does caffeine prevent Alzheimer's

taurusrc at pacbell.net taurusrc at pacbell.net
Tue Jul 16 13:54:42 EST 2002


There are too many variables involved to make an informed decision.  For
example:

The study was based on coffee intake.  Was that strong coffee or weak coffee.
Why wasn't the study done using caffeine.  

Many people lower their intake of coffee because it makes them nervous or gives
them insomnia.  Perhaps people who get that reaction from coffee are more prone
to AD.

It seems to me that some studies should not be published.   What is the point.


Ora


On Tue, 16 Jul 2002 04:33:55 GMT, in sci.med.nutrition you wrote:

>Eric S <erics_news_addyl at yahoo.dawt.cawm> wrote in news:3D338E55.4020007
>@yahoo.dawt.cawm:
>
>> Have you all seen this yet?
>
>> http://www.news.com.au/common/story_page/0,4057,4705704%5E2,00.html
>
>> Looks like my current caffeine quota might need raising. Oh darn. ;^)
>
>Here's the abstract of the actual study (you've got to pay for the full 
>text).  Of course, we coffee drinkers knew it all along, smart as we are.
>
>The study compared the caffein intake of 54 persons with AD to 54 without 
>AD.  This number seems pretty small to me.  Perhaps one of our astute 
>mathematicians/statisticians would like to comment.
>
>Like most other studies it will have to be confirmed/disconfirmed by future 
>work.
>
>I added sci.med, sci.med.nutrition, and bionet.neuroscience in the hopes of 
>generating additional informed discussion, since this is a serious issue.



On Tue, 16 Jul 2002 11:42:54 -0400, "Larry Hoover" <larryhoover at sympatico.ca>
wrote:


>First off, it isn't an "enormous range of error" being reported. It's the
>standard deviation. It does suggest that there is a large variability within
>the defined groups, but it is the between-groups measure that has a
>significance of  P < 0.001. That significance was found when a comparison of
>the mean values for the two groups, with full regard to the variability
>within the groups, was made.
>
>"Patients with AD
>had an average daily caffeine intake of 73.9 +/- 97.9 mg during the 20
>years that preceded diagnosis of AD, whereas the controls had an average
>daily caffeine intake of 198.7 +/- 135.7 mg during the corresponding 20
>years of their lifetimes (P < 0.001, Wilcoxon signed ranks test)."
>
>The sample groups were probably too small to break down each group into
>high-caffeine, mid-caffeine, and low-caffeine ranges, but I'd be interested
>in seeing something like that. I'm sure it's being looked at right now.
>
>If you look at this part of the findings:
>
>" Using a
>logistic regression model, caffeine exposure during this period was found
>to be significantly inversely associated with AD (odds ratio=0.40, 95%
>confidence interval=0.25-0.67), "
>
>...what you see is that even at the upper end of the confidence interval
>(i.e. the range of values for which P < .05), the value is less than unity.
>So, however you cut it, caffeine exposure seems to be strongly and inversely
>correlated with Alzheimer's. Why is still anybody's guess.
>
>> It somewhat bothers me that they have framed it in terms of caffeine
>> intake. I assume that they didn't actually have real measurements of
>> caffeine intake, but estimated these from the subjects' reported daily
>> intake of coffee, tea, etc (the reason why the margin of error is so
>> large?). To me that's putting an assumption on the data from the outset,
>> that caffeine is the (only) relevant component of what they are actually
>> measuring.
>
>Tea, coffee, and cola drinks are very different than each other. Teasing out
>which is better or worse has yet to be done. The variability in the caffeine
>consumption has nothing to do with the type of drink. It just happens to be
>the variable they measured. You can be sure people will want to know if
>there are other confounding variables being coincidentally measured in this
>study. Stay tuned.
>
>> For example, if coffee were the primary source of the caffeine intake
>> difference in the groups, might there not be another component of coffee
>> that could responsible for the protective benefit alone or in
>> combination with others (including caffeine)? In any case coffee, tea,
>> etc are the real ways most people ingest caffeine, so knowing the
>> statistical relationship between actual coffee consumption, tea
>> consumption, etc. is more valuable to most of us anyway, regardless of
>> the ability to determine what compounds are responsible.
>>
>> Eric
>
>A bigger, more comprehensive study, is sure to follow.
>
>Larry
>




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