Why do they have studies like this one today about decaf coffee.
For $1-million they compare the HDL and LDL blood levels after either drinking decaf or regular for a week.
The result in general was known before they started: The levels will vary a little.
So, then they guess about the reason why.
Why wait to guess at the end of the study?
They knew either the numbers could only be identical or different.
Only two possible results.
Why not prepare for the obvious, do your guessing before the study, and test the guess during the study?
So anyway, their guess is “Fats give coffee flavor, and a more flavorful species of beans, robusta, is commonly used for decaf to make up for the flavonoids and other ingredients that are lost during the decaffeination process. Regular coffee uses a different bean, arabica.”
The obvious thing to do, had you made that statement up front, is to either test decaf robusta vs. regular robusta. Or, regular robusta vs. regular arabica. Or both of those tests, independently.
That’s called standard scientific procedure. Test only one variable at a time.
So the question is, why did someone give them $1-million and not anticipate one of only two possible results.
Science works by division of labor. One group does a statistical study and reports the result in an academic journal. They’d suggest possible reasons, but that’s just fluff - a “discussion”. Someone else would then look at the reported results, and performs experiments and studies to find the reason behind it.
It should also be noted that the test was using the typical product available to the public. ie decaf robusta vs normal arabica. Thus is more useful in answering the question should someone be recomended to have decaf or not.
When dealing with people it’s almost impossible to test one variable at a time. It’s almost impossible when dealing with any animals, but people make it harder again because we can’t readily cage them and force feed them.
You suggest testing decaf robusta vs. regular robusta or regular robusta vs. regular arabica. Unfortunately people are clever enough to know the difference. As the article you linked to points out decaf coffee has less flavour than regular coffee made with the same beans. So if you try to test regular vs. decaf you are going to be testing people’s flavour preference as well as the physiolgical effects. If people find the taste of decaf arabica bland, or the taste of regular robusta overpowering hey won’t drink as much, or they won’t drink as fast, either of which affects your study.
There’s no easy way to do a true double blind study on this subject. Coffee isn’t a tablet, people know what it tastes like and they drink it for the taste. For meainingful results the taste of decaf and regularhave to be comparable. If, as in this case, that introduces complictaing factors then you have to attempt an entirely different series of trials to account for that.
It’s also pretty much impossible to tell what a study was actually all about and what it found based on a short media blurb about it. Even if the reporter got the main conclusion right, they are often edited into nonsense by the time they reach the public.
I hate to point it out to you, but you completely missed what the study was about, and also my question.
The study was not a double-blind, or even a blind test. And preferece had absolutley nothing to do with it. They were told what to drink and what they were drinking.
And my question was why run the test when the only possible result will be that you are asked to state what the test means, and you have no clue but end up guessing. Why not just start off guessing and save the million for the real test.