Re: Polyunsaturated Fats and Cancer

[Guest guest]

PS: If anyone can shoot down any or all of the arguments in the link

contained in my post #14275 on polyunsaturated fats and cancer, I

will be more than delighted to hear it. I notice that the author

appears to be a leading member of the 'cholesterol skeptics'

group .......... Uh oh!

Rodney.

--- In , " Rodney " <perspect1111@y...>

wrote:

> Hi folks:

>

> Working on the basis that CR fully resolves the heart disease issue

> for the (vast?) majority of people; and therefore that issues

related

> to diseases other than heart disease should be of more interest to

> most of us here ............ here is something on the

relationship

> between polyunsaturated fats and cancer.

>

> I realize this is not a '.edu' source, and therefore its

reliability

> is uncertain. Read it for what you can get out of it. It seem to

me

> to raise some interesting issues about the well known tendency for

> (at least some) polyunsaturated fats to promote cancer.

>

> http://www.second-opinions.co.uk/fats_and_cancer.html

>

> http://snipurl.com/8h89

>

> And perhaps this a more important issue for us than the benefits,

or

> otherwise, of oils for heart disease.

>

> Rodney.

[Guest guest]

>>>>

From: " Rodney " <perspect1111@y...>

Date: Tue Aug 17, 2004 8:18 am

Subject: Re: Polyunsaturated Fats and Cancer

PS: If anyone can shoot down any or all of the arguments in the link

contained in my post #14275 on polyunsaturated fats and cancer, I

will be more than delighted to hear it. I notice that the author

appears to be a leading member of the 'cholesterol skeptics'

group .......... Uh oh!

Rodney.

> http://www.second-opinions.co.uk/fats_and_cancer.html

>>>>

Rodney,

Sometimes the search for truth leads you into unexpected places.

The second-opinions web site references the link that you

provided on your post #14274, but states ALL the information (you left

out the part about saturated fats) in the reference which is:

>>>

Polyunsaturated fats and breast cancer

A study of 61,471 women aged forty to seventy-six, conducted in

Sweden, looked into the relation of different fats and breast cancer.

The results were published in January 1998. This study found an

inverse association with monounsaturated fat and a positive

association with polyunsaturated fat. In other words, monounsaturated

fats protected against breast cancer and polyunsaturated fats

increased the risk. Saturated fats were neutral. (15)

15. Wolk A, et al. A Prospective Study of Association of

Monounsaturated Fat and Other Types of Fat With Risk of Breast Cancer.

Arch Intern Med. 1998; 158: 41-45

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=

Retrieve & db=PubMed & list_uids=9437377 & dopt=Abstract

>>>

Apparently, Barry Groves wrote this back in 18 September 2000. He

seems to do good research and articulate it cogently. He has a PhD in

nutrition. Just because you don't like his ideas, it does not mean

that he is not right. Classifying him as a " cholesterol skeptic " is

an ad hominem dig, but his peer-reviewed references provide support

for his position. To prove him wrong, you will need to refute all the

scientific work on which he bases his conclusions.

We are back to olive oil and lard!

Tony

[Guest guest]

Hi Tony:

Well if calling him a 'cholesterol skeptic' is an 'ad hominem dig'

then he is taking adhominem digs at himself, since **HE** on his

website says he is: " ...... currently a director of the Foundation

for Thymic Cancer Research, a founder member of the Fluoride Action

Network, a founder member of THINCS – The International Network of

Cholesterol Sceptics and an honorary member of the board of the

Weston A Price Foundation. "

I posted that link because I thought it might have some useful

information. But I was not prepared to read all his cited sources to

see if they supported the views he expressed. It is good to hear,

from someone who has read them (thanks), that they do.

Anyway, the point is that if heart disease is of relatively little

consequence to most of us here then information about fats and cancer

is stuff to which we should probably be paying attention.

Rodney.

> >>>>

> From: " Rodney " <perspect1111@y...>

> Date: Tue Aug 17, 2004 8:18 am

> Subject: Re: Polyunsaturated Fats and Cancer

> PS: If anyone can shoot down any or all of the arguments in the link

> contained in my post #14275 on polyunsaturated fats and cancer, I

> will be more than delighted to hear it. I notice that the author

> appears to be a leading member of the 'cholesterol skeptics'

> group .......... Uh oh!

> Rodney.

> > http://www.second-opinions.co.uk/fats_and_cancer.html

> >>>>

>

> Rodney,

>

> Sometimes the search for truth leads you into unexpected places.

> The second-opinions web site references the link that you

> provided on your post #14274, but states ALL the information (you

left

> out the part about saturated fats) in the reference which is:

>

> >>>

> Polyunsaturated fats and breast cancer

>

> A study of 61,471 women aged forty to seventy-six, conducted in

> Sweden, looked into the relation of different fats and breast

cancer.

> The results were published in January 1998. This study found an

> inverse association with monounsaturated fat and a positive

> association with polyunsaturated fat. In other words,

monounsaturated

> fats protected against breast cancer and polyunsaturated fats

> increased the risk. Saturated fats were neutral. (15)

>

> 15. Wolk A, et al. A Prospective Study of Association of

> Monounsaturated Fat and Other Types of Fat With Risk of Breast

Cancer.

> Arch Intern Med. 1998; 158: 41-45

>

> http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=

> Retrieve & db=PubMed & list_uids=9437377 & dopt=Abstract

> >>>

>

> Apparently, Barry Groves wrote this back in 18 September 2000. He

> seems to do good research and articulate it cogently. He has a PhD

in

> nutrition. Just because you don't like his ideas, it does not mean

> that he is not right. Classifying him as a " cholesterol skeptic " is

> an ad hominem dig, but his peer-reviewed references provide support

> for his position. To prove him wrong, you will need to refute all

the

> scientific work on which he bases his conclusions.

>

> We are back to olive oil and lard!

>

> Tony

[Guest guest]

As Francesca remarked, the second-opinions web site should be

discarded as a reference. Last August, I contacted Barry Groves, who

manages the second-opinions web site and criticized one of the

statements that he has on his web site:

>>

http://www.second-opinions.co.uk/vegetarian.html

Human milk contains the fatty acids needed for large brain development

– cow's milk does not. It is no coincidence that in relative

terms, our brain is some fifty times the size of a cow's.

>>

I told him that brain development is guided more by genetics than by

fatty acid composition of the foods that you eat, and that the fatty

acid ratios in cow and human milk are not that different according the

the Handbook of Chemistry and Physics. He never replied. Although he

claims that " all articles are fully supported by references from

peer-reviewed medical and scientific journals " , his thinking process

does not seem to be scientifically rigorous. He is also marketing a

book on low carb diet that he wrote, so he is not particularly

unbiased.

With regard to the question about whether polyunsaturated fats are

associated with cancer, here are two articles which found no risk or

reduced risk of cancer from polyunsaturated fatty acids, paticularly

for fish oil.

Tony

===

BMJ. 1995 Nov 11;311(7015):1251-4.

Fatty acid proportions in cholesterol esters and risk of premature

death from cancer in middle aged French men.

Zureik M, Ducimetiere P, Warnet JM, Orssaud G.

OBJECTIVE--To assess the association of proportions of fatty acids

in cholesterol esters with the risk of premature death from cancer in

middle aged men. DESIGN--Prospective cohort study. SETTING--Paris,

France. SUBJECTS--3277 working men aged 36-52 in 1981-5. MAIN OUTCOME

MEASURES--Cancer mortality during an average of 9.3 years of follow

up. RESULTS--59 men died of cancer during follow up. The age adjusted

relative risks for men in the highest thirds of the distribution of

the proportions of linoleic, palmitoleic, and oleic acid in

cholesterol esters as compared with those in the corresponding lowest

thirds were 0.16 (95% confidence interval 0.05 to 0.51), 3.39 (1.63 to

7.05), and 4.22 (1.95 to 9.12), respectively. Adjustment for and

stratification by smoking, alcohol consumption, serum cholesterol

concentration, and body mass index did not alter the results. At the

time of examination subjects with cancer had a lower intake of

polyunsaturated fats, assessed by 24 hour recall, than those without

cancer (13.2 v 17.4 g/day, P < 0.01). CONCLUSIONS--Monounsaturated and

polyunsaturated fatty acids of cholesterol esters are strong

biological markers that predict premature death from cancer in French

men. Consistently, intake of polyunsaturated fats did not seem to

increase the risk of death from cancer. The association of biological

markers of dietary fat intake with incidence of and mortality from

cancer should be investigated prospectively in other populations.

PMID: 7496232

===

Br J Cancer. 2003 Nov 3;89(9):1686-92

Opposing effects of dietary n-3 and n-6 fatty acids on mammary

carcinogenesis: The Singapore Chinese Health Study.

Gago-Dominguez M, Yuan JM, Sun CL, Lee HP, Yu MC.

We investigated the effects of individual fatty acids on breast

cancer in a prospective study of 35,298 Singapore Chinese women aged

45-74 years, who were enrolled during April 1993 to December 1998 (The

Singapore Chinese Health Study). At recruitment, each study subject

was administered, in-person, a validated, semiquantitative food

frequency questionnaire consisting of 165 food and beverage items. As

of December 31, 2000, 314 incident cases of breast cancer had

occurred. We used the regression methods to examine individual

fatty acids in relation to breast cancer risk, with adjustment for age

at baseline interview, year of interview, dialect group, level of

education, daily alcohol drinking, number of live births, age when

menstrual periods became regular, and family history of breast cancer.

Consumption of saturated, monounsaturated or polyunsaturated fat

overall was unrelated to risk. On the other hand, high levels of

dietary n-3 fatty acids from fish/shellfish (marine n-3 fatty acids)

were significantly associated with reduced risk. Relative to the

lowest quartile of intake, individuals in the higher three quartiles

exhibited a 26% reduction in risk (relative risk (RR)=0.74, 95%

confidence interval (CI)=0.58, 0.94)); RRs were similar across the top

three quartiles of intake (0.75, 0.75, 0.72, respectively). Overall,

there was no association between n-6 fatty acids and breast cancer

risk. However, among subjects who consumed low levels of marine n-3

fatty acids (lowest quartile of intake), a statistically significant

increase in risk was observed in individuals belonging to the highest

vs the lowest quartile of n-6 fatty acid consumption (RR=1.87, 95%

CI=1.06-3.27); the corresponding RR for advanced breast cancer was

2.45 (95% CI=1.20-4.97, P for trend=0.01). To our knowledge, these are

the first prospective findings linking the intake of marine n-3 fatty

acids to breast cancer protection.

PMID: 14583770

===

This provides a general overview of dietary fats and their effects on

health, not specifically about polyunsaturated fats:

Asia Pac J Clin Nutr. 2004 Aug;13(Suppl):S22.

Dietary fat quality: a nutritional epidemiologist's view.

Khor GL.

PMID: 15294485