Another study on whether coffee-drinking is good for you is making the rounds in the popular press, from Harvard, so it has some cred. Actually, it’s a meta-analysis and a new study that purports to include the biggest data set to date. (All the research geeks are excited now.) If you want to read it, it’s linked here: https://www.ahajournals.org/doi/full/10.1161/CIRCULATIONAHA.115.017341
I guarantee that no matter how many cups of coffee you have had, it will put you to sleep, but that’s not my observation today. I’m pointing out that this highly-touted study in a reputable research journal is practically useless for telling us if drinking coffee, specifically “3 cups a day”, is good at keeping death away. Those who aren’t medical researchers can perhaps already tell that avoiding death is probably a complex process that even complex statistics cannot fully explain, but I want to point out the most basic failures of research design here:
1) They never specify how much coffee is in a “cup.” The SCAA says it’s 5oz, most coffee chains use 8oz as the measure, and who knows how much your travel mug holds. And how much of your coffee is coffee and not milk, sugar, foam and of course, water?
2) While they apparently kept track of whether the coffee was decaf or full-caf, no measure of brew strength was specified. I can tell you my daily brew is way stronger than “church coffee.” Does that make a difference? I’ll bet it does.
3) There was no teasing out statistics on those whose coffee-drinking also included ingesting cigarette smoke. I’d think that would muddy the statistical waters enough as to render the whole effort null.
Harvard, say it ain’t so. You can do better than this! I’m going to have my “2nd” cup….