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Trans Fats in Blood Samples And 3X Risk of CHD - Correlation

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Jbuch - 28 Mar 2007 14:43 GMT
Harvard School of Public Health (HSPH) Study using "Nurse's Health
Study" blood specimens from 1989 and 1990.

Press Release Here:

http://www.sciencedaily.com/releases/2007/03/070327144449.htm

The researchers, led by Hu and lead author Qi Sun, a graduate research
assistant at HSPH, set out to test the assumption that higher trans
fatty acid levels in erythrocytes—red blood cells—were associated with a
higher risk of heart disease among U.S. women. Blood samples collected
in 1989 and 1990 from 32,826 participants in the Brigham and Women’s
Hospital-based Nurses’ Health Study were examined. During six years of
follow-up, 166 cases of CHD were diagnosed and matched with 327 controls
for age, smoking status, fasting status and date of blood drawing.

After adjusting for age, smoking status and other dietary and lifestyle
cardiovascular risk factors, the researchers found that a higher level
of trans fatty acids in red blood cells was associated with an elevated
risk of CHD. The risk among women in the top quartile of trans fat
levels was triple that of the lowest quartile. “Positive associations
have been shown in earlier studies based on dietary data provided by the
participants, but the use of biomarkers of trans fatty acids is believed
to be more reliable than self-reports. This is probably the reason why
we see an even stronger association between blood levels of trans fat
and risk of CHD in this study,” said Sun.

“These data provide further justifications for current efforts to remove
trans fat from foods and restaurant meals,” said Hu. “Trans fat intake
in the U.S. is still high. Reducing trans fat intake should remain an
important public health priority.”

The study was supported by the National Institutes of Health.
Cubit - 28 Mar 2007 15:53 GMT
Great post.

> Harvard School of Public Health (HSPH) Study using "Nurse's Health Study"
> blood specimens from 1989 and 1990.
[quoted text clipped - 29 lines]
>
> The study was supported by the National Institutes of Health.
monty1945@lycos.com - 29 Mar 2007 03:34 GMT
The usual stuff.  Think about what was actually found.  First of all,
"triple" can mean there were 3 cases out of a million instead of 1
case in a million.  Always look at the actual numbers.  Instead, they
always talk in terms of "100% more likely," or something similar,
which could mean 2 cases instead of 1.

However, let's say their findings appear to be compelling to most
people.  They found that more trans fatty acids in the blood to
correlate with a higher incidence of what they define as "heart
disease."  Did these people live shorter lives, however?  They don't
tell us.  In many cases, the studies are too short or don't determine
this even when they can.  Instead, they try to correlate markers with
what they define as a particular "disease," and if people die of
something else, you don't hear about it.

Since trans fatty acids contain double bonds, which can generate free
radicals and cause LDL to get oxidized and also come from food that
has been stripped of natural antioxidant cover, this is not a
surprising result, if it is a result that is consistent with the
general claim they are making.  Yet did they control for antioxidants
in the diet?  The problem is that there is no reason to think that a
trans fatty acid is worse than a polyunsaturated fatty acid with the
same number of unsaturated bonds.  In fact, trans fatty acids may be
less susceptible to lipid peroxidation than "natural" cis unsaturated
fatty acids.  Again, the difference is probably that there are less
antioxidants in the diets of those who eat a significant amount of
TFAs as opposed to those who eat a significant amount of "natural"
UFAs.

>From the report you cite, it does not appear that antioxidant intake
was controlled, and possibly overall fat consumption may not have been
controlled either (and it also may be that those who ate more TFAs ate
more oxidized cholesterol as well).  In fact, if I could bet money on
it, I would bet that those with the most TFAs in their blood were
eating much less healthy diets overall.  However, the people who
conduct these studies hardly ever control for something like oxidized
cholesterol, though they may indeed control for cholesterol (meaning
that they don't determine if it is oxidized or not).  To them, dietary
cholesterol is all the same, all unhealthy.  However, the evidence is
now clear (even if these people are not aware of it), and so their
underlying assumptions doom the study to meaninglessness (or worse,
many can be mislead into eating an unhealthy diet by such "studies").
mattlb@angelfire.com - 29 Mar 2007 13:38 GMT
On Mar 29, 3:34 am, monty1...@lycos.com wrote:
> The usual stuff.  Think about what was actually found.  First of all,
> "triple" can mean there were 3 cases out of a million instead of 1
> case in a million.  Always look at the actual numbers.

Like the 166 that they quote you mean.

> However, let's say their findings appear to be compelling to most
> people.  They found that more trans fatty acids in the blood to
> correlate with a higher incidence of what they define as "heart
> disease."  Did these people live shorter lives, however?  They don't
> tell us.

They weren't trying to assess that. It's already known that heart
disease kills people, they're just looking for whether trans fatty
acids levels in blood cells are associated with it. Since trans fatty
acids are an abnormal consituient of the body a correlation with CHD
is more compelling than if it was with something naturally occurring.

> In many cases, the studies are too short or don't determine
> this even when they can.  Instead, they try to correlate markers with
> what they define as a particular "disease," and if people die of
> something else, you don't hear about it.

Because it's not relevant.

> Yet did they control for antioxidants
> in the diet?

They weren't looking at the effects of antioxidants, they were doing a
prospective study on whether there's a relationship between trans fat
levels and heart disease.

> The problem is that there is no reason to think that a
> trans fatty acid is worse than a polyunsaturated fatty acid with the
> same number of unsaturated bonds.

Yes there is, but you lack the knowledge and understanding to know
why. Try this paper on for size, but it will only make your
backpedalling go all the faster.

"Consumption of trans fatty acids is related to plasma biomarkers of
inflammation and endothelial dysfunction."
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?itool=abstractplus&db=pubmed&cmd=R
etrieve&dopt=abstractplus&list_uids=15735094


> In fact, trans fatty acids may be
> less susceptible to lipid peroxidation than "natural" cis unsaturated
> fatty acids.

On what basis do you make that claim?

>From the report you cite, it does not appear that antioxidant intake
> was controlled, and possibly overall fat consumption may not have been
> controlled either (and it also may be that those who ate more TFAs ate
> more oxidized cholesterol as well).

"After adjusting for age, smoking status and other dietary and
lifestyle
cardiovascular risk factors "

MattLB
deke - 29 Mar 2007 17:15 GMT
The guy is a complete idiot so please don't try to use intelligent
dialog with him.  

Trans-fat kills.   Pure and simple.   And Anti Oxidants has nothing
to do with it.

>On Mar 29, 3:34 am, monty1...@lycos.com wrote:
>> The usual stuff.  Think about what was actually found.  First of all,
[quoted text clipped - 57 lines]
>
>MattLB
monty1945@lycos.com - 29 Mar 2007 22:05 GMT
"During six years of follow-up, 166 cases of CHD were diagnosed and
matched with 327 controls
for age, smoking status, fasting status and date of blood drawing."

This is not controlled properly, though it might pass for "science"
these days.  They took the people who developed "CHD" and then
compared them to people without CHD, who they deemed to be similar.
For all we know, there could have been a large number of people with
high trans fatty acid levels and no CHD.  If you want to "believe," be
my guest.  However, if you want to claim that an unsaturated bond is
healthy in a configuratiion that is more likely to be degraded by free
radicals, whereas another unsaturated bond is very uhealthy, even
though it is more resistant, you are writing yourself a fairly tale.

Notice how MattLB does not address my point.  Where does it say that
they accounted for oxidized cholesterol or antioxidant intake?  In
fact, not all the naturally-occurring antioxidants contained in
"natural" foods are even known - he is so wrong it is laughable!

If you disagree, my offer is still open to anyone with several hundred
dollars to spare:

We will feed two dozen adult rats a diet of 30% fresh coconut oil (my
choice) or 30% canola and fish oil.  No added antioxidants, just a
basic vitamin/mineral supplement.  Otherwise, they get the same food,
with no other source of fat.  All else will be equal.  Then if the
coconut fed rats live to be the same age or longer, you will pay for
all expenses, whereas I will if the coconut fed ones live what is
considered to be statistically-significant shorter lives.

Note that as I said, I don't necessarily disagree with their findings,
but it is the mechanism that makes no sense.  There is no reason to
blame a trans fatty acid unless you also blame an unsaturated fatty
acid with the same number of bonds.  Trans fatty acids are naturally-
occurring, but in small amounts, just as most humans ate diets very
low in PUFAs until recently.  If you disagree, simple and inexpensive
experiments that do control for these factors can be done.  Also, you
might want to take a look at what Shils and Young have to say about
trans fatty acids in their massive nutrition textbook (written for
professionals).  They point out that fish oil is much worse in the
atherosclerotic context.  This was documented decades ago in
experiments that did control properly.  Nother MattLB claims can
change that fact.  Get the book and see for yourself.

Also note that I am willing to debate anyone on this issue, provided
that a mutally-acceptable person be appointed as moderator.  Calling
someone you disagree with on a scientific issue an "idiot" is clearly
not going to resolve anything.
MattLB - 30 Mar 2007 13:15 GMT
On Mar 29, 10:05 pm, monty1...@lycos.com wrote:
> "During six years of follow-up, 166 cases of CHD were diagnosed and
> matched with 327 controls
> for age, smoking status, fasting status and date of blood drawing."

> This is not controlled properly, though it might pass for "science"
> these days.

What's the problem with the control group? The only known a priori
difference is the presence of CHD. If you then measure trans fat
levels and the ones with CHD have the highest it's a clear
correlation.

> They took the people who developed "CHD" and then
> compared them to people without CHD, who they deemed to be similar.

Since it hasn't been published yet, you don't actually know what they
did.

> For all we know, there could have been a large number of people with
> high trans fatty acid levels and no CHD.

We do know. They found a strong correlation between trans fat and CHD,
therefore there can't have been "a large number" with the exact
opposite.

>  If you want to "believe," be
> my guest.

If you want to dismiss the data and stick to your faith-based view, be
my guest. Just stop posting your fantasies as the scientific truth.

>  However, if you want to claim that an unsaturated bond is
> healthy in a configuratiion that is more likely to be degraded by free
> radicals, whereas another unsaturated bond is very uhealthy, even
> though it is more resistant, you are writing yourself a fairly tale.

Your claim of trans double bonds being more resistant has never been
backed up by a citation, but feel free to give one, otherwise you're
the one spinning the fairytale.

> Notice how MattLB does not address my point.  Where does it say that
> they accounted for oxidized cholesterol or antioxidant intake?

I did address your point: "They weren't looking at the effects of
antioxidants, they were doing a prospective study on whether there's a
relationship between trans fat
levels and heart disease. "

Your argument may be that everyone who had high trans fat also had low
antioxidants/oxidized cholesterol and that's what's really to blame,
but you've no evidence for that, whereas there is evidence for high
trans fat being associated with CHD.

> In fact, not all the naturally-occurring antioxidants contained in
> "natural" foods are even known

Equally irrelevant.

> Note that as I said, I don't necessarily disagree with their findings,
> but it is the mechanism that makes no sense.

What mechanism are you talking about? Their study isn't looking for a
mechanism, just a correlation.

> There is no reason to
> blame a trans fatty acid unless you also blame an unsaturated fatty
> acid with the same number of bonds.

For general lipid peroxidation that's true, but physiologically it's
naive and untrue.

>  Trans fatty acids are naturally-
> occurring,

Not in human tissues. They have to come from the diet - that's why
they're such a useful measurement when relating disease to diet.

> but in small amounts, just as most humans ate diets very
> low in PUFAs until recently.

Obviously not true for any seaside communities.

> might want to take a look at what Shils and Young have to say about
> trans fatty acids in their massive nutrition textbook (written for
> professionals).  They point out that fish oil is much worse in the
> atherosclerotic context.  This was documented decades ago in
> experiments that did control properly.

But would have had inferior measuring techniques. Also trans fatty
acids weren't prevalent decades ago, nor was the oxLDL mechanism for
atherosclerosis known.

>  Nother MattLB claims can
> change that fact.  Get the book and see for yourself.

Which edition are you talking about?

MattLB
Ron Peterson - 30 Mar 2007 05:54 GMT
On Mar 29, 7:38 am, mat...@angelfire.com wrote:

> "Consumption of trans fatty acids is related to plasma biomarkers of
> inflammation and endothelial dysfunction."http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?itool=abstractplus&db=p...

And, a related link states:
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?itool=abstractplus&db=pubmed&cmd=R
etrieve&dopt=abstractplus&list_uids=15226473

"In conclusion, this study suggests that dietary (n-3) fatty acids are
associated with levels of these biomarkers reflecting lower levels of
inflammation and endothelial activation, which might explain in part
the effect of these fatty acids in preventing cardiovascular disease."

--
   Ron
Ron Peterson - 28 Mar 2007 23:13 GMT
> Harvard School of Public Health (HSPH) Study using "Nurse's Health
> Study" blood specimens from 1989 and 1990.

> Press Release Here:

> http://www.sciencedaily.com/releases/2007/03/070327144449.htm

Science Daily has this version of the news release:

Science Daily - High consumption of trans fat, found mainly in
partially hydrogenated vegetable oils and widely used by the food
industry, has been linked to an increased risk of coronary heart
disease (CHD). New York and Philadelphia have passed measures
eliminating its use in restaurants, and other cities are considering
similar bans. A new study from the Harvard School of Public Health
(HSPH) provides the strongest association to date between trans fat
and heart disease. It found that women in the U.S. with the highest
levels of trans fat in their blood had three times the risk of CHD as
those with the lowest levels. The study  will appear in the April 10,
2007 print issue of Circulation: Journal of the American Heart
Association.

...

After adjusting for age, smoking status and other dietary and
lifestyle cardiovascular risk factors, the researchers found that a
higher level of trans fatty acids in red blood cells was associated
with an elevated risk of CHD. The risk among women in the top quartile
of trans fat levels was triple that of the lowest quartile. "Positive
associations have been shown in earlier studies based on dietary data
provided by the participants, but the use of biomarkers of trans fatty
acids is believed to be more reliable than self-reports. This is
probably the reason why we see an even stronger association between
blood levels of trans fat and risk of CHD in this study," said Sun.
"These data provide further justifications for current efforts to
remove trans fat from foods and restaurant meals," said Hu. "Trans fat
intake in the U.S. is still high. Reducing trans fat intake should
remain an important public health priority."
The study was supported by the National Institutes of Health.
"A Prospective Study of Trans Fatty Acids in Erythrocytes and Risk of
Coronary Heart Disease," Qi Sun, Jing Ma, Hannia Campos, Susan E.
Hankinson, JoAnn E. Manson, Meir J. Stampfer, Kathryn M. Rexrode,
Walter C. Willett, Frank B. Hu, Circulation, April 10, 2007.

--
  Ron
 
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