicinal
qualities including but not limited to antibacterial,
antiviral, antifungal, antioxidant, low glycemic index,
hepatoprotective, and immune system enhancement (1).
Coconut oil is very commonly used as a tropical edible
oil in many Asian cultures and is composed of almost 90-
95% saturated fatty acids (2). The health and nutritional
bene ts derived from coconut oil are both compelling and
contradictory, mainly due to its high saturated fat content
as relates to chronic diseases, especially those involving
the cardiac system (3).
Compositionally, coconut oil is derived from the dried
kernel or meat of coconut, also known as copra (3, 4).
Chemically, coconut oil primarily comprises of lauric
acid (47.5%), a low molecular weight saturated fatty
acid known to be a better alternative to other saturated
fatty acids, the kind found in butter (5). It has been
documented through the National Nutrition Survey of
2003 that in certain Asian cultures, wherein coconut oil
happens to be the primary source of cooking fat, the
incidences of hyperlipidemia, stroke and angina were
relatively low (5). In fact, a study reported that levels of
low density lipoprotein (LDL) appeared to be relatively
higher in individuals consuming saf ower oil and/or butter
as compared to those consuming coconut oil (5, 6).
While speculations regarding use of coconut oil and
its many potential medicinal bene ts have captured
the attention of the scienti c and clinical world here
in the United States, available clinical data suggesting
the many medicinal and nutritional properties of
consumption of coconut oil remain scarce. Although,
there are studies suggesting the many health bene ts
offered by consumption of coconut oil, most of these
studies have reported data derived from animal studies
or use of methodology including but not limited to
self-reporting through various dietary recalls; thus, with
this comprehensive review, we aim to shed light on
information related to the health bene ts of consuming
coconut oil.
HISTORY
Being touted as the world’s oldest oil, coconut oil has been
used as far back as 4000 years ago (7). It has been used
widely around the world, more particularly in the tropical
regions of Southern Asia and Paci c, Africa, Central America
and the Caribbean due to the abundant coconut palms
that grow there. Historical information claims that coconut
oil was the cure for illness in ancient India and China,
treating anything from infections and disease, to nausea and
toothaches. The creamy, soft texture of coconut oil has also
been used as a skin moisturizer and as hair therapy, aiding
in the prevention and treatment of dry skin and damaged
hair in the hot, tropic sun. Claimed to guarantee blemish and
infection free skin as well as strong bones, Samoan mothers
massage their children’s entire bodies frequently since
infancy with the miracle oil. Coconut oil is also rubbed on
the gums of babies to ease the pain during teething. In the
Philippines, coconut oil has been used as a muscle relaxer
and joint pain reliever. Jamaicans believed coconut oil to be
valuable to heart health, and drank it as a tonic whenever
sick (8). In India, coconuts, known as the “fruits of aspiration”,
are offered to the gods and have a prominent role in many
Indian religions (1).
Apart from the many medicinal and religious uses of
coconut oil, it also has been utilized in cooking. In Thailand
and Sri Lanka, as well as many other places around the
globe, coconuts make up most of the diet providing
nutritious sources of milk, meat, juice, and oil (8). After seeing
the bene ts of coconut oil, England and the United States
began producing and selling coconut oil as margarine and
butter, respectively (7). Coconut oil was taken off the US
market temporarily in 1986 when the American Soybean
Association instigated an anti-tropical oil campaign in order
to drive out the competition. This campaign, which targeted
both coconut and palm oils, was challenged in 1988 by
Harvard Medical School’s Dr. N.W. Istfan whose ndings
showed that coconut oil consumption did not increase the
risk for heart disease (9). It is categorized as a “functional
food” because of the oil’s rich supply of ber, vitamins, and
minerals. Due to the VCO’s strong stability, it is resistant to
free radical generation during intense temperature heating,
making coconut oil a very safe oil to cook with (7). Among
the health conscious consumers, coconut oil is gaining
wide spread popularity and is recommended as a healthy
KEYWORDS: virgin coconut oil; medium chain triglycerides; antimicrobial properties; cardiovascular health; metabolic syndrome
ABSTRACT: Coconut and its by-products have been used for centuries as culinary, cosmetic, and medicinal agents. More
recently, virgin coconut oil (VCO) is gaining recognition as a functional food due to its perceived health benefits. Virgin
coconut oil has a high proportion of medium-chain triglycerides, which unlike the long-chain triglycerides, are oxidized to
energy in the liver. In addition to its excellent antioxidant profile, coconut oil is said to have antimicrobial and hypolipidemic
properties too. This review focuses on the historical and functional aspects of coconut oil, with special emphasis on its health
properties.
Padmini Shankar
63
Functional drinks
include several components, such as diet, levels of physical
activity, psychological well-being, and other lifestyle
components like smoking. Of these, scienti c evidences
have indicated that dietary factors predominantly in uence
serum lipid concentrations (3). It is largely believed that
certain dietary fats lower low density lipoprotein (LDL) levels
while assisting in elevating higher density lipoprotein (HDL)
levels in the blood. Clinical evidences have also indicated
that risk for cardiovascular diseases increase dramatically
when serum LDL is easily oxidized (3). There is new found
interest in the cardio-protective effects of coconut oil as
reported by the Coconut Research Center. In one study,
coconut oil was reported to cause an increase in total
cholesterol levels; however, it is noteworthy that some of the
elevation in cholesterol levels is attributed to an increase
in HDL or good cholesterol (12). Therefore, it is essential to
understand the chemical composition of coconut oil in order
to extrapolate the health bene ts and clinical signi cance
of consuming coconut oil as a health promoting dietary
fat. Most coconut oil is extracted from the kernel or meat of
coconut, copra. Another form of extraction of coconut oil
involves using a wet process (involves extraction of coconut
oil directly from the coconut milk, done so under controlled
temperatures) and the resulting product is VCO, obtained
from coconut milk (3). Nevin et al. (2004) reported that VCO
has been shown to decrease total cholesterol, triglycerides,
and phospholipids. The researchers also reported that in
addition to an overall decrease in serum cholesterol, LDL,
and very low density lipoprotein (VLDL) levels were also
reduced after consumption of VCO. Furthermore, elevated
levels of HDL were found, thus enhancing the cardio-
protective bene ts of coconut oil. Lastly, this study also
found that VCO was capable of increasing antioxidant
enzyme activity, thus able to halt LDL oxidation, a primary
factor associated with atherosclerosis (3).
EFFECT OF COCONUT OIL ON CARDIOVASCULAR HEALTH
A recent study investigated the risk for cardiovascular
diseases upon consumption of coconut oil in the Philippines,
a country wherein coconut oil is abundantly used for
cooking purposes. Coconut
oil being extremely rich
in saturated fats, the
premise of this study was
to investigate the effects
of saturated fats in coconut
oil and its atherogenic
properties in a cohort of
1,839 Filipino women (5). The
results of this study indicated
that consumption of coconut
oil did not elevate serum
total cholesterol or serum
cooking oil and a source of alternative medicine.
Although a saturated fat, VCO is rich in medium chain
triglycerides (MCT), much different than the more common
long chain triglycerides (LCT). The difference between LCT
and MCT are in the way human bodies metabolize and
digest them (10). MCT do not require pancreatic lipase or
bile for digestion. Unlike LCT which are stored in our cells,
MCT are immediately transported to the liver and are
metabolized for energy (11). According to the Coconut
Research Center, MCT may actually help to lower the risk of
both atherosclerosis and heart disease (10).
ANTIMICROBIAL EFFECTS OF COCONUT OIL
For thousands of years, coconut oil has been found to
aid as an antibacterial, antifungal, antiviral, and anti-
dermatophytic agent. It has been used in Ayurvedic
medicine as well as in many other cultures worldwide. More
recently, studies have been conducted to test the effects
of coconut oil as an antimicrobial agent and ndings from
many support this thousand year old universal remedy.
By-products of coconut oil breakdown result in the
production of medium-chain fatty acids (MCFA) and
monoglycerides (MG). It is these MCFA and MG that confer
antimicrobial properties, by destroying pathogenic bacteria,
virus, fungi, and protozoa (12).
Coconut oil has been proven very successful and effective
against viruses that are lipid-coated, such as Epstein-Barr
virus, in uenza virus, leukemia virus, hepatitis C virus, and
cytomegalovirus (CMV), to name a few. It accomplishes this
by interfering and disrupting the virus membrane, assembly,
and maturation (1).
Oyi and colleagues studied the effectiveness of VCO in the
treatment of skin inoculations of Ps. Aeruginosa, E. coli, P.
vulgaris, B. subtilis, and C. albicans by converting the oil to
a cream. With the study’s success, there is now evidence
coconut oil can be formulated into creams to treat
bacterial and fungal infections. The effectiveness of VCO
as an antimicrobial agent is due to the active compound
monolaurin, a monoglyceride, which is a product of lauric
acid metabolization (13). Lauric acid is the predominant
fatty acid found in coconut oil. It is also found in breast milk
and helps to support healthy growth in breastfed infants and
has been shown to have many antimicrobial properties (14).
In today’s fast-paced and quick- x society, antibiotics
are overused and this indiscriminate use can lead to the
elimination of bene cial bacteria population in the gut.
This in turn can promote overgrowth of microorganisms
such as Candida and cause fungal infections. Because
VCO is a rich source of MCT and possesses antifungal
properties, a study in Nigeria focused on its effectiveness
as an antifungal agent and compared it to the action of
uconazole, the rst line of treatment for Candida albicans
infection. It was found that coconut oil was effective
against Candida at 100% concentration when compared
to uconazole. The study concluded coconut oil to be
a powerful alternative medicine, especially against
fungal species such as Candida (15).
HYPOLIPIDEMIC EFFECTS OF COCONUT
OIL
While cardiovascular disease
is on the rise, mainly, due to its
correlations with obesity, a growing
epidemic across the globe, risk
factors of cardiovascular diseases
Agro FOOD Industry Hi Tech - vol 24(5) - September/October 2013
64
Agro FOOD Industry Hi Tech - vol 24(5) - September/October 2013
Functional drinks
triglycerides. However, measurement of coconut oil intake
was calculated using self-reporting via two 24-hour dietary
recalls. Thus, due to the nature of the design practiced
by this study and lack of ability to control various external
and confounding variables, it would be safe to assume
that additional clinical trials are required before health
professionals are con dently able to prescribe coconut
oil consumption as it relates to being a cardio-protective
agent.
HEPATOPROTECTIVE EFFECTS OF COCONUT OIL
Liver is one of the largest and the most important organs in
the human body. The human liver is responsible for controlling
carbohydrate storage and metabolism, protein synthesis,
breakdown of red blood cells, and detoxi cation (16).
Despite the many advances in the medical eld, western
medicine has been unable to prevent and cure many
chronic conditions, one being offering protection from
much chemical and physiological damage to hepatic cells
resulting from routine exposure to different nutrients, drugs,
and environmental factors. In the most recent times, VCO
has gained a lot of popularity in the clinical eld, especially
in relation to its antioxidant and cardio-protective
properties. However, the understanding of the functional
properties of coconut oil clinically within the human body
requires sophisticated research methodologies. Data in
animals suggest that VCO may induce a hepatoprotective
effect in addition to the antiviral, anti-in ammatory, and
cardio-protective mechanisms. Zakaria et al. (2010)
investigated the hepatoprotective effects of VCO on
paracetemol induced liver damage in rats. The results
indicated that treatment of the damaged rat liver with
VCO signi cantly reduced liver damage concluding that
coconut oil may indeed offer some hepatoprotective
effects. Of course, the authors concluded that further
in-depth studies are required to observe similar results in
humans (16).
EFFECTS OF COCONUT OIL ON METABOLIC SYNDROME
While there is a surge in chronic diseases, mainly stemming
from presence of obesity, very little preventive cure is
available through western medicine. Type 2 diabetes,
hypertension, cardiovascular disease, and certain cancers
are all chronic conditions, risk for which can be increased by
what is deemed as metabolic syndrome, a cluster of factors
comprising of low levels of HDL, hyperglycemia, abdominal
obesity, hypertension, and high triglycerides (17).
Although the pathogenesis of metabolic syndrome
is complex, very little is known about the underlying
mechanisms and successful prevention and treatment
through western medicine. It has been observed that in
animals (mice models), consumption of MCT such as those
found in coconut oil may offer enhanced lipid oxidation
and greater energy expenditure. A recent study suggested
that consumption of MCT’s (coconut and milk) resulted in
greater elevation of post prandial oxygen consumption
in healthy men as compared to LCT (18). Hyperlipidemia,
a classic condition associated with metabolic syndrome
is one of the many leading causes of cardiovascular
diseases and while there are numerous synthetic drugs
available to treat the condition, none come without the
added risk of side effects, sometimes debilitating and
interfering with body processes and metabolism (16). It has
been demonstrated that MCT’s could potentially offer a
therapeutic advantage in the treatment of hyperlipidemia
and metabolic syndrome, and in addition, MCT’s when
tested in animal models, offers promising results as far
as improving insulin sensitivity and type 2 diabetes,
both conditions associated with presence of metabolic
syndrome (17).
Of the many chronic conditions associated with metabolic
syndrome, waist circumference can be used as an
indicator of abdominal obesity (19) resulting in health issues
such as type 2 diabetes, certain cancers, hypertension, and
infertility, especially in women. A recent study investigated
the effects of supplementation with dietary coconut oil in
women who presented with abdominal obesity determined
by their waist circumference. The study population was
provided with either soybean oil or coconut oil. While
reductions in body mass index (BMI) were observed in both
groups, only the women supplemented with coconut oil
presented reductions in waist circumference. The study
concluded that coconut oil supplementation offered
protection against dyslipidemia, an imbalance of serum
lipids associated both with metabolic syndrome and
abdominal obesity (19). Liau et al. (20) studied the ef cacy
of VCO in weight reduction and lipid pro le of 20 Malay
people. While no improvements were seen in the lipid
levels, decrease in visceral adiposity as measured by waist
circumference was seen, especially in men.
CONCLUSION
There is renewed emphasis on incorporating heart-healthy
fats in our diet today. Virgin coconut oil with its versatility
as a cooking medium and limited pharmacotherapeutic
properties is gaining popularity in modern society. However,
further research is needed to provide conclusive evidence
on its clinical applications. Until such time it is important to
adhere to dietary guidelines, which recommend moderate
amounts of healthy fats in our daily diet.
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