Date post: | 20-Aug-2015 |
Category: |
Food |
Upload: | laurence-eyres |
View: | 103 times |
Download: | 0 times |
COCONUT OIL – ARE ITS HEALTH
CLAIMS JUSTIFIED? Dr.Laurence Eyres ECG Ltd
Chairman NZIC Oils and Fats Group
November 2014
WHAT IS COCONUT OIL?
Edible oil industry production of commodity
crude to RBD- Own experience in 1974
Newmarket
Niche production of Extra virgin oil-definition
What’s all the fuss about? Market rapid growth
Confusion with MCT oil (Medium chain
triglycerides)
Conclusion as to the claimed health benefits
COCONUTS
Tropical fruit grown year round
Oil within the meat of the coconut
Contained within cells
Composition Percentage of Fresh Coconut Meat by Weight
Moisture 50
Oil 34
Ash 2.2
Fibre 3
Protein 3.5
Carbohydrates 7.3
TRADITIONAL USES OF CNO AND HCNO
Most of the oil has been used as HCNO( the fully
hydrogenated oil -no trans!) termed a
confectionery fat. (same use as fully hardened
palm kernel oil).Increase in melt point from 26 to
35 degrees C
CF 92-kremelta-home made chocolate rice
krispies, biscuit fillings, caramels etc.
Unhydrogenated oil resurrected by marketers as
the answer to all human ills!
WEBSITE AND CELEBRITY ENDORSEMENT
OF CNO
No evidence to back claims by celebrities for
exaggeratde health claims for coconut oil.
These are statements-only anecdotal hype
Erroneous classification of coconut oil triglyceride
structure-claims based on the sound work done on
genuine MCT oil
EXTRA VIRGIN COCONUT OIL
Colourless when liquid
Characteristic mild aroma of coconut
Oil quality
Acid Value-low <4mg KOH/g oil
Measures hydrolysis of oil
Peroxide Value-low <10 meq peroxide/g oil
Measures oxidation of oil
WONG, M., EYRES, L., RAVETTI, L. 2012. Modern aqueous oil extraction: Centrifugation systems for olive and avocado oils. In: Green Vegetable Oil Processing. Editors: Proctor, A. & Farr, W. The American Oil Chemists Society, AOCS
COMPOSITION OF COCONUT OIL
Predominantly triacylglycerols
Made up of the following fatty acids
C6, 8 and 10 saturated fatty acids 17%
C12 saturated fatty acid (lauric) 47-48%
Myristic and palmitic saturated fatty acids 24%
Unsaturates 7-8%
Healthy?
MEDIUM CHAIN FATTY ACIDS AND
TRIGLYCERIDES
Explanation of terms
Medium chain fatty acids 8, 10 and 12 carbon fatty acids
MCT’s are comprised C8 and C10 only not C12
Coconut oil is 47-48% C12 contains virtually no MCT’s
MCT studied for their carbohydrate-like dietary
mechanism( They contain about 70% C8 and 30%C10)
Coconut oil and MCT’s are miles apart
Bach, A. C., & Babayan, V. K. (1982). Medium-chain triglycerides: an update. Am J
Clin Nutr, 36(5), 950-962.
MANUFACTURE OF MCT OIL-FROM THE
60’S
CNO or palm kernel oil are hydrolysed to their
fatty acids
These are distilled the prize is C12 fatty acid
(48%)used to make surfactants and other
chemicals-such as sodium lauryl sulphate
The residual C6,8 and 10 fatty acids are
separated (lower boiling)
They are then re-esterified back into triglycerides
Bleached and deodorised
Product is fully saturated, bland,colourless,stable
and has unique properties in nutrition
COMPARING COCONUT OIL WITH MCT OIL
Fatty acids Coconut Medium chain triglycerides
Butyric 4:00 0 0
Caproic 6:0 1 <2
Caprylic 8:00 9 50-80
Capric 10:00 7 20-50
Lauric 12:00 47 <3
Myristic14:00 16.5 <1
Palmitic16:00 7.5 0
Stearic18:00 3 0
Oleic18:1 cis 6.4 0
Triglyceride carbon number analysis of CNO vs. MCT oil MCT oil (Croda) Coconut oil Mol Weight
Tricaproin C24 24 zero 471
TricaprylinC26 25 zero 499
Tricaprin C28 28 0.5 527
Tricaprin C30 10-10-10 10 3 555
C32 <3 14 583
C34 <1 17.5 611
C36 Trilaurin LaLaLa plus others 0 20 639
C38 0 16 667
C40 0 10 695
C42 0 7 723
LAURIC ACID TWELVE CARBON SATURATED
FATTY ACID
Whilst chemically Lauric acid (C 12:0) could
possibly be described as a medium chain fatty
acid-biologically it behaves as a typical saturated
fatty acid like myristic and palmitic.
CONCLUSION 1
Coconut oil is NOT composed of medium chain
triglycerides
Any referring to CNO and its similarity in the
metabolism of MCT oil is erroneous and
misleading
Coconut oil does not behave the same as MCT’s
and it is totally erroneous and scientifically
wrong to call coconut oil an MCT and thus any
analogies comparing coconut oil with clinical
work on MCT’s are void.
PEER REVIEWED CLINICAL
EVIDENCE ON CNO ROLE IN CVD
We found no evidence to suggest that CNO is
beneficial other than as a source of energy
Replacement of some CNO with PUFA resulted
in more favourable lipid profiles
Coconut flesh, cream and milk when consumed
with fish, vegetables and fruit can be considered
a healthy diet
NORDIC REVIEW
There was convincing evidence that partial
replacement of SFA with PUFA decreases the
risk of CVD, especially in men. This finding was
supported by an association with biomarkers of
PUFA intake; the evidence of a beneficial effect of
dietary total PUFA, n-6 PUFA, and linoleic acid
(LA) on CVD mortality was limited suggestive.
Evidence for a direct association between total
fat intake and risk of T2DM was inconclusive,
whereas there was limited-suggestive evidence
from biomarker studies that LA is inversely
associated with the risk of T2DM.
LITERATURE SEARCH
Searches were conducted in the Scopus and
Medline databases and bibliographies in
published literature and on websites promoting
coconut oil were examined. The few papers and
studies (n=23) identified for inclusion in this
review demonstrates the paucity of quality
studies, reviews or meta-analyses that examine
the effects of coconut in its own right. Even fewer
have studied the effects of consumption of
coconut or coconut products on cardiovascular
disease outcomes.
CONCLUSION 2
No evidence from human clinical trials to suggest
that CNO can be classified as a healthy oil
SUMMARY CLINICAL PAPERS REVIEW
In summary, while the level of evidence on coconut itself and risk factors for heart disease is mostly poor quality, the evidence suggests that consumption of coconut oil raises total cholesterol, HDL and LDL, although in clinical trials this did not raise them as much as butter.
In the clinical trials included in this review, the effects of coconut oil on triglyceride levels versus unsaturated oils were generally not significant.
Cox, C., Sutherland, W., Mann, J., de Jong, S., Chisholm, A., & Skeaff, M. (1998). Effects of dietary coconut oil, butter and safflower oil on plasma lipids, lipoproteins and lanosterol levels. Eur J Clin Nutr, 52(9), 650-654.
CONCLUSION 3
For consumers living in New Zealand who are on
a Western style diet, based on current evidence it
would be inadvisable to switch from unsaturated
oils to coconut oil. It is likely that this would lead
to less favourable lipid profiles and so a potential
increased risk from CHD.
RECOMMENDATION
Consumers who are using a lot of coconut oil due
to the current fad would be well advised to either
limit its use, or to blend in some unsaturated cold
pressed monounsaturated oils such as olive,
avocado or canola oil. Although it may be a better
choice than butter, coconut oil cannot be
recommended as a suitable alternative to non-
hydrogenated vegetable oils.
http://www.heartfoundation.org.nz/uploads/Evi
dence_paper_coconut_August_2014.pdf
POPULATION STUDIES
Indigenous populations who consume traditional diets with coconut products along with fish and vegetables (unsaturated fats and fibre) combined with a physically active lifestyle are unlikely to be at risk of cardiovascular disease from the consumption of coconut products. The situation for indigenous populations who eat a traditional diet is vastly different to that of people consuming a typical “Western” diet.
For other populations, coconut oil is 92% saturated and nothing in the literature disputes the fact that it acts as a saturated fat and raises total cholesterol, LDL cholesterol and HDL cholesterol.
CONCLUSION 4
Pacific island populations have not normally consumed coconut oil per.se., instead coconut oil is consumed as a component of coconut flesh or coconut milk.
The Pacific Island communities have had their traditional diets modified enormously and high fat and high sugar processed foods have been incorporated into their local culinary culture with adverse effects on obesity and health. Making changes in the food supply to improve access and availability of locally produced traditional foods may allow taste preferences to be met and may be a better option than encouraging behaviour change alone.
WRITTEN REVIEWS
NZ Heart Foundation website
Food New Zealand-October and December issues
Oils and fats website
http://www.oilsfats.org.nz/ For Oils and Fats
Group