Plant vs Animal ALA & Prostate Cancer

[Guest guest]

I dont know if this has been posted before but came across it and found it relevant. The following study showed a directly proportional relationship between ALA intake and advanced prostate cancer risk. ALA from non-animal sources (at intakes much < 1% of total calories; 2.5 g of ALA from 2 Tbsp of ground flax in a 2000-cal diet would provide 1.1% of total energy) was reported to have an even greater impact on advanced prostate cancer risk than ALA from animal sources. Full text access is free at the AJCN site. Am J Clin Nutr 2004;80:204 –16. ABSTRACTBackground: Laboratory studies have shown that n-3 fatty acidsinhibit and n-6 fatty acids stimulate prostate tumor growth, butwhether the dietary intake of these fatty acids affects prostate cancerrisk in humans remains unclear. Objective: We prospectively evaluated the association betweenintakes of alpha-linolenic (ALA; 18:3n-3) , eicosapentaenoic (EPA;20:5n-3), docosahexaenoic (DHA; 22:6n-3), linoleic (LA; 18:2n-6), and arachidonic (AA; 20:4n-6) acids and prostate cancerrisk. Design: A cohort of 47 866 US men aged 40–75 y with no cancerhistory in 1986 was followed for 14 y. Results: During follow-up, 2965 new cases of total prostate cancerwere ascertained, 448 of which were advanced prostate cancer.ALAintake was unrelated to the risk of total prostate cancer. In contrast,the multivariate relative risks (RRs) of advanced prostate cancerfrom comparisons of extreme quintiles of ALA from nonanimalsources and ALA from meat and dairy sources were 2.02 (95% CI:1.35, 3.03) and 1.53 (0.88, 2.66), respectively. EPA and DHA intakeswere related to lower prostate cancer risk. The multivariateRRs of total and advanced prostate cancer from comparisons ofextreme quintiles of the combination of EPA and DHA were 0.89(0.77, 1.04) and 0.74 (0.49, 1.08), respectively. LA and AA intakeswere unrelated to the risk of prostate cancer. The multivariate RR ofadvanced prostate cancer from a comparison of extreme quintiles ofthe ratio of LA to ALA was 0.62 (0.45, 0.86). Conclusions: Increased dietary intakes of ALA may increase therisk of advanced prostate cancer. In contrast, EPA and DHA intakesmay reduce the risk of total and advanced prostate cancer.

[Guest guest]

Jeff Novick posted the study below. The positive features of ALA and in particular flax have been expounded upon many times. Would anyone care to comment if the study is just the odd one showing the opposite point of view or is there a reason for quitting or moderating flax intake....? There was a discussion a couple of months ago of monos vs polys, but I don't find anything on ALAs in the support group lists (maybe I havn't looked long enough back). // Ulf

Plant vs Animal ALA & Prostate Cancer

Posted by: "Jeff Novick" chefjeff40@... chefjeff40

Fri Mar 2, 2007 2:59 am (PST)

I dont know if this has been posted before but came across it and found it relevant.The following study showed a directly proportional relationship between ALA intake and advanced prostate cancer risk. ALA from non-animal sources (at intakes much < 1% of total calories; 2.5 g of ALA from 2 Tbsp of ground flax in a 2000-cal diet would provide 1.1% of total energy) was reported to have an even greater impact on advanced prostate cancer risk than ALA from animal sources. Full text access is free at the AJCN site.Am J Clin Nutr 2004;80:204 –16.ABSTRACTBackground: Laboratory studies have shown that n-3 fatty acidsinhibit and n-6 fatty acids stimulate prostate tumor growth, butwhether the dietary intake of these fatty acids affects prostate cancerrisk in humans remains unclear.Objective: We prospectively evaluated the association betweenintakes of alpha-linolenic (ALA; 18:3n-3) , eicosapentaenoic (EPA;20:5n-3), docosahexaenoic (DHA; 22:6n-3), linoleic (LA; 18:2n-6), and arachidonic (AA; 20:4n-6) acids and prostate cancerrisk.Design: A cohort of 47 866 US men aged 40–75 y with no cancerhistory in 1986 was followed for 14 y.Results: During follow-up, 2965 new cases of total prostate cancerwere ascertained, 448 of which were advanced prostate cancer.ALAintake was unrelated to the risk of total prostate cancer. In contrast,the multivariate relative risks (RRs) of advanced prostate cancerfrom comparisons of extreme quintiles of ALA from nonanimalsources and ALA from meat and dairy sources were 2.02 (95% CI:1.35, 3.03) and 1.53 (0.88, 2.66), respectively. EPA and DHA intakeswere related to lower prostate cancer risk. The multivariateRRs of total and advanced prostate cancer from comparisons ofextreme quintiles of the combination of EPA and DHA were 0.89(0.77, 1.04) and 0.74 (0.49, 1.08), respectively. LA and AA intakeswere unrelated to the risk of prostate cancer. The multivariate RR ofadvanced prostate cancer from a comparison of extreme quintiles ofthe ratio of LA to ALA was 0.62 (0.45, 0.86).Conclusions: Increased dietary intakes of ALA may increase therisk of advanced prostate cancer. In contrast, EPA and DHA intakesmay reduce the risk of total and advanced prostate cancer.

[Guest guest]

Hi Ulf:

There have now been several studies which have shown a connection

between ALA and prostate cancer. Particularly metastatic prostate

cancer. There have been a number of posts on this here the past

~three years. And I have speculated that it may be the presence of

aflatoxin (which is known to be associated with prostate cancer) in

some sources of ALA that is responsible. But this is purely

speculation on my part.

This could explain the fact that plant products appear to be worse

than animal sources. Because when the animal consumes the aflatoxin

source the amount in the meat or milk may be diluted compared with

that when a human consumes the affected plant directly.

It seems to me the science is far from definitive about exactly what

is going on here. But the connection does appear to be confirmed.

In general ALA appears to be a marker for something that causes

prostate cancer. But that does not necessarily means that all

sources of ALA cause prostate cancer. So we each have to try to make

our own best judgments about this in the absence of complete

information.

Rodney.

>

> Calorie Restriction/Optimum NutritionJeff Novick posted the study

below. The positive features of ALA and in particular flax have been

expounded upon many times. Would anyone care to comment if the study

is just the odd one showing the opposite point of view or is there a

reason for quitting or moderating flax intake....? There was a

discussion a couple of months ago of monos vs polys, but I don't find

anything on ALAs in the support group lists (maybe I havn't looked

long enough back). // Ulf

>

> Plant vs Animal ALA & Prostate Cancer

> Posted by: " Jeff Novick " chefjeff40@... chefjeff40

> Fri Mar 2, 2007 2:59 am (PST)

> I dont know if this has been posted before but came across it and

found it relevant.

>

> The following study showed a directly proportional relationship

> between ALA intake and advanced prostate cancer risk. ALA from

> non-animal sources (at intakes much < 1% of total calories; 2.5 g

of

> ALA from 2 Tbsp of ground flax in a 2000-cal diet would provide

1.1% of

> total energy) was reported to have an even greater impact on

advanced

> prostate cancer risk than ALA from animal sources.

>

> Full text access is free at the AJCN site.

>

> Am J Clin Nutr 2004;80:204 -16.

>

> ABSTRACT

> Background: Laboratory studies have shown that n-3 fatty acids

> inhibit and n-6 fatty acids stimulate prostate tumor growth, but

> whether the dietary intake of these fatty acids affects prostate

cancer

> risk in humans remains unclear.

>

> Objective: We prospectively evaluated the association between

> intakes of alpha-linolenic (ALA; 18:3n-3) , eicosapentaenoic (EPA;

> 20:5n-3), docosahexaenoic (DHA; 22:6n-3), linoleic (LA; 18:

> 2n-6), and arachidonic (AA; 20:4n-6) acids and prostate cancer

> risk.

>

> Design: A cohort of 47 866 US men aged 40-75 y with no cancer

> history in 1986 was followed for 14 y.

>

> Results: During follow-up, 2965 new cases of total prostate cancer

> were ascertained, 448 of which were advanced prostate cancer.ALA

> intake was unrelated to the risk of total prostate cancer. In

contrast,

> the multivariate relative risks (RRs) of advanced prostate cancer

> from comparisons of extreme quintiles of ALA from nonanimal

> sources and ALA from meat and dairy sources were 2.02 (95% CI:

> 1.35, 3.03) and 1.53 (0.88, 2.66), respectively. EPA and DHA intakes

> were related to lower prostate cancer risk. The multivariate

> RRs of total and advanced prostate cancer from comparisons of

> extreme quintiles of the combination of EPA and DHA were 0.89

> (0.77, 1.04) and 0.74 (0.49, 1.08), respectively. LA and AA intakes

> were unrelated to the risk of prostate cancer. The multivariate RR

of

> advanced prostate cancer from a comparison of extreme quintiles of

> the ratio of LA to ALA was 0.62 (0.45, 0.86).

>

> Conclusions: Increased dietary intakes of ALA may increase the

> risk of advanced prostate cancer. In contrast, EPA and DHA intakes

> may reduce the risk of total and advanced prostate cancer.

>

[Guest guest]

For those that have not actually read the study, and in light of your

comment below concerning a connection between ALA and prostate

cancer, I think that it's important to point out that the study

found " ALA intake was unrelated to the risk of total prostate

cancers. "

-Dave

" Rodney " <perspect1111@...> wrote:

>

> Hi Ulf:

>

> There have now been several studies which have shown a connection

> between ALA and prostate cancer. Particularly metastatic prostate

> cancer. There have been a number of posts on this here the past

> ~three years. And I have speculated that it may be the presence of

> aflatoxin (which is known to be associated with prostate cancer) in

> some sources of ALA that is responsible. But this is purely

> speculation on my part.

>

> This could explain the fact that plant products appear to be worse

> than animal sources. Because when the animal consumes the

aflatoxin

> source the amount in the meat or milk may be diluted compared with

> that when a human consumes the affected plant directly.

>

> It seems to me the science is far from definitive about exactly

what

> is going on here. But the connection does appear to be confirmed.

> In general ALA appears to be a marker for something that causes

> prostate cancer. But that does not necessarily means that all

> sources of ALA cause prostate cancer. So we each have to try to

make

> our own best judgments about this in the absence of complete

> information.

>

> Rodney.

>

>

> >

> > Calorie Restriction/Optimum NutritionJeff Novick posted the study

> below. The positive features of ALA and in particular flax have

been

> expounded upon many times. Would anyone care to comment if the

study

> is just the odd one showing the opposite point of view or is there

a

> reason for quitting or moderating flax intake....? There was a

> discussion a couple of months ago of monos vs polys, but I don't

find

> anything on ALAs in the support group lists (maybe I havn't looked

> long enough back). // Ulf

> >

> > Plant vs Animal ALA & Prostate Cancer

> > Posted by: " Jeff Novick " chefjeff40@ chefjeff40

> > Fri Mar 2, 2007 2:59 am (PST)

> > I dont know if this has been posted before but came across it and

> found it relevant.

> >

> > The following study showed a directly proportional relationship

> > between ALA intake and advanced prostate cancer risk. ALA from

> > non-animal sources (at intakes much < 1% of total calories; 2.5 g

> of

> > ALA from 2 Tbsp of ground flax in a 2000-cal diet would provide

> 1.1% of

> > total energy) was reported to have an even greater impact on

> advanced

> > prostate cancer risk than ALA from animal sources.

> >

> > Full text access is free at the AJCN site.

> >

> > Am J Clin Nutr 2004;80:204 -16.

> >

> > ABSTRACT

> > Background: Laboratory studies have shown that n-3 fatty acids

> > inhibit and n-6 fatty acids stimulate prostate tumor growth, but

> > whether the dietary intake of these fatty acids affects prostate

> cancer

> > risk in humans remains unclear.

> >

> > Objective: We prospectively evaluated the association between

> > intakes of alpha-linolenic (ALA; 18:3n-3) , eicosapentaenoic (EPA;

> > 20:5n-3), docosahexaenoic (DHA; 22:6n-3), linoleic (LA; 18:

> > 2n-6), and arachidonic (AA; 20:4n-6) acids and prostate cancer

> > risk.

> >

> > Design: A cohort of 47 866 US men aged 40-75 y with no cancer

> > history in 1986 was followed for 14 y.

> >

> > Results: During follow-up, 2965 new cases of total prostate cancer

> > were ascertained, 448 of which were advanced prostate cancer.ALA

> > intake was unrelated to the risk of total prostate cancer. In

> contrast,

> > the multivariate relative risks (RRs) of advanced prostate cancer

> > from comparisons of extreme quintiles of ALA from nonanimal

> > sources and ALA from meat and dairy sources were 2.02 (95% CI:

> > 1.35, 3.03) and 1.53 (0.88, 2.66), respectively. EPA and DHA

intakes

> > were related to lower prostate cancer risk. The multivariate

> > RRs of total and advanced prostate cancer from comparisons of

> > extreme quintiles of the combination of EPA and DHA were 0.89

> > (0.77, 1.04) and 0.74 (0.49, 1.08), respectively. LA and AA

intakes

> > were unrelated to the risk of prostate cancer. The multivariate

RR

> of

> > advanced prostate cancer from a comparison of extreme quintiles of

> > the ratio of LA to ALA was 0.62 (0.45, 0.86).

> >

> > Conclusions: Increased dietary intakes of ALA may increase the

> > risk of advanced prostate cancer. In contrast, EPA and DHA intakes

> > may reduce the risk of total and advanced prostate cancer.

> >

>

[Guest guest]

Hi Dave:

This has all been covered here previously, more than once. It is in

the archives. Or, those interested could search elsewhere for newer

papers and post their findings. There have, as noted, been several

studies that have shown varying types of links between ALA and

prostate cancer. It is pretty much standard procedure for studies

done by different investigators, with different methodologies and on

different population groups to come to different conclusions. And in

addition different people are persuaded by different kinds of

evidence.

But if you are aware of ANY studies that found *ALA* protects against

prostate cancer please post them, because I have not seen them.

Clearly, it is metastatic prostate cancer that we REALLY need to

avoid. The logic behind that paper seems to me to be that, while

prostate cancer may get initiated for reasons other than ALA, once it

is initiated (and prostate cancer is very nearly as common in males

as breast cancer is in females) consuming appreciable amounts of ALA

will more than double the likelihood it will metastasize.

But if you have a different interpretation please post it. As with

just about everything else, the evidence is not yet conclusive.

I generally avoid ALA, and get the oils I think I need from fish

sources. But if persuasive evidence appears that suggests something

different I will be happy to change that. When I become aware of

it.

The principal (and sizeable) benefit of ALA of which I am aware is in

prevention of CVD. But it is doubtful that adding ALA to the diet of

someone established on CRON will make any material difference in that

respect.

Rodney.

> > >

> > > Calorie Restriction/Optimum NutritionJeff Novick posted the

study

> > below. The positive features of ALA and in particular flax have

> been

> > expounded upon many times. Would anyone care to comment if the

> study

> > is just the odd one showing the opposite point of view or is

there

> a

> > reason for quitting or moderating flax intake....? There was a

> > discussion a couple of months ago of monos vs polys, but I don't

> find

> > anything on ALAs in the support group lists (maybe I havn't

looked

> > long enough back). // Ulf

> > >

> > > Plant vs Animal ALA & Prostate Cancer

> > > Posted by: " Jeff Novick " chefjeff40@ chefjeff40

> > > Fri Mar 2, 2007 2:59 am (PST)

> > > I dont know if this has been posted before but came across it

and

> > found it relevant.

> > >

> > > The following study showed a directly proportional relationship

> > > between ALA intake and advanced prostate cancer risk. ALA from

> > > non-animal sources (at intakes much < 1% of total calories; 2.5

g

> > of

> > > ALA from 2 Tbsp of ground flax in a 2000-cal diet would provide

> > 1.1% of

> > > total energy) was reported to have an even greater impact on

> > advanced

> > > prostate cancer risk than ALA from animal sources.

> > >

> > > Full text access is free at the AJCN site.

> > >

> > > Am J Clin Nutr 2004;80:204 -16.

> > >

> > > ABSTRACT

> > > Background: Laboratory studies have shown that n-3 fatty acids

> > > inhibit and n-6 fatty acids stimulate prostate tumor growth, but

> > > whether the dietary intake of these fatty acids affects

prostate

> > cancer

> > > risk in humans remains unclear.

> > >

> > > Objective: We prospectively evaluated the association between

> > > intakes of alpha-linolenic (ALA; 18:3n-3) , eicosapentaenoic

(EPA;

> > > 20:5n-3), docosahexaenoic (DHA; 22:6n-3), linoleic (LA; 18:

> > > 2n-6), and arachidonic (AA; 20:4n-6) acids and prostate cancer

> > > risk.

> > >

> > > Design: A cohort of 47 866 US men aged 40-75 y with no cancer

> > > history in 1986 was followed for 14 y.

> > >

> > > Results: During follow-up, 2965 new cases of total prostate

cancer

> > > were ascertained, 448 of which were advanced prostate cancer.ALA

> > > intake was unrelated to the risk of total prostate cancer. In

> > contrast,

> > > the multivariate relative risks (RRs) of advanced prostate

cancer

> > > from comparisons of extreme quintiles of ALA from nonanimal

> > > sources and ALA from meat and dairy sources were 2.02 (95% CI:

> > > 1.35, 3.03) and 1.53 (0.88, 2.66), respectively. EPA and DHA

> intakes

> > > were related to lower prostate cancer risk. The multivariate

> > > RRs of total and advanced prostate cancer from comparisons of

> > > extreme quintiles of the combination of EPA and DHA were 0.89

> > > (0.77, 1.04) and 0.74 (0.49, 1.08), respectively. LA and AA

> intakes

> > > were unrelated to the risk of prostate cancer. The multivariate

> RR

> > of

> > > advanced prostate cancer from a comparison of extreme quintiles

of

> > > the ratio of LA to ALA was 0.62 (0.45, 0.86).

> > >

> > > Conclusions: Increased dietary intakes of ALA may increase the

> > > risk of advanced prostate cancer. In contrast, EPA and DHA

intakes

> > > may reduce the risk of total and advanced prostate cancer.

> > >

> >

>