phoenix said:
Full study
http://archinte.ama-assn.org/cgi/conten ... 2011.2287v
Haven't read it yet. Do find it slightly ironic that it's lead author is Frank Hu. He also was the author of the meta-analysis on Sat fats last year,
http://www.ajcn.org/content/early/2010/ ... 5.abstract.
You know, the one that some people use to suggest eating sat fat is OK.... yet exactly the same sort of evidence.
The difference comes in that this recent study used data collected from four yearly food frequency questionnaires(FFQs)
* where the two studies included
were not designed to test the hypothesis "red meat increases health risks" -- in effect making this a
retrospective cohort study... on the other hand the Sat Fat meta-analysis selection criteria
** states...
Studies were eligible if 1) data related to dietary consumption of saturated fat were available; 2) the endpoints were nonfatal or fatal CVD events, but not CVD risk factors; 3) the association of saturated fat with CVD was specifically evaluated; 4) the study design was a prospective cohort study; and 5) study participants were generally healthy adults at study baseline.
...in other words: it
only included studies that were designed to test the hypothesis in question.
Neither method is good for much more than showing an association -- the lack of which is
all that they concluded in the Sat Fat analysis
*** -- and neither can be used to predict precise percentages of cause and effect as has been shouted by these headlines... that would require further testing of specific hypotheses (RCTs for example).
As the various reviewers have been quick to point out: this same Nurses Health Study was used to predict a significant percentage of protection for women taking Hormone Replacement Therapy (HRT) which later proved to be fatally wrong when tested in controlled trials -- IIRC the controlled trials turned an estimated 44% protection from CVD around to a 29%
increase in CVD for those on HRT... how many deaths later... how much "wronger" can you get?!?
Particularly questionable are the FFQs which have those in the group
self-reporting the least red met consumption, averaging just
1,200 calories per day -- bearing in mind that these are hard-working nurses, on their feet for 12 hour shifts.
On the plus side these same data can be used to show that those with the
highest [reported] red meat consumption had the
lowest cholesterol levels! :crazy:
Denise Minger (perhaps not as popular as GT
but definitely cuter) has done a bang-up job of reviewing this red meat study as guest poster at Mark's daily Apple...
http://www.marksdailyapple.com/will-eating-red-meat-kill-you/#axzz1pHG04hRv
*http://www.channing.harvard.edu/nhs/questionnaires/pdfs/NHSI/2002.PDF
**http://www.ajcn.org/content/early/2010/01/13/ajcn.2009.27725.full.pdf+html
***
A meta-analysis of prospective epidemiologic studies showed that there is no significant evidence for concluding that dietary saturated fat is associated with an increased risk of CHD or CVD.