Post #13502

[Guest guest]

Hi Tim:

I am reluctant to swallow, as if they were from an independent

source, a list of studies on coconut oil from a website that goes by

the name: www.coconutoil.com

So instead I entered " coconut oil " in the search window at Pubmed,

hit 'enter' and it came up with 1005 references. While it would be

nice to read/review each of the full studies in turn, I decided that

taking a look at the abstracts of the first ten would have to do.

This is what I found:

The first appears to be saying that black pepper has been shown to

reverse many of the apparently negative effects of adding coconut oil

to the diet of rats:

" Antioxidant efficacy of black pepper (Piper nigrum L.) and piperine

in rats with high fat diet induced oxidative stress.

Vijayakumar RS, Surya D, Nalini N.

Department of Biochemistry, malai University, malai Nagar,

Tamilnadu, India.

The present study was aimed to explore the effect of black pepper

(Piper nigrum L.) on tissue lipid peroxidation, enzymic and non-

enzymic antioxidants in rats fed a high-fat diet. Thirty male Wistar

rats (95-115 g) were divided into 5 groups. They were fed standard

pellet diet, high-fat diet (20% coconut oil, 2% cholesterol and

0.125% bile salts), high-fat diet plus black pepper (0.25 g or 0.5

g/kg body weight), high-fat diet plus piperine (0.02 g/kg body

weight) for a period of 10 weeks. Significantly elevated levels of

thiobarbituric acid reactive substances (TBARS), conjugated dienes

(CD) and significantly lowered activities of superoxide dismutase

(SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-

transferase (GST) and reduced glutathione (GSH) in the liver, heart,

kidney, intestine and aorta were observed in rats fed the high fat

diet as compared to the control rats. Simultaneous supplementation

with black pepper or piperine lowered TBARS and CD levels and

maintained SOD, CAT, GPx, GST, and GSH levels to near those of

control rats. The data indicate that supplementation with black

pepper or the active principle of black pepper, piperine, can reduce

high-fat diet induced oxidative stress to the cells.

PMID: 15231065 [PubMed - in process] "

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The second study listed by my Pubmed search is this one:

" Effect of dietary cholesterol with or without saturated fat on

plasma lipoprotein cholesterol levels in the laboratory opossum

(Monodelphis domestica) model for diet-induced hyperlipidaemia.

Kushwaha RS, VandeBerg JF, VandeBerg JL.

Department of Physiology and Medicine, Southwest Foundation for

Biomedical Research, San , Texas 78245-0459, USA.

kush@s... "

The abstract contains the following quote: " .......... Dietary

coconut oil and lard had similar effects on plasma lipoprotein

cholesterol concentrations in the susceptible line of opossums "

Of course opossums are not humans anymore than mice are, but I doubt

the investigators were studying opossums because of an urgently

perceived need to find a way do something to lower cholesterol levels

of the opossum : ^ )))

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The third study, if I am reading it right, used coconut oil, EPA and

soybean oil for the purpose of showing that EPA had properties

superior to those of soybean oil. The abstract doesn't seem to

indicate any significance to the coconut oil - but if it had been

beneficial I have no doubt they would have mentioned it.

" Omega-3 fatty acid ethyl-eicosapentaenoate, but not soybean oil,

attenuates memory impairment induced by central IL-1beta

administration.

Song C, Horrobin D. "

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The fourth study, where the issue appears to be the effectiveness of

various substances as a base in ointments for the topical delivery of

drugs, does not seem to have relevance to the health effects of the

substances used (one of which was coconut oil).

" Lipid nano/submicron emulsions as vehicles for topical flurbiprofen

delivery.

Fang JY, Leu YL, Chang CC, Lin CH, Tsai YH "

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For the fifth study listed, the issue being investigated appears to

be the growth rate of young pigs fed supplements of either

flax/linseed oil; coconut oil; or fish oil. It concluded that the

pigs did better on the linseed oil than on either the coconut oil or

fish oil. And SIGNIFICANTLY better than on coconut oil, it says.

Yes. Pigs are not humans, but I believe they are some of the more

closely matched species to ours where fats are concerned (I.E. much

more closely related than mice or rats for example).

" Influence of dietary linseed, fish and coconut oil on growth

performance of growing pigs kept on small holdings in central Vietnam.

Nguyen LQ, Everts H, Beynen AC. "

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The sixth study appears to indicate that a 4% coconut oil diet is

deficient in essential fats whereas a diet including 4% soybean oil

is not. But the use in this study of **hydrogenated** coconut oil,

as well as a zinc deficiency, makes the study of dubious relevance I

think.

" Effect of low-zinc status and essential fatty acids deficiency on

the activities of aspartate aminotransferase and alanine

aminotransferase in liver and serum of albino rats.

Ajayi OB, Odutuga A. "

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In the seventh study the use of coconut oil as a base for mosquito

repellents appears irrelevant to our purposes.

" Evaluation of botanicals as repellents against mosquitoes.

Das NG, Baruah I, Talukdar PK, Das SC. "

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In the eighth study it was not the properties of coconut oil that

were being investigated directly. And the study results were not

affected by type of oil used. (Another irrelevant study I think).

" Dietary oxidized cholesterol increases expression and activity of

antioxidative enzymes and reduces the concentration of glutathione in

the liver of rats.

Ringseis R, Eder K. "

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I suggest you take a VERY CLOSE look at study # 9 before continuing

to use coconut oil. Here are two quotes from the abstract: " The

concentration of total lipids, triglycerides, (LDL+VLDL)-cholesterol,

thiobarbituric acid-reactive substances (TBARS) and reduced

glutathione were increased in the plasma of mice fed the COCO diet " .

And: " These results indicate that the COCO diet, high in saturated

fatty acids, alters the lipid metabolism and AA turnover of

peritoneal macrophages in female mice and also produces a significant

degree of oxidative stress. "

" Effect of dietary fat saturation on lipid metabolism, arachidonic

acid turnover and peritoneal macrophage oxidative stress in mice.

Oliveros LB, Videla AM, Gimenez MS. "

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Study #10 used coconut oil, soybean oil, or coconut oil + EPA to see

whether EPA could attenuate the effects of chemically induced

cognitive impairment. The abstract says soybean oil did not help,

EPA did help and does not say what the effect of the coconut oil

was. (Obviously if it had been benefical they would have said so, so

I think we can assume it was not helpful).

" Omega-3 fatty acid ethyl-eicosapentaenoate, but not soybean oil,

attenuates memory impairment induced by central IL-1beta

administration.

Song C, Horrobin D. "

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So, among the first ten studies in an (unbiased) list derived from

a " coconut oil " search of Pubmed, there does not seem to be a single

one that indicates health **benefits** attributed to coconut oil.

And there are a few which suggest possibly serious problems with

coconut oil (high lipids; high-fat diet induced oxidative stress;

similar lipid effects as lard; inferior performance of young pigs

compared with linseed oil; deficiency of essential fats compared with

soybean oil; inferior to EPA in attenuating cognitive

impairment; ............... ).

By all means check this for yourself. And even check out the second

ten, if you like, to see if you find the ratio of positive/negative

better than in the first ten. And if you do, please post your

conclusions here.

After doing this exercise I am going to continue to avoid coconut

products. I had not been avoiding them 'like the plague' previously,

but I think I will be from here on. If in the future I find LOTS of

studies (not just one or two) from credible sources - say the Nurses'

Health Study; the Physicians Health Study; the Iowa Women's Health

Study; or whatever, that show appreciable benefits then I will begin

to become more open minded about coconut oil. But I doubt that will

be any time soon, or ever.

Naturally no one needs to pay any attention to my beliefs. We are

all free agents here.

All FWIW.

Rodney.