South Korean Research: Coffee may ward off heart problems.
Coffee may ward off heart problems but more studies are needed, say South Korean researchers - ABC News (Australian Broadcasting Corporation)
From the article:
People who drink three to five cups of coffee a day may have a lower risk of developing clogged arteries that can cause serious heart problems, a study reports.
The study follows research which has claimed the popular brew leads to a reduced risk of developing multiple sclerosis, Parkinson's and Alzheimer's disease.
For the latest study, researchers analysed data from 25,100 South Korean men and women with an average age of 41 who had undergone regular health screening.
Every coin has two sides. Depends on what you want to achieve, simply manipulate it...
Originally Posted by ibiza888
I doubt any Korean researchers will be blatantly manipulating data after their human cell cloning scandle 10 years ago. Mind you... it does seem a bit odd to exclude any participants with cardiovascular problems from the study, and then proceed to draw conclusions regarding the cardiovascular heatlh of the remaining participants.
I always suspect that these coffee studies are affecting by 'confounding factors', i.e. people that drink over 3 cups of coffee a day are probably more physically and mentally active than those who don't.
Based only on the linked media article, I'm not sure that it suggests that the researchers systematically excluded participants with cardio problems. It just says that of the sample of people regularly screened for health problems, none of them had cardio problems. i.e.
Originally Posted by burr
"None of the study group had any cardiovascular problems, but one in seven had detectable levels of coronary artery calcium (CAC), an early sign of coronary heart disease or atherosclerosis."
Hehehe I actually skimmed through the article before :
"We excluded 437 participants with a history of CVD, 474 participants who had implausible estimated energy consumption levels (beyond 3 SDs from the loge-transformed mean energy consumption), 1824 participants with missing information on coffee consumption, and 3371 participants with missing information on smoking status. The final sample size for the analysis was 25 138 participants (figure 1)."
however I would value the opinion of an epidemiologist over my own regarding the study design
I guess that could suggest though that they excluded people who had CVD at the beginning of (or throughout) the study period? Depends what exactly 'with a history of' means in relation to the study period (i.e. could it mean that they had a pre-existing condition at the time they entered the sample). Would induce an obvious selection bias if they excluded subjects who were clean at the start of the study period and subsequently developed CVD.
I'll have a proper read later, but I assume that anyone with CVD before or during the checkup period was excluded. They didn't do these health checkups for the purpose of investigating the effects of coffee, they just got access to the results of people's health checkups. I.e. they could look at the effect kimchi consumption on the same factors.