Re: Coffee is number one source of antioxidants

In article <3nj0soF1oobmU1@xxxxxxxxxxxxxx>,
"Juhana Harju" <shantigiri@xxxxxxxxxxxxx> wrote:

> William Wagner wrote:
> : In article <3nic28F1jkanU1@xxxxxxxxxxxxxx>,
> : "Juhana Harju" <shantigiri@xxxxxxxxxxxxx> wrote:
> :: William Wagner wrote:
>
> ::: I just don't know!
> :::
> :: Coffee consumption is one of those J-shape things. Coffee has
> :: antioxidants, which is the reason 1-2 cups a day might be
> :: beneficial, but high consumption of coffee also raises homocysteine
> :: and the risk of acute cardiac events. Limiting coffee consumption to
> :: 1-2 cups a day is probably the best thing to do.
> ::
> : Thanks Juhana !
> :
> : The about url has a bar graph that compares the antioxidant levels.
>
> There are many analysis methods and the analysis method used in that site is
> likely to dismiss some important phytochemicals, which act as antioxidants,
> like anthocyanins.
>
> : Coffee is a mild diuretic useful for BP lowering which is of interest
> : to folks like me who take avalide.
>
> On the other hand caffeine might raise blood pressure - it is not that
> simple.
>
> J Hypertens. 2005 May;23(5):921-8. Related Articles, Links
>
> Blood pressure response to chronic intake of coffee and caffeine: a
> meta-analysis of randomized controlled trials.
>
> Noordzij M, Uiterwaal CS, Arends LR, Kok FJ, Grobbee DE, Geleijnse JM.
>
> Division of Human Nutrition, Wageningen University, Wageningen bJulius
> Center for Health Sciences and Primary Care, Utrecht University, Utrecht,
> The Netherlands.
>
> PURPOSE: Coffee is a widely consumed beverage and small health effects of
> substances in coffee may have large public health consequences. It has been
> suggested that caffeine in coffee increases the risk of hypertension. We
> performed a meta-analysis of randomized controlled trials of coffee or
> caffeine and blood pressure (BP). DATA IDENTIFICATION: BP trials of coffee
> or caffeine published between January 1966 and January 2003 were identified
> through literature databases and manual search. STUDY SELECTION: A total of
> 16 studies with a randomized, controlled design and at least 7 days of
> intervention was selected, comprising 25 strata and 1010 subjects. DATA
> EXTRACTION: Two persons independently obtained data on sample size, type and
> duration of intervention, changes in BP and heart rate (HR), and subjects'
> characteristics for each trial. Meta-analysis was performed using a
> random-effects model. RESULTS: A significant rise of 2.04 mmHg [95%
> confidence interval (CI), 1.10-2.99] in systolic BP and 0.73 mmHg (95% CI,
> 0.14-1.31) in diastolic BP was found after pooling of coffee and caffeine
> trials. When coffee trials (n = 18, median intake: 725 ml/day) and caffeine
> trials (n = 7, median dose: 410 mg/day) were analysed separately, BP
> elevations appeared to be larger for caffeine [systolic: 4.16 mmHg
> (2.13-6.20); diastolic: 2.41 mmHg (0.98-3.84)] than for coffee [systolic:
> 1.22 mmHg (0.52-1.92) and diastolic: 0.49 mmHg (-0.06-1.04)]. Effects on HR
> were negligible. CONCLUSIONS: Regular caffeine intake increases BP. When
> ingested through coffee, however, the blood pressure effect of caffeine is
> small. PMID: 15834273
>
> --
> Juhana
......................................................

Dam Statistics. ;))) Last quote in below post is interesting.

Bill

http://www.newscientist.com/article.ns?id=dn7915&feedId=online-news_rss20


 
Most scientific papers are probably wrong
? 02:00 30 August 2005
? NewScientist.com news service
? Kurt Kleiner

Most published scientific research papers are wrong, according to a new
analysis. Assuming that the new paper is itself correct, problems with
experimental and statistical methods mean that there is less than a 50%
chance that the results of any randomly chosen scientific paper are true.
John Ioannidis, an epidemiologist at the University of Ioannina School
of Medicine in Greece, says that small sample sizes, poor study design,
researcher bias, and selective reporting and other problems combine to
make most research findings false. But even large, well-designed studies
are not always right, meaning that scientists and the public have to be
wary of reported findings.
"We should accept that most research findings will be refuted. Some will
be replicated and validated. The replication process is more important
than the first discovery," Ioannidis says.
In the paper, Ioannidis does not show that any particular findings are
false. Instead, he shows statistically how the many obstacles to getting
research findings right combine to make most published research wrong.
Massaged conclusions
Traditionally a study is said to be "statistically significant" if the
odds are only 1 in 20 that the result could be pure chance. But in a
complicated field where there are many potential hypotheses to sift
through - such as whether a particular gene influences a particular
disease - it is easy to reach false conclusions using this standard. If
you test 20 false hypotheses, one of them is likely to show up as true,
on average.
Odds get even worse for studies that are too small, studies that find
small effects (for example, a drug that works for only 10% of patients),
or studies where the protocol and endpoints are poorly defined, allowing
researchers to massage their conclusions after the fact.
Surprisingly, Ioannidis says another predictor of false findings is if a
field is "hot", with many teams feeling pressure to beat the others to
statistically significant findings.
But Solomon Snyder, senior editor at the Proceedings of the National
Academy of Sciences, and a neuroscientist at Johns Hopkins Medical
School in Baltimore, US, says most working scientists understand the
limitations of published research.
"When I read the literature, I'm not reading it to find proof like a
textbook. I'm reading to get ideas. So even if something is wrong with
the paper, if they have the kernel of a novel idea, that's something to
think about," he says.
Journal reference: Public Library of Science Medicine (DOI:
10.1371/journal.pmed.0020124)

--
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This article is posted under fair use rules in accordance with
Title 17 U.S.C. Section 107, and is strictly for the educational
and informative purposes. This material is distributed without profit.
.

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