A New Look At Coconut Oil
by Mary G. Enig, Ph.D.
Health and Nutritional Benefits from Coconut Oil:
An
Important Functional Food
for the 21st Century
Presented at the AVOC Lauric Oils Symposium, Ho Chi Min City,
Vietnam, 25 April 1996
Abstract
Coconut
oil has a unique role in the diet as an important physiologically functional
food. The health and nutritional benefits that can be derived from consuming
coconut oil have been recognized in many parts of the world for centuries. Although
the advantage of regular consumption of coconut oil has been underappreciated
by the consumer and producer alike for the recent two or three decades, its
unique benefits should be compelling for the health minded consumer of today.
A review of the diet/heart disease literature relevant to coconut oil clearly
indicates that coconut oil is at worst neutral with respect to atherogenicity
of fats and oils and, in fact, is likely to be a beneficial oil for prevention
and treatment of some heart disease. Additionally, coconut oil provides a source
of antimicrobial lipid for individuals with compromised immune systems and is
a nonpromoting fat with respect to chemical carcinogenesis.
I. INTRODUCTION
Mr. Chairman and members of the ASEAN Vegetable Oils Club, I would like to
thank you for inviting me to participate in this Lauric Oils Symposium. I am
pleased to have the opportunity to review with you some information that I hope
will help redress some of the anti-tropical oils rhetoric that has been so
troublesome to your industry.
I will be covering two important areas in my presentation. In the first part,
I would like to review the history of the major health challenge facing coconut
oil today. This challenge is based on a supposed negative role played by
saturated fat in heart disease. I hope to dispel any acceptance of this notion
with the information I will present to you today. I will show you how both
animal studies and human studies have exonerated coconut oil of causing the
problem.
In the second part of my talk I will suggest some new directions where
important positive health benefits are seen for coconut oil. These benefits stem
from coconut oil's use as a food with major antimicrobial and anticancer
benefits. I will present to you some of the rationale for this effect and some
of the supporting literature.
The health and nutritional benefits derived from coconut oil are unique and
compelling. Although the baker and food processor have recognized the functional
advantages of coconut oil in their industries, over most competing oils, for
many years, I believe these benefits are underappreciated today by both the
producer and the consumer. It is time to educate and reeducate all those who
harbor this misinformation.
Historically, coconuts and their extracted oil have served man as important
foods for thousands of years. The use of coconut oil as a shortening was
advertised in the United States in popular cookbooks at the end of the 19th
century. Both the health-promoting attributes of coconut oil and those
functional properties useful to the homemaker were recognized 100 years ago.
These same attributes, in addition to some newly discovered ones, should be of
great interest to both the producing countries as well as the consuming
countries.
II. ORIGINS OF THE DIET/HEART HYPOTHESIS
Although popular literature of epidemiological studies usually attribute an
increased risk of coronary heart disease (CHD) to elevated levels of serum
cholesterol, which in turn are thought to derive from a dietary intake of
saturated fats and cholesterol. But, saturated fats may be considered a major
culprit for CHD only if the links between serum cholesterol and CHD, and between
saturated fat and serum cholesterol are each firmly established. Decades of
large-scale tests and conclusions therefrom have purported to establish the
first link. In fact, this relationship has reached the level of dogma. Through
the years metabolic ward and animal studies have claimed that dietary saturated
fats increase serum cholesterol levels, thereby supposedly establishing the
second link. But the scientific basis for these relationships has now been
challenged as resulting from large-scale misinterpretation and misrepresentation
of the data. (Enig 1991, Mann 1991, Smith 1991, Ravnskov 1995)
Ancel Keys is largely responsible for starting the anti-saturated fat agenda
in the United States. From 1953 to 1957 Keys made a series of statements
regarding the atherogenicity of fats. These pronouncements were:
"All fats raise serum cholesterol; Nearly half of total fat comes from
vegetable fats and oils; No difference between animal and vegetable fats in
effect on CHD (1953); Type of fat makes no difference; Need to reduce
margarine and shortening (1956); All fats are comparable; Saturated fats raise
and polyunsaturated fats lower serum cholesterol; Hydrogenated vegetable fats
are the problem; Animal fats are the problem (1957-1959)."
As can be seen, his findings were inconsistent.
What was the role of the edible oil industry in promoting the diet/heart
hypothesis?
It is important to realize that at that time (1960s) the edible
oil industry in the United States seized the opportunity to promote its
polyunsaturates. The industry did this by developing a health issue focusing on
Key's anti-saturated fat bias. With the help of the edible oil industry lobbying
in the United States, federal government dietary goals and guidelines were
adopted incorporating this mistaken idea that consumption of saturated fat was
causing heart disease. This anti-saturated fat issue became the agenda of
government and private agencies in the US and to an extent in other parts of the
world. This is the agenda that has had such a devastating effect on the coconut
industry for the past decade. Throughout the 1960s, the 1970s, the 1980s, and
the 1990s, the anti-saturated fat rhetoric increased in intensity.
What are some of the contradictions to the hypothesis blaming saturated fat?
Recently, an editorial by Harvard's Walter Willett, M.D. in the American
Journal of Public Health (1990) acknowledged that even though
"the focus of dietary recommendations is usually a reduction of saturated
fat intake, no relation between saturated fat intake and risk of CHD was
observed in the most informative prospective study to date."
Another editorial, this time by Framingham's William P. Castelli in the
Archives of Internal Medicine (1992), declared for the record that
"...in Framingham, Mass, the more saturated fat one ate, the more
cholesterol one ate, the more calories one ate, the lower the person's
serum cholesterol... the opposite of what the equations provided by Hegsted at
al (1965) and Keys et al (1957) would predict..."
Castelli further admitted that
"...In Framingham, for example, we found that the people who ate the most
cholesterol, ate the most saturated fat, ate the most calories, weighed the
least, and were the most physically active."
III. COCONUT OIL AND THE DIET/HEART HYPOTHESIS
For the past several decades you have heard about animal and human studies
feeding coconut oil that purportedly showed increased indices for cardiovascular
risk. Blackburn et al (1988) have reviewed the published literature of coconut
oil's effect on serum cholesterol and atherogenesis and have concluded that when
...[coconut oil is] fed physiologically with other fats or adequately
supplemented with linoleic acid, coconut oil is a neutral fat in terms of
atherogenicity. After reviewing this same literature, Kurup and Rajmohan
(1995) conducted a study on 64 volunteers and found ...no statistically
significant alteration in the serum total cholesterol, HDL cholesterol, LDL
cholesterol, HDL cholesterol/total cholesterol ratio and LDL cholesterol/HDL
cholesterol ratio of triglycerides from the baseline values... A beneficial
effect of adding the coconut kernel to the diet was noted by these researchers.
How did coconut oil get such a negative reputation?
The question then is, how did coconut oil get such a negative reputation? The
answer quite simply is, initially, the significance of those changes that
occurred during animal feeding studies were misunderstood. The wrong
interpretation was then repeated until ultimately the misinformation and
disinformation took on a life of its own.
The problems for coconut oil started four decades ago when researchers fed
animals hydrogenated coconut oil that was purposefully altered to make it
completely devoid of any essential fatty acids. The hydrogenated coconut oil was
selected instead of hydrogenated cottonseed, corn or soybean oil because it was
a soft enough fat for blending into diets due to the presence of the lower
melting medium chain saturated fatty acids. The same functionality could not be
obtained from the cottonseed, corn or soybean oils if they were made totally
saturated, since all their fatty acids were long chain and high melting and
could not be easily blended nor were they as readily digestible.
The animals fed the hydrogenated coconut oil (as the only fat source)
naturally became essential fatty acid deficient; their serum cholesterol levels
increased. Diets that cause an essential fatty acid deficiency always produce an
increase in serum cholesterol levels as well as an increase in the
atherosclerotic indices. The same effect has also been seen when other essential
fatty acid deficient, highly hydrogenated oils such as cottonseed, soybean, or
corn oils have been fed; so it is clearly a function of the hydrogenated
product, either because the oil is essential fatty acid (EFA) deficient or
because of trans fatty acids (TFA).
What about the studies where animals were fed with unprocessed coconut oil?
Hostmark et al (1980) compared the effects of diets containing 10% coconut
fat and 10% sunflower oil on lipoprotein distribution in male Wistar rats.
Coconut oil feeding produced significantly lower levels (p=<0.05) of pre-beta
lipoproteins (VLDL) and significantly higher (p=<0.01) alpha-lipoproteins (HDL)
relative to sunflower oil feeding.
Awad (1981) compared the effects of diets containing 14% coconut oil, 14%
safflower oil or a 5% "control" (mostly soybean) oil on accumulation of
cholesterol in tissues in male Wistar rats. The synthetic diets had 2% added
corn oil with a total fat of 16% Total tissue cholesterol accumulation for
animals on the safflower diet was six times greater than for animals fed the
coconut oil, and twice that of the animals fed the control oil.
A conclusion that can be drawn from some of this animal research is that
feeding hydrogenated coconut oil devoid of essential fatty acids (EFA) in a diet
otherwise devoid of EFA leads to EFA deficiency and potentiates the formation of
atherosclerosis markers. It is of note that animals fed regular coconut oil have
less cholesterol deposited in their livers and other parts of their bodies.
What about the studies where coconut oil is part of the normal diet of human
beings?
Kaunitz and Dayrit (1992) have reviewed some of the epidemiological and
experimental data regarding coconut-eating groups and noted that the
available population studies show that dietary coconut oil does not lead to high
serum cholesterol nor to high coronary heart disease mortality or morbidity.
They noted that in 1989 Mendis et al reported undesirable lipid changes when
young adult Sri Lankan males were changed from their normal diets by the
substitution of corn oil for their customary coconut oil. Although the total
serum cholesterol decreased 18.7% from 179.6 to 146.0 mg/dl and the LDL
cholesterol decreased 23.8% from 131.6 to 100.3 mg/dl, the HDL cholesterol
decreased 41.4% from 43.4 to 25.4 mg/dl (putting the HDL values below the
acceptable lower limit) and the LDL/HDL ratio increased 30% from 3.0 to 3.9.
These latter two changes would be considered quite undesirable. As noted above,
Kurup and Rajmohan (1995) studied the addition of coconut oil alone to
previously mixed fat diets and report no significant difference.
Previously, Prior et al (1981) had shown that islanders with high intake of
coconut oil showed no evidence of the high saturated fat intake having a
harmful effect in these populations. When these groups migrated to New
Zealand however, and lowered their intake of coconut oil, their total
cholesterol and LDL cholesterol increased, and their HDL cholesterol decreased.
What about the studies where coconut oil was deliberately fed to human
beings?
Some of the studies reported thirty and more years ago should have cleared
coconut oil of any implication in the development of coronary heart disease (CHD).
For example, when Frantz and Carey (1961) fed an additional 810 kcal/day fat
supplement for a whole month to males with high normal serum cholesterol levels,
there was no significant difference from the original levels even though the fat
supplement was hydrogenated coconut oil.
Halden and Lieb (1961) also showed similar results in a group of
hyperchole-sterolemics when coconut oil was included in their diets. Original
serum cholesterol levels were reported as 170 to 370 mg/dl. Straight coconut oil
produced a range from 170 to 270 mg/dl. Coconut oil combined with 5% sunflower
oil and 5% olive oil produced a range of 140 to 240 mg/dl.
Earlier, Hashim and colleagues (1959) had shown quite clearly that feeding a
fat supplement to hypercholesterolemics, where half of the supplement (21% of
energy) was coconut oil (and the other half was safflower oil), resulted in
significant reductions in total serum cholesterol. The reductions averaged -29%
and ranged from -6.8 to -41.2%.
And even earlier, Ahrens and colleagues (1957) had shown that adding coconut
oil to the diet of hypercholesterolemics lowers serum cholesterol from, e.g.,
450 mg/dl to 367 mg/dl. This is hardly a cholesterol-raising effect.
Bierenbaum et al (1967) followed 100 young men with documented myocardial
infarction for 5 years on diets with fat restricted to 28% of energy. There was
no significant difference between the two different fat mixtures (50/50 corn and
safflower oils or 50/50 coconut and peanut oils), which were fed as half of the
total fat allowance; both diets reduced serum cholesterol. This study clearly
showed that 7% of energy as coconut oil was as beneficial to the 50 men who
consumed it as for the 50 men who consumed 7% of energy as other oils such as
corn oil or safflower. Both groups fared better than the untreated controls.
More recently, Sundram et al (1994) fed whole foods diets to healthy
normo-cholesterolemic males, where approximately 30% of energy was fat. Lauric
acid (C12:0) and myristic acid (C14:0) from coconut oil supplied approximately
5% of energy. Relative to the baseline measurements of the subjects prior to the
experimental diet, this lauric and myristic acid-rich diet showed an increase in
total serum cholesterol from 166.7 to 170.0 mg/dl (+1.9%), a decrease in low
density lipoprotein cholesterol (LDL-C) from 105.2 to 104.4 mg/dl (-0.1%), an
increase in high density lipoprotein cholesterol (HDL-C) from 42.9 to 45.6 mg/dl
(+6.3%). There was a 2.4% decrease in the LDL-C/HDL-C ratio from 2.45 to 2.39.
These findings indicate a favorable alteration in serum lipoprotein balance was
achieved when coconut oil was included in a whole food diet at 5% of energy.
Tholstrup et al (1994) report similar results with whole foods diets high in
lauric and myristic acids from palm kernel oil. The HDL cholesterol levels
increased significantly from baseline values (37.5 to 46.0 mg/dl, P<0.01) and
the LDL-C/HDL-C ratios decreased from 3.08 to 2.69. The increase in total
cholesterol was from 154.7 (baseline) to 170.9 mg/dl on the experimental diet.
Ng et al (1991) fed 75% of the fat ration as coconut oil (24% of energy) to
83 adult normocholesterolemics (61 males and 22 females). Relative to baseline
values, the highest values on the experimental diet for total cholesterol was
increased 17% (169.6 to 198.4 mg/dl), HDL cholesterol was increased 21.4% (44.3
to 53.8 mg/dl), and the LDL-C/HDL-C ratio was decreased 3.6% (2.51 to 2.42).
When unprocessed coconut oil is added to an otherwise normal diet, there is
frequently no change in the serum cholesterol although some studies have shown a
decrease in total cholesterol. For example, when Ginsberg et al provided an
"Average American" diet with 2-3 times more myristic acid (C14:0), 4.5 times
more lauric acid (C12:0), and 1.2 times more palmitic and stearic acid (C16:0
and C18:0) than their "Mono[unsaturated]" diet and the National Cholesterol
Education Program "Step 1" diet, there was no increase in serum cholesterol, and
in fact, serum cholesterol levels for this diet group fell approximately 3% from
177.1 mg% to 171.8 mg% during the 22 week feeding trial.
It appears from many of the research reports that the effect coconut oil has
on serum cholesterol is the opposite in individuals with low serum cholesterol
values and those with high serum values. We see that there may be a raising of
serum total cholesterol, LDL cholesterol and especially HDL cholesterol in
individuals with low serum cholesterol. On the other hand there is lowering of
total cholesterol and LDL cholesterol in hypercholesterolemics as noted above.
Studies that supposedly showed a hypercholesterolemic effect of
coconut oil feeding, in fact, usually only showed that coconut oil was not as
effective at lowering the serum cholesterol as was the more unsaturated fat
being compared. This appears to be in part because coconut oil does not drive
cholesterol into the tissues as does the more polyunsaturated fats. The chemical
analysis of the atheroma shows that the fatty acids from the cholesterol esters
are 74% unsaturated (41% is polyunsaturated) and only 24% are saturated. None of
the saturated fatty acids were reported to be lauric acid or myristic acid
(Felton et al 1994).
Should coconut oil be used to prevent coronary heart disease?
There is another aspect to the coronary heart disease picture. This is
related to the initiation of the atheromas that are reported to be blocking
arteries. Recent research is suggestive that there is a causative role for the
herpes virus and cytomegalovirus in the initial formation of atherosclerotic
plaques and the recloging of arteries after angioplasty. (New York Times
1991) What is so interesting is that the herpes virus and cytomegalovirus are
both inhibited by the antimicrobial lipid monolaurin; but monolaurin is not
formed in the body unless there is a source of lauric acid in the diet. Thus,
ironically enough, one could consider the recommendations to avoid coconut and
other lauric oils as contributing to the increased incidence of coronary heart
disease.
Perhaps more important than any effect of coconut oil on serum cholesterol is
the additional effect of coconut oil on the disease fighting capability of the
animal or person consuming the coconut oil.
IV. COCONUT OIL AND CANCER
Lim-Sylianco (1987) has reviewed 50 years of literature showing
anticarcinogenic effects from dietary coconut oil. These animal studies show
quite clearly the nonpromotional effect of feeding coconut oil.
In a study by Reddy et al (1984) straight coconut oil was more inhibitory
than MCT oil to induction of colon tumors by azoxymethane. Chemically induced
adenocarcinomas differed 10-fold between corn oil (32%) and coconut oil (3%) in
the colon. Both olive oil and coconut oil developed the low levels (3%) of the
adenocarcinomas in the colon, but in the small intestine animals fed coconut oil
did not develop any tumors while 7% of animals fed olive oil did.
Studies by Cohen et al (1986) showed that the nonpromotional effects of
coconut oil were also seen in chemically induced breast cancer. In this model,
the slight elevation of serum cholesterol in the animals fed coconut oil was
protective as the animals fed the more polyunsaturated oil had reduced serum
cholesterol and more tumors. The authors noted that "...an overall inverse trend
was observed between total serum lipids and tumor incidence for the 4 [high fat]
groups."
This is an area that needs to be pursued.
V. COCONUT OIL ANTIMICROBIAL BENEFITS
I would now like to review for you some of the rationale for the use of
coconut oil as a food that will serve as the raw material to provide potentially
useful levels of antimicrobial activity in the individual.
The lauric acid in coconut oil is used by the body to make the same
disease-fighting fatty acid derivative monolaurin that babies make from the
lauric acid they get from their mothers= milk. The monoglyceride monolaurin is
the substance that keeps infants from getting viral or bacterial or protozoal
infections. Until just recently, this important benefit has been largely
overlooked by the medical and nutrition community.
Recognition of the antimicrobial activity of the monoglyceride of lauric acid
(monolaurin) has been reported since 1966. The seminal work can be credited to
Jon Kabara. This early research was directed at the virucidal effects because of
possible problems related to food preservation. Some of the early work by
Hierholzer and Kabara (1982) that showed virucidal effects of monolaurin on
enveloped RNA and DNA viruses was done in conjunction with the Center for
Disease Control of the US Public Health Service with selected prototypes or
recognized representative strains of enveloped human viruses. The envelope of
these viruses is a lipid membrane.
Kabara (1978) and others have reported that certain fatty acids (e.g.,
medium-chain saturates) and their derivatives (e.g., monoglycerides) can have
adverse effects on various microorganisms: those microorganisms that are
inactivated include bacteria, yeast, fungi, and enveloped viruses.
The medium-chain saturated fatty acids and their derivatives act by
disrupting the lipid membranes of the organisms (Isaacs and Thormar 1991)
(Isaacs et al 1992). In particular, enveloped viruses are inactivated in both
human and bovine milk by added fatty acids (FAs) and monoglycerides (MGs)
(Isaacs et al 1991) as well as by endogenous FAs and MGs (Isaacs et al 1986,
1990, 1991, 1992; Thormar et al 1987).
All three monoesters of lauric acid are shown to be active antimicrobials,
i.e., alpha-, alpha'-, and beta-MG. Additionally, it is reported that the
antimicrobial effects of the FAs and MGs are additive and total concentration is
critical for inactivating viruses (Isaacs and Thormar 1990).
The properties that determine the anti-infective action of lipids are related
to their structure; e.g., monoglycerides, free fatty acids. The monoglycerides
are active, diglycerides and triglycerides are inactive. Of the saturated fatty
acids, lauric acid has greater antiviral activity than either caprylic acid
(C-10) or myristic acid (C-14).
The action attributed to monolaurin is that of solubilizing the lipids and
phospholipids in the envelope of the virus causing the disintegration of the
virus envelope. In effect, it is reported that the fatty acids and
monoglycerides produce their killing/inactivating effect by lysing the (lipid
bilayer) plasma membrane. However, there is evidence from recent studies that
one antimicrobial effect is related to its interference with signal transduction
(Projan et al 1994).
Some of the viruses inactivated by these lipids, in addition to HIV, are the
measles virus, herpes simplex virus-1 (HSV-1), vesicular stomatitis virus (VSV),
visna virus, and cytomegalovirus (CMV). Many of the pathogenic organisms
reported to be inactivated by these antimicrobial lipids are those known to be
responsible for opportunistic infections in HIV-positive individuals. For
example, concurrent infection with cytomegalovirus is recognized as a serious
complication for HIV+ individuals (Macallan et al 1993). Thus, it would appear
to be important to investigate the practical aspects and the potential benefit
of an adjunct nutritional support regimen for HIV-infected individuals, which
will utilize those dietary fats that are sources of known anti-viral,
anti-microbial, and anti-protozoal monoglycerides and fatty acids such as
monolaurin and its precursor lauric acid.
No one in the mainstream nutrition community seems to have recognized the
added potential of antimicrobial lipids in the treatment of HIV-infected or AIDS
patients. These antimicrobial fatty acids and their derivatives are essentially
non-toxic to man; they are produced in vivo by humans when they ingest those
commonly available foods that contain adequate levels of medium-chain fatty
acids such as lauric acid. According to the published research, lauric acid is
one of the best "inactivating" fatty acids, and its monoglyceride is even more
effective than the fatty acid alone (Kabara 1978, Sands et al 1978, Fletcher et
al 1985, Kabara 1985).
The lipid coated (envelop) viruses are dependent on host lipids for their
lipid constituents. The variability of fatty acids in the foods of individuals
accounts for the variability of fatty acids in the virus envelop and also
explains the variability of glycoprotein expression.
Loss of lauric acid from the American diet
Increasingly, over the past 40 years, the American diet has undergone major
changes. Many of these changes involve changes of fats and oils. There has been
an increasing supply of the partially hydrogenated trans-containing
vegetable oils and a decreasing amount of the lauric acid-containing oils. As a
result, there has been an increased consumption of trans fatty acids and
linoleic acid and a decrease in the consumption of lauric acid. This type of
change in diet has an effect on the fatty acids the body has available for
metabolic activities.
VI. LAURIC ACID IN FOODS
The coconut producing countries
Whole coconut as well as extracted coconut oil has been a mainstay in the
food supply in many countries in parts of Asia and the Pacific Rim throughout
the centuries. Recently though, there has been some replacement of coconut oil
by other seed oils. This is unfortunate since the benefits gained from consuming
an adequate amount of coconut oil are being lost.
Based on the per capita intake of coconut oil in 1985 as reported by Kaunitz
(1992), the per capita daily intake of lauric acid can be approximated. For
those major producing countries such as the Philippines, Indonesia, and Sri
Lanka, and consuming countries such as Singapore, the daily intakes of lauric
acid were approximately 7.3 grams (Philippines), 4.9 grams (Sri Lanka), 4.7
grams (Indonesia), and 2.8 grams (Singapore). In India, intake of lauric acid
from coconut oil in the coconut growing areas (e.g., Kerala) range from about 12
to 20 grams per day (Eraly 1995), whereas the average for the rest of the
country is less than half a gram. An average high of approximately 68 grams of
lauric acid is calculated from the coconut oil intake previously reported by
Prior et al (1981) for the Tokelau Islands. Other coconut producing countries
may also have intakes of lauric acid in the same range.
The US experience
In the United States today, there is very little lauric acid in most of the
foods. During the early part of the 20th Century and up until the late 1950s
many people consumed heavy cream and high fat milk. These foods could have
provided approximately 3 grams of lauric acid per day to many individuals. In
addition, desiccated coconut was a popular food in homemade cakes, pies and
cookies, as well as in commercial baked goods, and 1-2 tablespoons of desiccated
coconut would have supplied 1-2 grams of lauric acid. Those foods made with the
coconut oil based shortenings would have provided additional amounts.
Until two years ago, some of the commercially sold popcorn, at least in movie
theaters, had coconut oil as the oil. This means that for those people lucky
enough to consume this type of popcorn the possible lauric acid intake was 6
grams or more in a three (3) cup order.
Some infant formulas (but not all) have been good sources of lauric acid for
infants. However, in the past 3-4 years there has been reformulation with a loss
of a portion of coconut oil in these formulas, and a subsequent lowering of the
lauric acid levels.
Only one US manufactured enteral formula contains lauric acid (e.g.,
Impact7); this is normally used in hospitals for tube feeding; it is reported to
be very effective in reversing severe weight loss in AIDS patients, but it is
discontinued when the patients leave the hospital because it is not sufficiently
palatable for oral use. The more widely promoted enteral formulas (e.g.,
Ensure7, Nutren7) are not made with lauric oils, and, in fact, many are made
with partially hydrogenated oils.
There are currently some candies sold in the US that are made with palm
kernel oil, and a few specialty candies made with coconut oil and desiccated
coconut. These can supply small amounts of lauric acid.
Cookies such as macaroons, if made with desiccated coconut, are good sources
of lauric acid, supplying as much as 6 grams of lauric acid per macaroon (Red
Mill). However, these cookies make up a small portion of the cookie market. Most
cookies in the United States are no longer made with coconut oil shortenings;
however, there was a time when many US cookies (e.g., Pepperidge Farm) were
about 25% lauric acid.
Originally, one of the largest manufacturers of cream soups used coconut oil
in the formulations. Many popular cracker manufacturers also used coconut oil as
a spray coating. These products supplied a small amount of lauric acid on a
daily basis for some people.
How much lauric acid is needed?
It is not known exactly how much food made with lauric oils is needed in
order to have a protective level of lauric acid in the diet. Infants probably
consume between 0.3 and 1 gram per kilogram of body weight if they are fed human
milk or an enriched infant formula that contains coconut oil. This amount
appears to have always been protective. Adults could probably benefit from the
consumption of 10 to 20 grams of lauric acid per day. Growing children probably
need about the same amounts as adults.
VII. RECOMMENDATIONS
The coconut oil industry needs to make the case for lauric acid now. It
should not wait for the rapeseed industry to promote the argument for including
lauric acid because of the increased demand for laurate. In fact lauric acid may
prove to be a conditionally essential saturated fatty acid, and the research to
establish this fact around the world needs to be vigorously promoted.
Although private sectors need to fight for their commodity through the
offices of their trade associations, the various governments of coconut
producing countries need to put pressure on WHO, FAO, and UNDP to recognizes the
health importance of coconut oil and the other coconut products. Moreover, those
representatives who are going to do the persuading need to believe that their
message is scientifically correct -- because it is.
Among the critical foods and nutrition "buzz words" for the 21st Century is
the term "functional foods." Clearly coconut oil fits the designation of a very
important functional food.
About the Author
Mary G. Enig, PhD is the author of Know Your Fats: The Complete Primer
for Understanding the Nutrition of Fats, Oils, and Cholesterol,
Bethesda Press, May 2000.
The book is available at Amazon
REFERENCES
- Awad AB. Effect of dietary lipids on composition and glucose utilization by
rat adipose tissue. Journal of Nutrition 111:34-39, 1981.
- Bierenbaum JL, Green DP, Florin A, Fleishman AI, Caldwell AB. Modified-fat
dietary management of the young male with coronary disease: a five-year report.
Journal of the American Medical Association 202:1119-1123;1967.
- Blackburn GL, Kater G, Mascioli EA, Kowalchuk M, Babayan VK, kBistrian BR. A
reevaluation of coconut oil's effect on serum cholesterol and atherogenesis.
The Journal of the Philippine Medical Association 65:144-152;1989.
- Castelli WP. Editorial: Concerning the possibility of a nut... Archives of
Internal Medicine 152:1371-2;1992.
- Cohen LA, Thompson DO, Maeura Y, Choi K, Blank M, Rose DP. Dietary fat and
mammary cancer. I. Promoting effects of different dietary fats on N-nitrosomethylurea-induced
rat mammary tumorigenesis. Journal of the National Cancer Institute
77:33;1986.
- Cohen LA, Thompson DO, Choi K, Blank M, Rose DP. Dietary fat and mammary
cancer. II. Modulation of serum and tumor lipid composition and tumor
prostaglandins by different dietary fats: Association with tumor incidence
patterns. Journal of the National Cancer Institute 77:43;1986.
- Eraly MG. IV. Coconut oil and heart attack. Coconut and Coconut Oil in
Human Nutrition, Proceedings. Symposium on Coconut and Coconut Oil in Human
Nutrition. 27 March 1994. Coconut Development Board, Kochi, India, 1995, pp
63-64.
- Enig MG. Diet, serum cholesterol and coronary heart disease, in Mann GV (ed):
Coronary Heart Disease: The Dietary Sense and Nonsense. Janus Publishing,
London, 1993, pp 36-60.
- Felton CV, Crook D, Davies MJ, Oliver MF. Dietary polyunsaturated fatty acids
and composition of human aortic plaques. Lancet, 344:1195-1196;1994.
- Fletcher RD, Albers AC, Albertson JN, Kabara JJ. Effects of monoglycerides on
mycoplasma pneumoniae growth, in The Pharmacological Effect of Lipids II
(JJ Kabara, ed) American Oil Chemists' Society, Champaign IL, 1985,
pp.59-63.
- Florentino RF, Aquinaldo AR. Diet and cardiovascular disease in the
Philippines. The Philippine Journal of Coconut Studies 12:56-70;1987.
- Halden VW, Lieb H. Influence of biologically improved coconut oil products on
the blood cholesterol levels of human volunteers. Nutr Dieta
3:75-88;1961.
- Hashim SA, Clancy RE, Hegsted DM, Stare FJ. Effect of mixed fat formula
feeding on serum cholesterol level in man. American Journal of Clinical
Nutrition. 7:30-34;1959.
- Hegsted DM, McGandy RB, Myer ML, Stare FJ. Quantitative effects of dietary
fat on serum cholesterol in man. American Journal of Clinical Nutrition.
17:281-295;1965.
- Hierholzer, J.C. and Kabara, J.J. In vitro effects of monolaurin compounds on
enveloped RNA and DNA viruses. Journal of Food Safety 4:1-12;1982.
- Hostmark AT, Spydevold O, Eilertsen E. Plasma lipid concentration and liver
output of lipoproteins in rats fed coconut fat or sunflower oil. Artery
7:367-383, 1980.
- Isaacs CE, Thormar H. Membrane-disruptive effect of human milk: inactivation
of enveloped viruses. Journal of Infectious Diseases 154:966-971;1986.
- Isaacs CE, Thormar H. Human milk lipids inactivated enveloped viruses. in
Breastfeeding, Nutrition, Infection and Infant Growth in Developed and Emerging
Countries (Atkinson SA, Hanson LA, Chandra RK, eds) Arts Biomedical
Publishers and Distributors, St. John's NF, Canada, 1990.
- Isaacs CE, Thormar H. The role of milk-derived antimicrobial lipids as
antiviral and antibacterial agents in Immunology of Milk and the Neonate
(Mestecky J, et al, eds) Plenum Press, New York, 1991.
- Isaacs CE, Schneidman K. Enveloped Viruses in Human and Bovine Milk are
Inactivated by Added Fatty Acids(FAs) and Monoglycerides(MGs). FASEB Journal.
Abstract 5325, p.A1288, 1991.
- Isaacs CE, Kashyap S, Heird WC, Thormar H. Antiviral and antibacterial lipids
in human milk and infant formula feeds. Archives of Disease in Childhood
65:861-864;1990.
- Isaacs CE, Litov RE, Marie P, Thormar H. Addition of lipases to infant
formulas produces antiviral and antibacterial activity. Journal of
Nutritional Biochemistry 3:304-308;1992.
- Kabara JJ. Fatty acids and derivatives as antimicrobial agents -- A review,
in The Pharmacological Effect of Lipids (JJ Kabara, ed) American Oil
Chemists' Society, Champaign IL, 1978,
- Kabara JJ. Inhibition of staphylococcus aureaus in The
Pharmacological Effect of Lipids II (JJ Kabara, ed) American Oil Chemists'
Society, Champaign IL, 1985, pp.71-75.
- Kaunitz H, Dayrit CS. Coconut oil consumption and coronary heart disease.
Philippine Journal of Internal Medicine 30:165-171;1992.
- Keys A, Anderson JT, Grande F. Prediction of serum-cholesterol responses of
man to changes in the diet. Lancet, 959;1957.
- Kurup PA, Rajmohan T. II. Consumption of coconut oil and coconut kernel and
the incidence of atherosclerosis. Coconut and Coconut Oil in Human Nutrition,
Proceedings. Symposium on Coconut and Coconut Oil in Human Nutrition. 27 March
1994. Coconut Development Board, Kochi, India, 1995, pp 35-59.
- Lim-Sylianco CY. Anticarcinogenic effect of coconut oil. The Philippine
Journal of Coconut Studies 12:89-102;1987.
- Macallan DC, Noble C, Baldwin C, Foskett M, McManus T, Griffin GE.
Prospective analysis of patterns of weight change in stage IV hulman
immunodeficiency virus infection. American Journal of Clinical Nutrition
58:417-24;1993.
- Mann GV. A short history of the diet/heart hypothesis, in Mann GV (ed):
Coronary Heart Disease: The Dietary Sense and Nonsense. Janus Publishing,
London, 1993, pp 1-17.
- Mendis S, Wissler RW, Bridenstine RT, Podbielski FJ. The effects of replacing
coconut oil with corn oil on human serum lipid profiles and platelet derived
factors active in atherogenesis. Nutrition Reports International
40:No.4;Oct.1989.
- New York Times, Medical Science, Tuesday, January 29, 1991. Common
virus seen as having early role in arteries' clogging (byline Sandra Blakeslee).
- Ng TKW, Hassan K, Lim JB, Lye MS, Ishak R. Nonhypercholesterolemic effects of
a palm-oil diet in Malaysian volunteers. American Journal of Clinical
Nutrition, 53:1015S-1020S;1991.
- Prior IA, Davidson F, Salmond CE, Czochanska Z. Cholesterol, coconuts, and
diet on Polynesian atolls: a natural experiment: the Pukapuka and Tokelau Island
studies. American Journal of Clinical Nutrition 34:1552-1561;1981.
- Projan SJ, Brown-Skrobot S, Schlievert PM, Vandenesch F, Novick RP. Glycerol
monolaurate inhibits the production of beta-lactamase, toxic shock toxin-1, and
other staphylococcal exoproteins by interefering with signal transduction.
Journal of Bacteriology. 176:4204-4209;1994.
- Ravnskov U. Quotation bias in reviews of the diet-heart idea. Journal of
Clinical Epidemiology 48:713-719;1995.
- Reddy BS, Maeura Y. Tumor promotion of dietary fat in azoxymethane-induced
colon carcinogenesis in female F 344 rats. Journal of the National Cancer
Institute 72:745- 750;1984.
- Sands JA, Auperin DD, Landin PD, Reinhardt A, Cadden SP. Antiviral effects of
fatty acids and derivatives: lipid-containing bacteriophages as a model system
in The Pharmacological Effect of Lipids (JJ Kabara, ed) American Oil
Chemists' Society, Champaign IL, 1978, pp 75-95.
- Smith RL. The Cholesterol Conspiracy. Warren H Green Inc. St. Louis,
Missouri, 1991.
- Sundram K, Hayes KC, Siru OH. Dietary palmitic acid results in lower serum
cholesterol than does a lauric-myristic acid combination in normolipemic humans.
American Journal of Clinical Nutrition 59:841-846;1994.
- Tholstrup T, Marckmann P, Jespersen J, Sandstrom B. Fat high in stearic acid
favorably affects blood lipids and factor VII coagulant activity in comparison
with fats high in palmitic acid or high in myristic and lauric acids.
American Journal of Clinical Nutrition 59:371-377;1994.
- Thormar H, Isaacs EC, Brown HR, Barshatzky MR, Pessolano T. Inactivation of
enveloped viruses and killing of cells by fatty acids and monoglycerides.
Antimicrobial agents and chemotherapy 1987;31:27-31.
- Willett W. Editorial: Challenges for public health nutrition in the 1990s.
American Journal of Public Health. 80:1295-1298;1990.
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