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From: Enrico C on 23 Jan 2007 16:30
Do sat fat elevate cholesterol and CHD risk, regardless of total calories?


What do you make of this "Saturated fat debate"?
http://www.proteinpower.com/drmike/?p=345
(it's a pro protein site, but protein is not the issue here)

There you can read this letter published on the December issue of th
American Journal of Clinical Nutrition (AJCN) ?


LETTER TO THE EDITOR

Saturated fat does not affect blood cholesterol
Uffe Ravnskov
Magle Stora Kyrkogata 9
S-22350 Lund
Sweden

Dear Sir:

The most striking observation from the study by Krauss et al (1) is the
finding that a diet rich in saturated fatty acids (SFAs) results in a lower
or a steady state concentration of total and LDL cholesterol and an
increase in the concentration of HDL cholesterol, regardless of whether the
diet has a reduced energy content. Similar effects on blood lipids have
been observed in 4 weight-reducing trials with high intakes of SFAs
(2-5)(Table 1) and in many similar trials with unrestricted intakes of
SFAs.

[Table 1 goes here. I don't have enough technical know-how to copy it from
the paper. It is a summary of the above references 2-5 presenting data
showing the lack of cholesterol elevation brought about by dietary
saturated fat in doses of up to 50 percent of calories consumed.]

In 1973, Reiser (6) questioned the effects of SFA intake on serum
cholesterol. In a thorough review of the relevant experiments, he noted
several methodologic and interpretational errors. The most important errors
are probably the attribution of differences between SFAs and
polyunsaturated fatty acids to the former, when the effect could have been
due to the latter, and the use of vegetable oils saturated by hydrogenation
instead of natural SFAs.

A possible reason why the effects were more pronounced before weight
reduction than after weight reduction in the study by Krauss et al was the
difference in metabolism between the normal-weight and overweight subjects.
Cornier et al (7) recently found that total and LDL-cholesterol
concentrations decreased more with a low-carbohydrate than with a low-fat,
calorie-restricted diet. Interestingly, the overweight subjects with
reduced insulin sensitivity, but not those with normal insulin sensitivity,
had an increase in cholesterol with the low-fat diet but a decrease with
the low-carbohydrate diet. In both groups, the changes in lipids were more
beneficial with a low-carbohydrate diet than with a low-fat diet.
Therefore, the different lipid responses before and after weight reduction
in the study by Krauss et al may have been because the loss of weight may
have improved the participants' insulin sensitivity and thus their lipid
response.

Because the main reason for restricting the intake of SFAs in all official
guidelines is to change blood lipids, demonizing these nutrients seems
inappropriate. In his editorial, Katan (8) claims that high intakes of
unsaturated fatty acids reduce the risk of heart attacks, but his evidence
is based on a meta-analysis that had ignored 4 unsuccessful trials (9). Two
meta-analyses of all controlled clinical trials in which the only
intervention was a change in dietary fats found no effect on coronary or
total mortality (10).

ACKNOWLEDGMENTS

The author had no vested interest in the subject of this letter.

REFERENCES

Krauss RM, Blanche PJ, Rawlings RS, Fernstrom HS, Williams PT. Separate
effects of reduced carbohydrate intake and weight loss on atherogenic
dyslipidemia. Am J Clin Nutr 2006;83:1025–31.
Sondike SB, Copperman N, Jacobson MS. Effects of a low-carbohydrate diet on
weight loss and cardiovascular risk factor in overweight adolescents. J
Pediatr 2003;142:253–8.
Hays JH, DiSabatino A, Gorman RT, Vincent S, Stillabower ME. Effect of a
high saturated fat and no-starch diet on serum lipid subfractions in
patients with documented atherosclerotic cardiovascular disease. Mayo Clin
Proc 2003;78:1331–6.
Meckling KA, O'Sullivan C, Saari D. Comparison of a low-fat diet to a
low-carbohydrate diet on weight loss, body composition, and risk factors
for diabetes and cardiovascular disease in free-living, overweight men and
women. J Clin Endocrinol Metab 2004;89:2717–23.
Sharman MJ, Gomez AL, Kraemer WJ, Volek JS. Very low-carbohydrate and
low-fat diets affect fasting lipids and postprandial lipemia differently in
overweight men. J Nutr 2004;134:880–5.
Reiser R. Saturated fat in the diet and serum cholesterol concentration: a
critical examination of the literature. Am J Clin Nutr 1973;26:524–55.
Cornier MA, Donahoo WT, Pereira R, et al. Insulin sensitivity determines
the effectiveness of dietary macronutrient composition on weight loss in
obese women. Obes Res 2005;13:703–9.
Katan MB. Alternatives to low-fat diets. Am J Clin Nutr 2006;83:989–90.
Ravnskov U. The diet-heart idea is kept alive by selective citation. Rapid
response. BMJ 8. December 2003.
Ravnskov U. Diet-heart disease hypothesis is wishful thinking. BMJ
2002;324:238.
From: monty1945 on 23 Jan 2007 20:08
I've been working on this topic for several years now. What most of
the critics of the "lipid hypothesis" don't discuss is the role of
oxidation, which would actually support their arguments. For example,
there are studies of peoples who all have "high cholesterol" and eat
diets rich in saturated fatty acids (coconut products) but have no CHD
problems. Why? Because cholesterol around 200-200 is good, so long as
it is not oxidized. You can read all about this, along with citations
from the relevant evidence, at my free site:

http://groups.msn.com/TheScientificDebateForum-/

You can ask me questions in the forums there, if you have any.

From: Jim Chinnis on 23 Jan 2007 21:34
Enrico C <use_replyto_address(a)devils.com> wrote in part:

>Do sat fat elevate cholesterol and CHD risk, regardless of total calories?

I have searched for evidence that saturated fat increases CHD risk without
finding good evidence. I have gotten copies of most of the cited (old)
studies.
--
Jim Chinnis Warrenton, Virginia, USA jchinnis(a)alum.mit.edu
From: Ron Peterson on 24 Jan 2007 00:31


On Jan 23, 3:30 pm, Enrico C <use_replyto_addr...(a)devils.com> wrote:
> Do sat fat elevate cholesterol and CHD risk, regardless of total calories?
>
> What do you make of this "Saturated fat debate"?http://www.proteinpower.com/drmike/?p=345
> (it's a pro protein site, but protein is not the issue here)

Dr. Eades, who determines content of the website, has a low carb
cooking show on public TV where he advocates increased intake of omega
3 and foods high in omega 6. He does advocate the use of organic
butter.

> There you can read this letter published on the December issue of th
> American Journal of Clinical Nutrition (AJCN) ?

> LETTER TO THE EDITOR

> Saturated fat does not affect blood cholesterol
> Uffe Ravnskov
> Magle Stora Kyrkogata 9
> S-22350 Lund
> Sweden

> Dear Sir:

> The most striking observation from the study by Krauss et al (1) is the
> finding that a diet rich in saturated fatty acids (SFAs) results in a lower
> or a steady state concentration of total and LDL cholesterol and an
> increase in the concentration of HDL cholesterol, regardless of whether the
> diet has a reduced energy content. Similar effects on blood lipids have
> been observed in 4 weight-reducing trials with high intakes of SFAs
> (2-5)(Table 1) and in many similar trials with unrestricted intakes of
> SFAs.

Other papers show that it is the ratio of saturated fats that is
important, not the actual consumption, for determining cholesterol
levels. But cholesterol levels alone don't determine cardiovascular
risk.

--
Ron

From: Enrico C on 24 Jan 2007 12:35
On Wed, 24 Jan 2007 02:34:17 GMT, Jim Chinnis wrote:

> I have searched for evidence that saturated fat increases CHD risk without
> finding good evidence. I have gotten copies of most of the cited (old)
> studies.


According to this review article (2004), the association between sat fats
and CHD or stroke is "elusive" from an epidemiological point of view.


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=15294485&query_hl=1&itool=pubmed_docsum
Asia Pac J Clin Nutr. 2004 Aug;13(Suppl):S22.
Dietary fat quality: a nutritional epidemiologist's view.
[...]
| Between-population ecologic studies have demonstrated an association
| between intake of fat, specifically saturated fat and total cholesterol
| and coronary heart disease (CHD) mortality. However, results are
| inconsistent from within-population cohort studies. Likewise, the
| association between intake of total fat and saturated fat and with risk
| for stroke remains elusive.
[...]


Metabolic studies -they also say- showed a link between sat fats and
cholesterol levels but different SFAs have different effects.

| In metabolic studies different classes of saturated fatty acids (SFA)
| have different effects on plasma lipid and lipoprotein levels.
| Specifically, SFA with 12-16 carbon atoms tend to increase plasma total
| and LDL-chol levels, whereas stearic acid does not have a
| cholesterol-raising effect, but may lower HDL-chol especially in women,
| and increase Lp(a) concentration. Among the cholesterol-raising SFA,
| myristic acid appears to be more potent than lauric acid or palmitic
| acid, but the data are not entirely consistent.
[...]
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