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Special Article
Coconut oil consumption and cardiovascular risk factors
in humans
Laurence Eyres, Michael F. Eyres, Alexandra Chisholm, and Rachel C. Brown
Coconut oil is being heavily promoted as a healthy oil, with benefits that include
support of heart health. To assess the merits of this claim, the literature on the
effect of coconut consumption on cardiovascular risk factors and outcomes in
humans was reviewed. Twenty-one research papers were identified for inclusion in
the review: 8 clinical trials and 13 observational studies. The majority examined the
effect of coconut oil or coconut products on serum lipid profiles. Coconut oil gener-
ally raised total and low-density lipoprotein cholesterol to a greater extent than cis
unsaturated plant oils, but to a lesser extent than butter. The effect of coconut
consumption on the ratio of total cholesterol to high-density lipoprotein cholesterol
was often not examined. Observational evidence suggests that consumption of co-
conut flesh or squeezed coconut in the context of traditional dietary patterns does
not lead to adverse cardiovascular outcomes. However, due to large differences in
dietary and lifestyle patterns, these findings cannot be applied to a typical Western
diet. Overall, the weight of the evidence from intervention studies to date suggests
that replacing coconut oil with cis unsaturated fats would alter blood lipid profiles
in a manner consistent with a reduction in risk factors for cardiovascular disease.
INTRODUCTION
Coconut oil has been an important edible oil for the
food industry for many years and is normally termed or
classified as a lauric oil, a tropical oil, or a confectionery
fat.
1
The usual commercial product is either refined,
bleached, and deodorized coconut oil or, more recently,
virgin (unrefined) coconut oil.
2
The production of co-
conut oil has been increasing worldwide. In 2010,
3.5 million metric tons were produced, with the major
producers being the Philippines (1.7 million metric
tons), Indonesia (0.7 million metric tons), and India
(0.5 million metric tons).
3
Of this total, around 2.0 mil-
lion metric tons were exported, with the major exporter
being the Philippines. Consumption in the United
States in 2010 was reported as 0.4 million metric tons,
with an average consumption of 1.28 kg per capita per
annum. Consumption in the European Union was re-
ported as 0.6 million metric tons, with a similar average
consumption of 1.3 kg per capita per annum.
One of the advantages of coconut oil is its resis-
tance to oxidation and polymerization, which makes it
a stable oil for cooking. For example, it is suitable for
single-use shallow frying, although it is not recom-
mended for continuous deep-fat frying because of its
low smoke point, which may lead to the production of
potentially carcinogenic substances upon overheating.
4
Because of its high content of saturated fatty acids
(92%), coconut oil has always been classified, along
with butter, palm oil, and animal fats, as a source of sat-
urated fat to be consumed at low levels in the diet
(Table 1).
5–7
In recent years, numerous claims on
Affiliation: L. Eyres is with the NZIC Oils and Fats Specialist Group, New Zealand Institute of Chemistry, Auckland, New Zealand. M. Eyres is
with ECG Ltd, Point Wells, Auckland, New Zealand. A. Chisholm and R. Brown are with the Department of Human Nutrition, University of
Otago, Dunedin, New Zealand.
Correspondence: L. Eyres, NZIC Oils and Fats Group, 127 Point Wells Rd, Point Wells, RD 6 Warkworth, Auckland 0986, New Zealand. Email:
eyresy@gmail.com. Phone: þ64-9-4229573.
Key words: cardiovascular disease, cholesterol, coconut, lauric acid, medium-chain triglycerides.
V
CThe Author(s) 2016. Published by Oxford University Press on behalf of the International Life Sciences Institute. All rights reserved. For
Permissions, please e-mail: journals.permissions@oup.com.
doi: 10.1093/nutrit/nuw002
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websites and in the commercial literature have likened
coconut oil to medium-chain triglycerides, asserting
that it behaves atypically compared with other foods
high in saturated fat and is beneficial for human health.
2
Research on manufactured medium-chain triglycerides
in the literature cannot be applied to coconut oil be-
cause the triglycerides predominant in coconut oil
are different in their structure, absorption, and
metabolism.
A comparison of the fatty acid composition of co-
conut oil, medium-chain triglycerides (derived from co-
conut oil or palm kernel oil), and butterfat is shown in
Table 2.
8–10
Medium-chain triglyceride oils are made
predominantly of C8:0 (caprylic) and C10:0 (capric)
fatty acids. Research on medium-chain triglyceride oils
has been focused on these synthesized esters of C:8 and
C:10 fatty acids.
8
Both are classified as medium-chain
fatty acids. The main fatty acid in coconut oil is lauric
acid (C12:0). Lauric acid can be classified as either a
medium-chain or a long-chain fatty acid. In terms of di-
gestion and metabolism, however, it behaves more as a
long-chain fatty acid because the majority of it (70%–
75%) is absorbed with chylomicrons.
11
In comparison,
95% of medium-chain fatty acids are absorbed directly
into the portal vein.
12
Medium-chain fatty acids are more water soluble
than long-chain fatty acids and are solubilized in the
aqueous phase of the intestinal contents without form-
ing micelles, thereby undergoing faster absorption.
13
Medium-chain fatty acids are also weak electrolytes and
are highly ionized at neutral pH, which further in-
creases their solubility.
14
This marked difference in sol-
ubility occurs at chain lengths of C:10 and less, which
therefore excludes lauric acid.
When fatty acids are combined into triglycerides, the
triglycerides themselves can also be termed medium-chain
Table 1 Composition of coconut products
Coconut product Component (per 100 g of product)
Water Energy Protein Fat SFA CHO Fiber
(g) (kJ) (g) (g) (g) (g) (g)
Raw coconut flesh
a
45 1470 3.2 36 33 3.6 7.7
Coconut, desiccated
a
2 2530 5.6 62 58 6.1 19.2
Coconut cream, canned
a
71 858 1 20 19 3.7 0.6
Coconut oil (EV or RBD)
b
0 3700 0 100 92 0 0
Hydrogenated coconut oil (CF92)
b
0 3700 0 100 100 0 0
Coconut water
c
95 80 0.7 0.2 0 3.7 1.1
Abbreviations: CF, confectionery fat; CHO, carbohydrate; EV, extra virgin; RBD, refined, bleached, and deodorized; SFA, saturated fatty
acid.
a
The Concise New Zealand Food Composition Tables, 11th ed.
5
b
USDA National Nutrient Database for Standard Reference, Release 27.
6
c
Yong et al. (2009).
7
Table 2 Comparison of the properties of coconut oil, medium-chain triglycerides, and butterfat
Property Coconut oil
a
Hydrogenated
coconut oil
b
MCTs derived from
coconut oil or palm
kernel oil
c
Butterfat
b
Butyric acid 4:0 (percentage of TFAs) 0 0 0 4.3
Caproic acid 6:0 (percentage of TFAs) 1 <1<2 2.3
Caprylic acid 8:0 (percentage of TFAs) 9 5.4 50–80 1.4
Capric acid 10:0 (percentage of TFAs) 7 5.8 20–50 2.8
Lauric acid 12:0 (percentage of TFAs) 47 48.3 <3 3.1
Myristic acid 14:0 (percentage of TFAs) 16.5 18.8 <19
Palmitic acid16:0 (percentage of TFAs) 7.5 9.8 0 22
Stearic acid 18:0 (percentage of TFAs) 3 11.7 0 15
Oleic acid 18:1 cis (percentage of TFAs) 6.4 0.2 0 26
Elaidic acid 18:1 trans (percentage of TFAs) 0 0 0 5
Linoleic acid 18:2 (percentage of TFAs) 1.5 0 0 1.9
Total SFAs (percentage of TFAs) 92 99.8 100 60
Triglycerides, carbon number range C28–C52 C28–C52 C24–C32 C28–C54
C24–C30 content <4% <4% 95% <1%
Mean MW of triglycerides 638 638 512 690
Physical characteristics Solid at ambient
temperature
Melts at 36C Liquid at all
temperatures
Solid at ambient
temperature
Abbreviations: MCTs, medium-chain triglycerides; MW, molecular weight; SFAs, saturated fatty acids; TFAs, total fatty acids.
a
Eyres (1979).
9
b
Williams et al. (1972).
10
c
Bach and Babayan (1982).
8
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or long-chain. Medium-chain triglycerides have a total
carbon number of C24:0 to C30:0. Only around 4% of the
triglycerides in coconut oil are of this length. Triglycerides
containing lauric acid have a higher molecular weight
and are metabolized differently than the lower-molecular-
weight triglycerides, which contain only C8 and C10
chains (medium-chain triglycerides). The mean molecu-
lar weight of triglycerides in coconut oil is 638, whereas
that of medium-chain triglyceride oils is 512. The lower
molecular weight of medium-chain triglycerides facilitates
the action of pancreatic lipase. Consequently, medium-
chain triglycerides are hydrolyzed faster and more com-
pletely than longer-chain triglycerides.
8
It is therefore
inaccurate to consider coconut oil to contain either pre-
dominantly medium-chain fatty acids or predominantly
medium-chain triglycerides. Thus, the evidence on me-
dium-chain triglycerides cannot be extrapolated to coco-
nut oil.
Epidemiological evidence from populations who
consume substantial amounts of coconut is frequently
cited as evidence that coconut oil does not have nega-
tive effects on cardiovascular health. It is important to
note, however, that most indigenous populations have
consumed either coconut flesh or squeezed coconut
cream.
15
The extraction and use of coconut oil in edible
applications is a relatively recent phenomenon.
Furthermore, when earlier data were collected, coconut
products were consumed as part of a traditional diet,
which was characterized by a low intake of processed
foods. Subsequent to this, a large shift toward the
Western diet has occurred among many indigenous
populations, as evidenced by imports of unhealthy
foods such as corned beef, fast food, and processed in-
gredients, leading to huge increases in obesity and poor
health.
16
The purpose of this narrative review, therefore, is
to systematically assess the research available on the
consumption of coconut oil, coconut milk, or coconut
cream in humans, along with the effect of these prod-
ucts on cardiovascular disease (CVD) or related risk
factors.
Search strategy
A search was conducted of the MEDLINE and Scopus
databases to the end of 2013 for English-language re-
search articles or reviews of studies performed in hu-
mans. The search terms used were “coconut” or “cocos
nucifera” in the title, abstract, or keywords. To ensure
all relevant articles were identified, search terms related
to CVD or risk factors were not included in the search.
Studies were included if they were conducted in
humans and met the following criteria: the study was
related to consumption of edible coconut, coconut oil,
squeezed coconut, coconut milk, or coconut cream; co-
conut was the main intervention or focus of analysis;
and outcomes were relevant to CVD.
Studies were excluded if they were published as let-
ters, conference abstracts, opinion pieces, nonsyste-
matic reviews, or books. Articles were further excluded
if the research was related to medium-chain triglycer-
ides (rationale provided above); if they reported animal
or ex vivo studies; if the study was related to the history
of coconut production or use; if coconut was part of a
mixed intervention and it was not possible to determine
its individual impact; if the study was conducted in a
special clinical population, e.g., patients with liver cir-
rhosis or formula-fed infants; if study outcomes such as
lipid profiles were a minor part of the experimental re-
sults and were not a major objective of the study; if the
study was also a drug trial; if the study investigated the
effect of lauric acid rather than coconut; or if the study
lacked a control group.
All articles were extracted into an EndNote library
and duplicate studies removed. Exclusion criteria were
applied by first screening titles and then screening ab-
stracts, after which full papers were reviewed as neces-
sary. Additional articles were obtained by manually
searching bibliographies and coconut-related websites.
The database search identified 1528 unique articles
(Figure 1). A further 4 papers were identified from bib-
liography and Web searches, yielding a total of 1532 to
be examined. Screening by title and abstract review re-
duced the number to 51. The first 2 authors reviewed
full texts of the remaining articles against the exclusion
criteria and made consensus decisions about inclusion
and exclusion. One paper was identified during peer re-
view and was added. A total of 21 papers were identified
for inclusion in this review.
Epidemiological evidence Indigenous populations who
consume significant amounts of coconut products in-
clude those of India, Sri Lanka, the Philippines,
Polynesia, and Melanesia.
17–21
Their health statistics are
often quoted as evidence that consuming coconut oil
poses no risk of CVD.
22
However, observational studies
in these population groups cannot show causation and
are prone to confounding because many different fac-
tors can simultaneously affect a specific health outcome
or indicator. Furthermore, cross-sectional studies can-
not show a temporal sequence because measures are
taken at a single point in time. They are highly prone to
recall bias and reverse causation. Observational studies
also have inherent limitations when used for dietary as-
sessment because they have a strong bias toward under-
estimation of habitual energy intake. Of the
observational studies identified for inclusion in this re-
view, the 8 key papers are discussed below.
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The Pukapuka and Tokelau Island study by Prior
et al.
20
found a low incidence of CVD in the popula-
tions of these two islands, despite a large portion of en-
ergy intake (34% among Pukapukans and 63% among
Tokelauans) and dietary fat intake being from coconut
flesh. It has been reported that the diets of these two
populations were low in sugar and high in fiber-rich
foods, resulting in low cholesterol levels (4.5 mmol/L
and 4.6 mmol/L in Pukapukans and Tokelauans, respec-
tively). The higher saturated fat intake among the
Tokelauans was associated with significantly higher to-
tal cholesterol (0.87–1.00 mmol/L) among the different
age groups compared with the Pukapukans (all
P<0.05).
Forty years ago, a study of Tokelauans who mi-
grated to and had lived in New Zealand for approxi-
mately 7 years was conducted.
15
Lipid profiles and diets
for 1200 residents of New Zealand were compared with
those of 800 people still living in Tokelau. For the male
migrants, whose diet and lifestyle had changed, plasma
Figure 1 PRISMA flow diagram of the literature search
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total cholesterol was higher by approximately 0.4 mmol/
L (4.7–5.1 mmol/L), low-density lipoprotein cholesterol
(LDL-C) was higher by 0.4 mmol/L (3.0–3.4 mmol/L),
and high-density lipoprotein cholesterol (HDL-C) was
lower by 0.06 mmol/L (1.22–1.16 mmol/L).
15
For the
people of Tokelau, 50% of their energy intake was from
fat, predominantly coconut, either as grated coconut
flesh or as coconut cream. Their diet consisted primar-
ily of coconut, breadfruit, and fish. Coconut oil was not
consumed per se. For the migrants who moved to New
Zealand, their lifestyle and entire diet changed to in-
clude less fish and considerably more dairy products,
meat, and sugar. Thus, the differences cannot be attrib-
uted to the presence or absence of coconut oil.
The Kitava studies examined cross-sectional age re-
lations of cardiovascular risk factors in 203 Melanesian
people between the ages of 20 and 86 years in Papua
New Guinea.
19,23,24
Coconut is a staple food of the
Kitavans, who have a very low incidence of CVD. Fat
intake (mainly from coconut) among Kitavans as a per-
centage of energy was low, at 21%. The Kitavan diet
consisted of whole coconut, tubers, fish, and fruit. The
average total cholesterol was reported as 4.7 mmol/L,
with LDL-C being 3.1 mmol/L. Life expectancy in this
study was most highly correlated with body mass index,
the mean of which for those studied was 20 kg/m
2
.
A cross-sectional study of 1508 Samoans living in
American and Western Samoa compared people con-
suming a traditional diet, which included coconut prod-
ucts, with those consuming a Western-style diet.
17
The
Western diet was associated with an increased incidence
of metabolic syndrome and, therefore, an increased risk
of developing CVD. These authors did not measure to-
tal cholesterol or LDL-C but focused on components of
the metabolic syndrome: abdominal obesity, hyperten-
sion, hypertriglyceridemia, low HDL-C, and elevated
fasting glucose. They concluded that the results of this
study provide evidence of the potential protective effect
of a neotraditional eating pattern in American Samoa
and Samoa. However, they state that, given the cross-
sectional nature of this study, the results should be con-
firmed in a prospective study and in clinical trials to
separate the effects of specific nutrients from the influ-
ence of the surrounding dietary pattern. The neotradi-
tional dietary profile was characterized by a high intake
of coconut products and seafood and a low intake of
processed foods, including potato chips, rice, and soft
drinks.
Coconut consumption is associated with higher
levels of serum HDL-C in epidemiological studies, and
claims of coconut being beneficial to heart health have
been attributed to this effect.
22
An analysis of the results
of a longitudinal cohort study of 1839 Filipino women
aged 35–69 years by Feranil et al.
25
reveals that, while
HDL-C levels did indeed rise with an increase in coco-
nut oil intake (1.01–1.09 mmol/L, P¼0.001), total cho-
lesterol (4.63–5.02 mmol/L, P¼0.001), and LDL-C
(2.97–3.23 mmol/L, P¼0.001) also rose. The serum tri-
glyceride levels of the participants rose with increasing
coconut oil intake (1.43–1.51 mmol/L, P¼0.001). The
ratio of total cholesterol to HDL-C was unaffected by
coconut intake (P¼0.81). When viewed as a whole,
these results do not indicate either a beneficial or a det-
rimental effect on serum lipid profiles.
Sabitha et al.
26
conducted a cross-sectional study in
140 middle-aged Indian men with and without type 2
diabetes who self-reported typically consuming coconut
oil or sunflower oil as 13% to 20% of their total energy
intake over the past 6 years. Lipid profiles and oxidative
stress parameters were compared between the groups
and did not show any statistically significant differences
between coconut oil and sunflower oil. While the au-
thors concluded that type of dietary fat may not be a
major contributory factor to oxidative stress in this
population, the observational nature of the study design
does not allow any firm conclusions to be drawn.
Population studies have been performed in several
other countries: 2 studies from Tanzania looked at obe-
sity and dyslipidemia,
27,28
1 each from Indonesia and
India looked at coronary heart disease,
18,29
and 1 from
India examined hypertension.
30
Confounding factors
between study groups, such as smoking and sugar con-
sumption, make it unclear whether coconut in the diet
has any positive or negative effect on CVD and its risk
factors.
Clinical trials and intervention studies Eight interven-
tion studies met the inclusion criteria (Table 3).
31–38
Four were crossover trials,
31,33,37,38
3 were sequential
feeding studies,
32,34
and 1 was a randomized parallel
community-based trial.
35
Two studies were conducted
in New Zealand,
31,32
2 in the United States,
33,37
2 in Sri
Lanka,
34,35
and 2 in Malaysia.
36,38
The primary out-
comes were related to serum lipids (n ¼8)
31–38
and
markers of inflammation or oxidative stress (n ¼1).
38
Coconut and blood lipids and lipoproteins
Cox et al.
31
conducted a randomized crossover trial to
assess the effects of coconut oil, butter, and safflower oil
on lipids and lipoproteins in moderately hypercholes-
terolemic individuals. Twenty-eight participants (13
men, 15 women) followed three 6-week experimental
diets of similar macronutrient distribution with the 3
different test fats providing 50% of total dietary fat. Fat
as a percentage of energy ranged from 35% to 37%.
After both the butter and the coconut oil interventions,
total cholesterol (6.8 mmol/L and 6.4 mmol/L,
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Table 3 Summary of intervention studies investigating coconut oil
Reference Study design
(country)
Participants Intervention Comparator Outcome (mmol/L, except where specified)
Cox et al.
(1995)
31
Randomized
crossover trial
(New Zealand)
n¼28 (13 M, 15 F) adults,
29–67 y, TC 5.5–
7.9 mmol/L, TG
<3 mmol/L
Three diets, each followed for
a 6-wk period. Total fat sup-
plied 36% energy and carbo-
hydrate 47% energy.
Coconut diet: SFA from coco-
nut oil supplied 20% of
energy
Butter diet: SFA from butter
supplied 20% of total
energy.
Safflower diet: 10% energy
from safflower oil; SFA and
PUFA each 10% total energy
TC: butter (6.8 60.9) >coconut oil (6.4 60.8) >safflower
oil (6.1 60.8), all significantly different
LDL: butter (4.5 60.8) >coconut oil (4.2 60.8) >safflower
oil (3.9 60.7), all significantly different
HDL: N/S differences
TG: butter (2.0 61.3) >coconut oil (1.8 61.0) >safflower
oil (1.7 61.0)
(N/S in men for coconut oil vs safflower oil)
ApoA-I: significantly higher for coconut oil and butter vs
safflower oil (N/S in women)
ApoB: significantly lower for safflower oil vs coconut oil
CETA: significantly higher for butter vs safflower oil (N/S in
men)
Cox et al.
(1998)
32
Sequential feed-
ing trial (New
Zealand)
n¼41 (24 M, 17 F) healthy
Pacific Islanders living in
New Zealand
39 g coconut oil to supply 17 g
lauric acid per day for 6 wk.
Total fat supplied 36% en-
ergy (84 g) and carbohydrate
47% energy
Butter (39 g) and safflower oil
(24 g) to provide 17 g pal-
mitic acid and 17 g linoleic
acid for 6 wk each
Lathosterol/cholesterol ratio: coconut oil
(1.09 60.34) <safflower (1.14 60.49) <butter
(1.24 60.24), butter significantly different from coconut
and safflower
TC: butter (5.61 60.96) >coconut oil (5.47 60.91) >saf-
flower oil (5.1 60.93), butter and coconut oil signifi-
cantly different from safflower oil
VLDL: safflower oil (0.45 60.45) >coconut oil
(0.41 60.36) >butter (0.34 60.18) (N/S)
LDL: butter (4.08 60.89) >coconut oil (3.79 60.75) >saf-
flower oil (3.5 60.84), all significantly different
HDL: safflower oil (1.06 60.21) <butter
(1.16 60.24) <coconut oil (1.21 60.27), butter and co-
conut significantly different from safflower oil
TG: butter (1.86 60.89) >safflower oil (1.77 61.25) >co-
conut oil (1.61 60.93) (N/S)
ApoA-I (g/L): safflower oil (1.15 60.14) <butter
(1.23 60.18) <coconut oil (1.33 60.28), butter and co-
conut significantly different from safflower oil
ApoA-II (g/L): coconut oil (0.35 60.08) ¼safflower oil
(0.35 60.08) >butter (0.34 60.08) (N/S)
ApoB (g/L): butter (1.00 60.22) >coconut oil
(0.87 60.38) >safflower oil (0.76 60.18), butter signifi-
cantly higher than coconut oil and safflower oil
Mendis et al.
(2001)
35
Randomized
feeding trial
(Sri Lanka)
n¼54 (42 M, 12 F) Sri
Lankans, half of whom
were
hypercholesterolemic
Phase 1: All subjects reduced
fat from 31% to 25% of total
energy by reducing coconut
fat from 17.8% total energy
to 9.3% over 8 wk.
Phase 2: Subjects reduced fat
from 25% to 20% by
Phase 2: Same fat intake as
Diet A, with the addition of
3.3% energy from soyabean
and sesame oils to a total of
24% total energy from fat
for 52 wk (PUFA:SFA ra-
tio ¼1.1) (Diet B)
In both phases, fat was replaced with carbohydrate, and
energy intakes decreased.
Phase 1:
TC: 0.6, significantly different vs baseline
LDL: 0.5, significantly different vs baseline
HDL: no change
TC:HDL ratio: 0.3 (N/S)
(continued)
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Table 3 Continued
Reference Study design
(country)
Participants Intervention Comparator Outcome (mmol/L, except where specified)
reducing coconut fat from
9.3% to 4.7% over 52 wk
(PUFA:SFA ratio ¼0.7) (Diet
A)
TG: 0.2 (N/S)
Change from phase 1 at 12 mo (group A vs group B):
TC: 4.2% vs 4.0% (N/S)
LDL: 11% vs 16% (significantly different)
HDL: þ33.6% vs þ32.8% (N/S)
TC:HDL ratio: 23.8% vs 27.1% (N/S)
TG: 6.5% vs 8.2% (significantly different)
Mendis &
Kumaras-
underam
(1990)
34
Sequential feed-
ing trial (Sri
Lanka)
n¼25 healthy adult male
prison inmates (20–26 y),
normal BMI
70% of fat from coconut fat for
8 wk (PUFA:SFA ra-
tio ¼0.25). Total fat pro-
vided 30% of energy
70% of fat from soyabean oil
for 8 wk (PUFA:SFA ra-
tio ¼4.0). Total fat provided
30% of energy
TC: coconut oil (4.64 60.37) >soyabean oil (3.68 60.42)
(significantly different)
LDL: coconut oil (2.84 60.37) >soyabean oil (2.27 60.36)
(N/S)
HDL: soyabean oil (0.94 60.26) <coconut oil 1.14 60.27)
(N/S)
TG: coconut oil (1.45 60.41) >soyabean oil (1.06 60.42)
(N/S)
Changes from baseline were statistically significant for
soyabean oil but N/S for coconut oil
Ng et al.
(1991)
36
Sequential feed-
ing trial
(Malaysia)
n¼83 (61 M, 22 F),
healthy, normolipidemic
adults
Approximately 75% of energy
was from fat from coconut
oil. Participants were ran-
domized to 1 of 3 dietary
sequences:
Approximately 75% of energy
was from fat from palm
olein or corn oil
Sequence 1:
TC: coconut oil (4.93 61.29 [period 1] and 5.07 60.87 [pe-
riod 3]) >palm oil (4.00 60.87), significantly different
LDL: coconut oil (3.18 61.20 [period 1] and 3.31 60.86
[period 3]) >palm oil (2.52 60.77), significantly different
HDL: palm oil (1.08 60.27) <coconut oil (1.35 60.29 [pe-
riod 1] and 1.35 60.35 [period 3]), significantly different
LDL:HDL ratio: coconut oil (2.46 61.26 [period 1] and
2.50 61.07 [period 3]) >palm oil (2.40 61.03), N/S
TG: coconut oil (0.89 60.29 [period1] and 0.88 60.36 [pe-
riod 3]) ¼palm oil (0.88 60.36), N/S
Sequence 2:
TC: coconut oil (4.90 60.99 [period 1] and 5.19 60.83 [pe-
riod 3]) >corn oil (3.15 60.60), significantly different
LDL: coconut oil (3.09 60.89 [period 1] and 1.78 60.49
[period 3]) >corn oil (3.39 60.73), significantly different
HDL: corn oil (0.99 60.21) <coconut oil (1.34 60.34 [pe-
riod 1] and 1.43 60.34 [period 3]), significantly different
LDL:HDL ratio: coconut oil (2.40 61.06 [period 1] and
2.37 60.88 [period 3]) >corn oil (1.81 60.60), signifi-
cantly different
TG: corn oil (0.86 60.38) <coconut oil (0.94 60.38 [pe-
riod 1] and (0.80 60.27) [period 3]), significant differ-
ence between coconut oil and corn oil for period 1
Sequence 3:
N/S for any of the indices
1. Coconut oil–palm oil–coco-
nut oil
2. Coconut oil–corn oil–coco-
nut oil
3. Coconut oil throughout
(continued)
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Table 3 Continued
Reference Study design
(country)
Participants Intervention Comparator Outcome (mmol/L, except where specified)
Reiser et al.
(1985)
37
Randomized
crossover trial
(USA)
n¼19 normolipidemic
male medical students
(12 completed all 3 diets)
60% of fat from coconut oil,
beef fat, or safflower oil,
each for 5 wk. 35% of total
energy from fat
Habitual diet at baseline and
during washout periods
TC: coconut oil (4.34 60.08) >beef fat (4.01 60.08) >saf-
flower oil (3.65 60.08), all significantly different
LDL: coconut oil (2.84 60.11) >beef fat
(2.53 60.12) >safflower oil (2.33 60.12), coconut oil
significantly different from safflower oil
HDL: beef fat ¼safflower oil (1.03 60.03) <coconut oil
(1.19 60.03), beef fat and safflower oil significantly dif-
ferent from coconut oil
TG: beef fat (0.99 60.04) >coconut oil (0.88 60.04) >saf-
flower oil (0.81 60.04), significant difference between
beef fat and coconut oil
Fisher et al.
(1983)
33
Crossover trial
(USA)
n¼9 normolipidemic
males (18–37 y)
Mostly formula diet containing
31% fat as coconut oil (with
and without added choles-
terol) for 9 d
Mostly formula diet containing
31% fat as corn oil (with and
without added cholesterol)
for 9 d
Coconut significantly increased TC, VLDL, IDL þLDL, and
HDL cholesterol as well as TG when compared with
corn oil.
In comparison with ad libitum (baseline) diets:
TC: coconut oil (4.45 60.72) >ad libitum
(3.88 60.47) >corn oil (2.97 60.31)
VLDL: coconut oil (0.59 60.18) >ad libitum
(0.36 60.16) >corn oil (0.34 60.13)
IDL þLDL: coconut oil (2.82 60.72) >ad libitum
(2.51 60.54) >corn oil (1.76 60.39)
Total TG: coconut oil (1.04 60.34) >corn oil
(0.61 60.12) >ad libitum (0.59 60.18)
Coconut oil shifted ApoE toward lower-density lipopro-
teins (VLDL, IDL, and LDL). Subgroup analysis showed
no effect of ApoE phenotype on variables measured
Voon et al.
(2011)
38
Randomized
crossover trial
(Malaysia)
n¼45 (36 F, 9 M) normal
weight and overweight
healthy adults (average
age 30 y)
Meals for 5 wk provided 30%
energy from fat, two-thirds
of which was from coconut
oil (20% total energy)
Meals for 5 wk provided 30%
energy from fat, two-thirds
of which was from palm oil
or extra virgin olive oil
TC: coconut oil (4.95 60.69) >palm oil (4.81 60.74) >ol-
ive oil (4.65 60.71), significant difference between coco-
nut oil and olive oil
LDL: coconut oil (3.30 60.75) >palm oil
(3.20 60.71) >olive oil (3.06 60.64), significant differ-
ence between coconut oil and olive oil
HDL: olive oil (1.28 60.23) <palm oil (1.31 60.26) <co-
conut oil (1.37 60.30), significant difference between co-
conut oil and olive oil
TC:HDL ratio: palm oil (3.69 60.90) >coconut oil
(3.65 60.95) >olive oil (3.63 60.93) (N/S)
(continued)
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respectively) and LDL-C (4.5 mmol/L and 4.2 mmol/L,
respectively) were significantly higher than after the saf-
flower oil intervention (total cholesterol, 6.1 mmol/L;
LDL-C, 3.9 mmol/L), and butter raised both outcome
measurements significantly more than coconut oil
(P<0.001). There was no statistically significant differ-
ence in HDL-C levels between interventions.
Concentrations of triglycerides were significantly lower
after the coconut oil (P¼0.01) and safflower oil
(P¼0.02) interventions compared with the butter inter-
vention, with no difference between coconut oil and
safflower oil (P¼0.48).
In a larger trial, Cox et al.
32
carried out a sequential,
nonrandomized feeding experiment in 41 healthy peo-
ple of Pacific ethnicity to assess the effects of coconut
oil, butter, and safflower oil on blood lipids and lipo-
proteins. The participants consumed each of the 3 test
diets for 6 weeks. Fat was consumed as 36% total en-
ergy, with test fats providing 46% of dietary fat intake.
The authors confirmed their earlier findings,
31
in that
total cholesterol and LDL-C levels were highest with the
butter diet (5.61 mmol/L and 4.08 mmol/L, respectively)
and lowest with the safflower oil diet (5.1 mmol/L and
3.5 mmol/L, respectively), with coconut oil in between
the two (5.47 mmol/L and 3.79 mmol/L, respectively).
Total cholesterol and LDL-C levels were significantly
higher in both the butter and the coconut oil interven-
tions compared with the safflower oil intervention
(P<0.01) but did not differ significantly between butter
and coconut oil. Both butter (1.16 mmol/L) and coco-
nut oil (1.21 mmol/L) significantly raised HDL-C com-
pared with safflower oil (1.06 mmol/L) (P<0.01), with
no significant difference between coconut oil and but-
ter. Plasma triglyceride levels were reduced from
1.98 mmol/L in all 3 test groups, with the coconut oil
group showing the lowest concentration (1.61 mmol/L)
compared with the safflower oil group (1.77 mmol/L)
and the butter group (1.86 mmol/L). However, this ef-
fect was not statistically significant between treatments
(P¼0.18). The results of both these studies by Cox
et al.
31,32
suggest that coconut consumption has a detri-
mental effect on blood lipids and lipoproteins compared
with safflower oil, a cis unsaturated fat. The results are
less clear when comparing coconut with butter. One
study reported significantly lower total cholesterol and
LDL-C following coconut oil consumption in compari-
son with butter consumption,
31
whereas the other study
reported no difference.
32
The randomized crossover study by Voon et al.,
38
conducted in 45 healthy young Malaysian adults, exam-
ined a range of biomarkers that included homocysteine,
C-reactive protein, and fasting and postprandial lipid
levels after consumption of meals with different fat com-
positions over a 5-week period. The diets were high in
Table 3 Continued
Reference Study design
(country)
Participants Intervention Comparator Outcome (mmol/L, except where specified)
TG: coconut oil (0.90 60.39) >palm oil (0.85 60.31) >ol-
ive oil (0.84 60.37) (N/S)
ApoA-I (mmol/L): olive oil (46.09 69.03) <palm oil
(46.95 68.68) <coconut oil (47.64 69.71) (N/S)
ApoB (mmol/L): palm oil (2.79 60.69) ¼coconut oil
(2.79 60.88) >olive oil (2.67 60.88) (N/S)
Lp(a): olive oil (0.95 61.79) >palm oil (0.93 61.86) >co-
conut oil (0.92 61.91) (N/S)
tHcy (mmol/L): coconut oil (9.13 63.17) >palm oil
(8.88 63.05) >olive oil (8.76 62.96) (N/S)
No statistically significant differences in inflammatory
markers
Abbreviations: ApoA-1, apolipoprotein A-1; ApoA-II, apolipoprotein A-II; ApoB, apolipoprotein B; ApoE, apolipoprotein E; BMI, body mass index; CETA, cholesteryl ester transfer activity; F, fe-
males; HDL, high-density lipoprotein cholesterol; IDL, intermediate-density lipoprotein cholesterol; LDL, low-density lipoprotein cholesterol; Lp(a), lipoprotein a; M, males; N/S, not statistically
significant; PUFA, polyunsaturated fatty acids; SFA, saturated fatty acids; TC, total cholesterol; TG, triglycerides; tHcy, total homocysteine; VLDL, very low-density lipoprotein cholesterol.
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protein (20% of energy), with the test fats (palm olein,
coconut oil, and virgin olive oil) providing 67% of total
fat, which in turn was 30% of energy. The levels of ho-
mocysteine and other inflammatory biomarkers such as
C-reactive protein were not significantly different be-
tween the 3 treatments. Lipid profiles showed that the
coconut oil group had significantly higher total choles-
terol (4.95 mmol/L vs 4.65 mmol/L) and LDL-C
(3.30 mmol/L vs 3.06 mmol/L) levels compared with the
olive oil group (all P<0.05). Although HDL-C concen-
trations were significantly higher in the coconut oil
group compared with olive oil group (1.37 mmol/L vs
1.28 mmol/L, P<0.05), ratios of total cholesterol to
HDL-C were not significantly different between the 3
test diets. Other outcomes did not differ significantly be-
tween the palm olein treatment and the other 2 treat-
ments. Similar to the studies above, coconut oil
consumption was associated with a more atherogenic
profile in terms of total and LDL cholesterol. It is impor-
tant to note, however, that there was no difference in the
ratio of total cholesterol to HDL-C, which is a strong
predictor of CVD risk.
Reiser et al.
37
conducted a relatively small random-
ized crossover trial in medical students that assessed the
effects of coconut oil, safflower oil, and beef fat on fast-
ing plasma lipid and lipoproteins. Nineteen male partic-
ipants consumed 2 or 3 of the diets for 5 weeks each,
eating their normal diet in between the test diets. The
test fat provided 60% of energy from fat, with total fats
providing 35% of energy. In comparison with the saf-
flower oil diet (total cholesterol, 3.65 mmol/L; HDL-C,
1.03 mmol/L; LDL-C, 2.33 mmol/L), the coconut oil
diet resulted in significantly higher concentrations of
total cholesterol (4.34 mmol/L), HDL-C (1.19 mmol/L),
and LDL-C (2.84 mmol/L), with no significant differ-
ence in triglycerides (0.81 mmol/L vs 0.88 mmol/L). In
comparison with the beef fat diet (total cholesterol,
4.01 mmol/L; HDL-C, 1.03 mmol/L; LDL-C, 0.99 mmol/
L), the coconut oil diet resulted in significantly higher
total cholesterol and HDL-C and lower triglycerides,
with no significant difference in LDL-C (2.53 mmol/L
vs 2.84 mmol/L). Although this study sample is rela-
tively small, the results are consistent with other re-
search in terms of reporting significant increases in
total and LDL cholesterol among those consuming the
coconut oil diet.
Ng et al.
36
conducted a 3-part sequential feeding
study in 83 normocholesterolemic Malaysian partici-
pants. Participants were randomized to 1 of 3 groups
and received a sequence of (1) coconut oil/palm oil/co-
conut oil; (2) coconut oil/corn oil/coconut oil; or (3)
coconut oil for all three 5-week dietary periods. Fat as
a percentage of energy ranged from 27% to 31%, with
the study oils suppling approximately 75% of total fat.
Following coconut oil feeding, subsequent feeding of
palm oil or corn oil resulted in reductions in total cho-
lesterol (19% and 36%, respectively), LDL-C (20% and
42%, respectively), and HDL-C (20% and 26%, respec-
tively), all P<0.01. Neither the ratio of LDL-C to
HDL-C nor triglyceride levels were significantly differ-
ent between the coconut oil and palm oil diets, but
both were significantly lower after the corn oil diet
compared with the coconut oil diet (both P<0.01).
Compared with baseline, coconut oil increased total
cholesterol concentrations by more than 10% in all
groups. It should be noted that, although this study
had 83 participants, each completed only 1 of 3 se-
quences, meaning the number in whom the different
oils were compared ranged from 26 to 27 participants.
In addition, the participants did not receive the differ-
ent oils in random order. Overall, these results indicate
a detrimental effect on both total and LDL cholesterol.
In addition, although HDL-C was higher after the co-
conut oil diet, the proportionally greater increase in
LDL-C resulted in a significantly higher ratio of LDL-
C to HDL-C compared with the ratio in participants
who consumed the corn oil diet. Collectively, these
findings indicate that coconut oil consumption results
in an atherogenic profile when compared with corn oil
consumption. Further, coconut oil offered no advan-
tage over palm oil.
A randomized community-based feeding experi-
ment with 60 Sri Lankans over a 62-week period as-
sessed the effects of lowering coconut and saturated fat
intake compared with partial replacement of saturated
fat from coconut with polyunsaturated fat from soya-
bean and sesame oil.
35
Both intervention diets were low
in fat (20% total energy vs 24% total energy). The use of
field workers who made regular visits to the households
facilitated the collection of detailed dietary information
and supervision of the intervention phases. The results
showed that reducing the saturated fat intake or replac-
ing a portion of the saturated fat in the diet with unsat-
urated fat resulted in improved serum lipoprotein
profiles compared with baseline. Both groups showed a
24% to 27% decrease in the ratio of total cholesterol to
HDL-C at 12 months compared with baseline (both
groups, P<0.002). The difference between groups was
not significant. In addition, there were significant re-
ductions in LDL-C and increases in HDL-C in both
groups, with a significantly greater reduction in LDL-C
in the soyabean and sesame oil group. The only adverse
effect was a small but significant increase (8.2%) in tri-
glycerides in the group supplemented with soyabean
and sesame oil, but in this group some of the total fat
was replaced by carbohydrate. A limitation of this study
is the lack of a control group whose intake of coconut
oil was not modified.
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An earlier sequential feeding study by Mendis and
Kumarasunderam
34
assessed the effects of coconut oil
consumption vs soyabean oil consumption over two 8-
week periods, with a 3-week washout period, on 25
healthy males. Thirty percent of total energy was con-
sumed as fat, the test fats constituting 70% of fat intake.
In contrast to the later findings of Mendis et al.,
35
this
study showed a beneficial effect of soyabean oil on tri-
glyceride levels (1.42–1.06 mmol/L) compared with base-
line (P<0.01). Additionally, the soyabean intervention
significantly reduced total cholesterol (4.46–3.68mmol/
L) and LDL-C (2.95–2.27 mmol/L) (both P<0.01) and
lowered HDL-C from 1.10 to 0.94 mmol/L (P<0.05).
The coconut oil diet resulted in a return to levels of se-
rum lipids that were not significantly different from
baseline levels. Only total cholesterol was reported as be-
ing statistically significantly different between the coco-
nut oil and soyabean oil interventions. Interestingly,
although LDL-C was lower with soyabean oil than with
coconut oil (2.27 60.36 vs 2.84 60.3 mmol/L), this dif-
ference was not statistically significant, a finding unique
to this study.
Fisher et al.
33
compared corn oil with coconut oil
in mixed diets in a small number (9 healthy males) of
participants for 9 days. They measured changes in blood
lipids and lipoproteins and examined the effects of indi-
vidual variations in lipoprotein metabolism on the end
results. Coconut oil was found to have adverse effects,
shifting the distribution of apolipoprotein E toward
very low-density lipoprotein (VLDL) cholesterol frac-
tions. Compared with the corn oil diet, the coconut oil
diet was associated with significant increases in total
cholesterol, VLDL cholesterol, intermediate-density li-
poprotein cholesterol þLDL-C, HDL-C, total triglycer-
ides, and VLDL triglycerides as well as significant
increases in the apolipoprotein E content in intermedi-
ate-density lipoprotein cholesterol þLDL-C (all
P<0.01). An important limitation of this study is the
small sample size, which hampers interpretation of the
results.
DISCUSSION
This review identified a limited amount of human re-
search on which to assess the merits of coconut oil or
coconut products in relation to cardiovascular health.
Much of the research has important limitations that
warrant caution when interpreting results, such as small
sample size, biased samples, inadequate dietary assess-
ment, and a strong likelihood of confounding.
There is no robust evidence on disease outcomes,
and most of the evidence is related to lipid profiles. In
comparison with other fat sources, coconut oil did not
raise total or LDL cholesterol to the same extent as
butter in one of the studies by Cox et al.,
31
but it did in-
crease both measures to a greater extent than did cis un-
saturated vegetable oils.
In total, 7 intervention studies directly compared
coconut oil with oils containing cis unsaturated fat.
31–
34,36–38
The coconut oil interventions resulted in signifi-
cantly higher total cholesterol in all 7 trials, with signifi-
cantly higher LDL-C in 6 trials
31–33,36–38
and with no
significant difference in 1 trial.
34
High-density lipopro-
tein cholesterol was significantly higher after the coco-
nut oil interventions in 5 of the trials,
32,33,36–38
with no
significant difference observed in the remaining 2 tri-
als.
31,34
Ratios of total cholesterol to HDL-C or of LDL-
C to HDL-C were examined in only 2 of these studies.
One study reported a significantly higher LDL-C:HDL-
C ratio after a coconut oil diet compared with a corn oil
diet,
36
while one reported a significantly lower ratio of
total cholesterol to HDL-C following a coconut oil diet
compared with an olive oil diet.
38
Five studies reported
no significant difference in triglyceride concentra-
tions,
31,32,34,37,38
while 2 studies reported lower triglyc-
eride concentrations following a corn oil diet compared
with a coconut oil diet.
33,36
While the inconsistent findings on the effects of co-
conut oil on HDL-C, on the ratio of total cholesterol to
HDL-C, and on the ratio of LDL-C to HDL-C make it
difficult to predict the effects of coconut oil on CVD
risk, it should be noted that the significantly lower
LDL-C concentrations observed among participants
who received cis unsaturated fat treatments compared
with participants who received coconut oil diets ranged
from 0.24 mmol/L to 1.03 mmol/L. It has been reported
that every 1-mmol/L reduction in LDL-C is associated
with a corresponding average 22% reduction in CVD
mortality and morbidity.
39
In addition, it has been cal-
culated that, in New Zealand, a reduction in the inci-
dence of ischemic heart disease in the order of 10%
among the population can be achieved by substituting
5% of the daily energy (10–14 g) from saturated fat with
polyunsaturated fat.
40
On the basis of these predictions,
it appears that consuming cis unsaturated fat in place of
coconut oil is likely to result in substantial reductions in
the risk of CVD.
Not all saturated fatty acids produce the same cho-
lesterol-raising effects. Differences in the effects have
been attributed to a combination of variations in the
structural shape, the melting point, and the water solu-
bility of the fatty acids.
11
Fatty acids may affect the me-
tabolism of fat in the liver as well as subsequent levels of
cholesterol and lipoproteins in several ways, depending
on how the fatty acid is presented to the liver, i.e., via
the portal vein or via chylomicrons,
11
or on the stereo-
specific position of the fatty acid in the triglyceride
molecule.
41
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Ninety-five percent of medium-chain triglycerides
are absorbed through the portal vein. The subsequent
rise in cholesterol was reported to be 50% of that from
palmitic acid.
42
In contrast, less than 5% of palmitic
acid is absorbed via the portal vein. Studies have re-
ported that 25% to 30% of lauric acid is absorbed
through the portal vein.
11
Lauric acid, because of its
shorter chain length and lower melting point, may im-
part less rigidity to triglyceride and phospholipid mole-
cules than does palmitic acid and thus may have
different effects on hepatic cholesterol and/or lipid me-
tabolism. If only 70% of the lauric acid is absorbed via
chylomicrons, then this may explain why LDL-C con-
centrations were lower after coconut oil consumption
than after butterfat consumption in one of the studies
by Cox et al.
31
However, when the data from the 5 trials that di-
rectly compared coconut oil with another saturated fat
are examined collectively, the results are largely incon-
sistent.
31,32,36–38
The comparators in these interventions
included butter in 2 trials,
31,32
beef fat in 1 trial,
37
and
palm oil in the remaining 2 trials.
36,38
There was a sig-
nificant reduction in total and LDL cholesterol in the
coconut oil arm compared with the butter arm in one
study,
31
but not in another.
32
One study found no dif-
ference between palm oil and coconut oil with regard to
changes in total and LDL cholesterol,
38
while the other
reported significantly higher concentrations following
the coconut oil diet.
36
Compared with the beef fat arm,
total cholesterol, but not LDL-C, was significantly
higher in the coconut oil arm.
37
Concentrations of
HDL-C were not different between coconut oil and but-
ter treatments
31,32
but were significantly higher in the
coconut oil arm of a study that used beef fat as the com-
parator.
37
Conversely, HDL-C was higher in the coco-
nut oil arm than in the palm oil in one study,
36
but not
the other.
38
Triglyceride concentrations were signifi-
cantly lower in one of the studies in which the compari-
son was butter,
31
but not in the other.
32
Triglycerides
were also significantly lower when coconut oil was com-
pared with beef fat,
37
but they did not differ when coco-
nut oil was compared with palm oil.
36,38
Only one
study
36
measured the LDL-C:HDL-C ratio and reported
a lower ratio following the palm oil diet compared with
the coconut oil diet. The total cholesterol to HDL-C ra-
tio was measured only by Voon et al.,
38
who reported
no difference between the coconut oil diet and the palm
oil diet. Collectively, these results do not provide evi-
dence that coconut oil acts consistently different from
other saturated fats in terms of its effects on blood lipids
and lipoproteins.
In summary, this review found no evidence that co-
conut oil should be viewed differently from other sour-
ces of dietary saturated fat with regard to dietary
recommendations. This is in line with recommenda-
tions from the American Heart Association and the US
Department of Agriculture’s Dietary Guidelines for
Americans, 2010
43
, which suggest that coconut oil is not
preferable to other saturated fats. Guidelines from both
agencies continue to recommend that dietary saturated
fat be limited to 7% to 10% of calories because it can in-
crease the risk for heart disease.
It has been hypothesized that the more favorable
lipid profiles and lower mortality rates observed in coco-
nut-consuming populations are due to the foods that
constitute the rest of their traditional diets.
17
The major-
ity of the Pacific Island populations, such as those from
the islands of Tokelau and Pukapuka, traditionally ate no
processed foods and consumed a diet high in fruit and
vegetables, with the main protein source being fish. The
original participants of the Kitava study had an active
lifestyle without major influences from a Western diet.
This is in contrast to the consumption of coconut oil in a
typical Western diet, which contains more processed
foods, less fish, less fruit and vegetables, and more satu-
rated fat than recommended in dietary guidelines.
44
Studies suggest that the consumption of coconut
products that contain fiber, such as coconut flesh and
coconut flour,
45
within a traditional dietary pattern that
includes sufficient polyunsaturated fats (omega-3) in
the absence of excessive calories from refined carbohy-
drates does not pose a risk for heart disease. In contrast,
the excessive use of coconut oil as the major lipid in the
typical Western diet produces effects similar to those of
other saturated fats. Despite claims that coconut oil
may reduce cardiovascular risk factors, this review
found no evidence indicating that coconut oil is prefer-
able to other unsaturated plant oils.
This review included studies published up to the
end of 2013. The search was subsequently updated to
include studies published up to November 2015.
Although several studies were published during this pe-
riod, most suffer fundamental flaws, and thus only one
study met the inclusion criteria.
46
In a further analysis
of their previously reported study, Voon et al.
38
used a
randomized crossover study to compare the effects of
virgin olive oil, palm olein, and coconut oil on cell ad-
hesion molecules and thrombogenicity indices in 45
healthy adults in Malaysia. As mentioned previously,
the diets contained 30% of energy from fat, and the
study oils supplied two-thirds of total fat. There were
no significant differences between the 3 oils for throm-
bogenicity indices, but olive oil significantly lowered
proinflammatory leukotriene B
4
compared with both
palm olein and coconut oil. In addition, the plasma
antiaggregatory 6-keto-prostaglandin F
1a
was signifi-
cantly lower after the olive oil treatment compared with
the palm olein treatment.
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This additional study also fails to provide any evidence
that consumption of coconut oil results in benefits prefera-
ble to those seen with plant cis unsaturated oils, and thus
the conclusion of this review remains unchanged.
CONCLUSION
In summary, although evidence of an association be-
tween coconut consumption and risk factors for heart
disease is mostly of very poor quality, it suggests that
coconut oil, when compared with cis unsaturated plant
oils, raises total cholesterol, HDL-C, and LDL-C, al-
though not as much as butter does. The impact of coco-
nut oil consumption on the ratio of total cholesterol to
HDL-C was often not reported. No convincing evidence
that consumption of coconut oil, as opposed to con-
sumption of unsaturated oils, led to improved lipid pro-
files and a decreased risk of CVD was discovered
during the literature search. Overall, the weight of the
evidence to date suggests that replacing coconut oil
with cis unsaturated fats would reduce CVD risk.
Therefore, this review does not support popular claims
purporting that coconut oil is a healthy oil in terms of
reducing the risk of CVD. There was no evidence that
coconut oil acted consistently different from other satu-
rated fats in terms of its effects on blood lipids and lipo-
proteins. Given the limited number of intervention
studies in this area, along with the methodological flaws
evident in existing studies, further well-designed ran-
domized trials that include appropriate controls, are ad-
equately powered, and examine a range of CVD risk
factors are required.
Acknowledgments
Funding. Funding for this review was provided by the
National Heart Foundation of New Zealand (NHFNZ).
Nutritionists from the NHFNZ assisted with both the
initial literature review and the production of an inter-
nal report for their website but played no role in the
writing of this paper.
Declaration of interest. The authors have no relevant
interests to declare.
REFERENCES
1. Eyres L. Handbook of Australasian Edible Oils. Auckland: Oils and Fats Specialist
Group of the New Zealand Institute of Chemistry; 2007.
2. Marina A, Che-Man Y, Nazimah S, et al. Chemical properties of virgin coconut oil. J
Am Oil Chem Soc. 2009;86:301–307.
3. Gunstone F. Lauric oils.Lipid Technol. 2010;22:168. doi:10.1002/lite.201000035.
4. Srivastava S, Singh M, George J, et al. Genotoxic and carcinogenic risks associated
with the dietary consumption of repeatedly heated coconut oil. Br J Nutr.
2010;104:1343–1352.
5. Sivakumaran S, Huffman L. The Concise New Zealand Food Composition Tables.
11th ed. Palmerston North, New Zealand: New Zealand Institute for Plant and
Food Research Limited and Ministry of Health NewZealand; 2014.
6. US Department of Agriculture, Agriculture Research Service. USDA National
Nutrient Database for Standard Reference. Nutrient Data Laboratory website;
2012. http://www.nal.usda.gov/fnic/foodcomp/search/. Accessed March 23, 2012.
7. Yong JW, Ge L, Ng YF, et al. The chemical composition and biological properties
of coconut (Cocos nuciferaL.) water. Molecules. 2009;14:5144–51 64.
8. Bach A, Babayan V. Medium-chain triglycerides: an update. Am J Clin Nutr.
1982;36:950–962.
9. Eyres L. Analysis of edibleoils and fats. Chem New Zeal. 1979;43:237–239.
10. Williams M, Tamai K, Hincenbergs T, et al. Hydrogenated coconut oil and tissue fatty
acids in EFA-depleted and EFA-supplemented rats. JNutr. 1972;102:847–856.
11. Denke MA, Grundy SM. Comparison of effects of lauric acid and palmitic acid on
plasma lipids and lipoproteins. Am J Clin Nutr. 1992;56:895–898.
12. Swift LL, Hill JO, Peters JC, et al. Medium-chain fattyacids: evidence for incorpora-
tion into chylomicron triglycerides in humans. Am J Clin Nut r. 1990;52 :834–836.
13. Marten B, Pfeuffer M, Schrezenmeir J. Medium-chain triglycerides. Int Dairy J.
2006;16:1374–1382.
14. Timmermann F. Oils and Fats in the Nineties. Lystrup, Denmark: International Food
Science Centre; 1992.
15. Stanhope JM, Sampson VM, Prior IA. The Tokelau Island Migrant Study: serum
lipid concentration in two environments.J ChronicDis. 1981;34:45–55.
16. Parry J. Pacific Islanders pay heavy price for abandoning traditional diet. Bull
World Health Organ. 2010;88:484–485.
17. DiBello JR, McGarvey ST, Kraft P, et al. Dietary patterns are associated with meta-
bolic syndrome in adult Samoans. JNutr. 2009;139:1933–1943.
18. Kumar PD. The role of coconut and coconut oil in coronary heart disease in Kerala,
South India.Trop Doc. 1997;27:215 –217.
19. Lindeberg S, Berntorp E, Nilsson-Ehle P, et al. Age relations of cardiovascular risk
factors in a traditional Melanesian society: the Kitava Study. Am J Clin Nutr.
1997;66:845–852.
20. Prior IA, Davidson F, Salmond CE, et al. Cholesterol, coconuts, and diet on
Polynesian atolls: a natural experiment: the Pukapuka and Tokelau island studies.
Am J Clin Nutr. 1981;34:1552–15 61.
21. Abeywardena M. Dietary fats, carbohydrates and vascular disease: Sri Lankan per-
spectives.Atherosclerosis. 2003;171:157–161.
22. Dayrit C. Coconut oil: atherogenic or not? Philipp J Cardiol.2003;31:97–104.
23. Lindeberg S, Lundh B. Apparent absence of stroke and ischaemic heart disease in
a traditional Melanesian island: a clinical study in Kitava. J Intern Med.
1993;233:269–275.
24. Lindeberg S, Nilsson-Ehle P, Vessby B. Lipoprotein composition and serum choles-
terol ester fatty acids in nonwesternized Melanesians. Lipids. 1996;31:1 53–158.
25. Feranil AB, Duazo PL, Kuzawa CW, et al. Coconut oil is associated with a beneficial
lipid profile in pre-menopausal women in the Philippines. Asia Pac J Clin Nutr.
2011;20:190–195.
26. Sabitha P, Vaidyanathan K, Vasudevan DM, et al. Comparison of lipid profile and
antioxidant enzymes among south Indian men consuming coconut oil and sun-
flower oil. Indian J Clin Biochem. 2009;24:76–81.
27. Njelekela M, Kuga S, Nara Y, et al. Prevalence of obesity and dyslipidemia in mid-
dle-aged men and women in Tanzania, Africa: relationship with resting energy ex-
penditure and dietary factors. J Nutr Sci Vitaminol. 2002;48:352–358.
28. Njelekela M, Sato T, Nara Y, et al. Nutritional variation and cardiovascular risk fac-
tors in Tanzania – rural-urbandifference. S Afr Med J. 2003;93:295–299.
29. Lipoeto NI, Agus Z, Oenzil F, et al.Dietary intake and the risk of coronary heart dis-
ease among the coconut-consuming Minangkabau in West Sumatra, Indonesia.
Asia Pac J Clin Nutr. 2004;13 :377–384.
30. Beegom R, Singh RB. Association of higher saturated fat intake with higher risk of
hypertension in an urban population of Trivandrum in South India. Int J Cardiol.
1997;58:63–70.
31. Cox C, Mann J, Sutherland W, et al. Effects of coconut oil, butter, and safflower oil
on lipids and lipoproteins in persons with moderately elevated cholesterol levels.
JLipidRes. 1995;36:1787–1795.
32. Cox C, Sutherland W, Mann J, et al. Effects of dietary coconut oil, butter and saf-
flower oil on plasma lipids, lipoproteins and lathosterol levels. Eur J Clin Nutr.
1998;52:650–654.
33. Fisher EA, Blum CB, Zannis VI, et al. Independent effects of dietary saturated fat
and cholesterol on plasma lipids, lipoproteins, and apolipoprotein E. J Lipid Res.
1983;24:1039–1048.
34. Mendis S, Kumarasunderam R. The effectof daily consumption of coconut fat and
soya-bean fat on plasma lipids and lipoproteins of young normolipidaemic men.
Br J Nutr. 1990;63 :547–552.
35. Mendis S, Samarajeewa U, Thattil RO. Coconut fat and serum lipoproteins: effects
of partial replacement withunsaturated fats. Br J Nutr. 2001;85:583–589.
36. Ng TK, Hassan K, Lim JB, et al. Nonhypercholesterolemic effects of a palm-oil diet
in Malaysianvolunteers. Am J Clin Nutr. 1991;53(4 suppl):1015S–1020S.
37. Reiser R, Probstfield JL, Silvers A, et al. Plasma lipid and lipoprotein response
of humans to beef fat, coconut oil and safflower oil. Am J Clin Nutr.1985;42:
190–197.
Nutrition Reviews
V
R
Vol. 0(0):1–14 13
by guest on March 8, 2016http://nutritionreviews.oxfordjournals.org/Downloaded from
38. Voon PT, Ng TK, Lee VK, et al. Diets high inpalmitic acid (16:0), lauric and myristic
acids (12:0 þ14:0), or oleic acid (18:1) do not alter postprandial or fasting plasma
homocysteine and inflammatory markers in healthy Malaysian adults. Am J Clin
Nutr. 2011;94:145 1–1457.
39. Cholesterol Treatment Trialists Collaboration, Baigent C, Blackwell L, et al. Efficacy
and safety of more intensive lowering of LDL cholesterol: a meta-analysis of data
from 170,000 participants in 26 randomised trials. Lancet. 2010;376:1670–1681.
40. Foster RH, Wilson N. Review of the evidence for the potential impact and feasibil-
ity of substituting saturated fat in the New Zealand diet. Aust N Z J Public Health.
2013;37:329–336.
41. Decker EA. The role of stereospecific saturated fatty acid positions on lipid nutri-
tion. Nutr Rev. 1996;54(4 pt 1):108–110.
42. Cater NB, Heller HJ, Denke MA. Comparison of the effects of medium-chain triacyl-
glycerols, palm oil, and high oleic acid sunflower oil on plasma triacylglycerol fatty
acids and lipid and lipoprotein concentrations in humans. Am J Clin Nutr.
1997;65:41–45.
43. US Department of Agriculture and US Department of Health and Human Services.
Dietary Guidelines for Americans, 2010. Washington, DC: US Government Printing
Office; 2010.
44. University of Otago and Ministry of Health. A Focus on Nutrition: Key Findings of
the 2008/09 New Zealand Adult Nutrition Survey. Wellington, New Zealand:
Ministry of Health New Zealand;2011.
45. Trinidad TP, Loyola AS, Mallillin AC, et al. The cholesterol-lowering effect of coco-
nut flakes in humans with moderately raised serum cholesterol. J Med Food.
2004;7:136–140.
46. Voon PT, Ng TKW, Lee VKM, et al. Virgin olive oil, palm olein and coconut oil diets
do not raise cell adhesion molecules and thrombogenicity indices in healthy
Malaysianadults. Eur J Clin Nutr. 2015;69:712–716.
14 Nutrition Reviews
V
R
Vol. 0(0):1–14
by guest on March 8, 2016http://nutritionreviews.oxfordjournals.org/Downloaded from
