Coffee Consumption Strongly Linked To Preventing Alzheimer's 205
An anonymous reader writes "Those cups of coffee that you drink every day to keep alert appear to have an extra perk — especially if you're an older adult. A recent study monitoring the memory and thinking processes of people older than 65 found that all those with higher blood caffeine levels avoided the onset of Alzheimer's disease in the two-to-four years of study follow-up. Moreover, coffee appeared to be the major or only source of caffeine for these individuals."
Small Sample? (Score:4, Insightful)
124 people in the study is pathetic. Why wouldn't they get a bigger sample size for a study like this? Not like it should be difficult. Apparently a study published in the New England Journal of Medicine included over 400,000 older adults in similar study.
Re:Anecdotal Evidence (Score:4, Insightful)
Or necessarily false either. Had she not been drinking coffee, the onset might have started a decade earlier.
Re:Small Sample? (Score:5, Insightful)
In all seriousness, huge sample sizes are only important if we are comparing several variables, where a large sample size can give us good estimates for rare combinations of events, and/or small effects, where a large sample size allows us to achieve small confidence intervals over the relevant comparisons. It's quite possible for a sample size of 124 to yield a significant difference for one effect if the effect is of at least moderate size.
Re:So, I suspect that a good strong cup of tea ... (Score:5, Insightful)
Honestly, as long as the point comes across you shouldn't really care.
But it didn't come across. I was about to google "florine" to find out what I had missed when I saw the GN's post. Because I'm not a phonetic reader, it never occurred to me that florine might be fluorine.
The devil is in the details. Being imprecise not only sends someone on a wild goose chase, but also means no distinction between fluorine, fluorene and fluoride, all of which are quite different things. And it's not fluorine that's thought to be a problem, but fluoride compounds, specifically hydrogen fluoride. It's as wrong as saying oxygen when you mean ozone.
Re:So, I suspect that a good strong cup of tea ... (Score:5, Insightful)
What's that whooshing sound?
(Ok, I'll explain it... drinking lots of Coke every day does increase cholesterol and lead to obesity and such... and increasing your chances of dying early before Alzheimer's kicks in. So yes, the odds of dying from Alzheimer's go down, because you're much more likely do die earlier from something else.)
Re:So, I suspect that a good strong cup of tea ... (Score:4, Insightful)
On the plus side, if the caffeine is the causative agent, supplementation would be pretty easy.
Possibly, but perhaps caffeine doesn't have anything to do with it. I think the phrase "correlation does not equal causation" is something of a cliche, but it's a cliche for a good reason. We know that there's an association, but because this isn't an experiment with a control and a treatment, we don't know why that association exists.
For an example of how this logic can break down, consider a recent study of coffee (again) that found that nurses drinking lots of coffee suffered lower rates of depression. So coffee has antidepressant effects, right? Well, that's one possible explanation. Here's another possible explanation: symptoms of depression include anxiety and trouble sleeping. So if you're anxious and can't sleep at night, the last thing on earth you want is 4-5 cups of coffee a day making you wired, twitchy, and wakeful. So yes, one reading is "coffee drinking reduces depression" but an equally plausible reading of the data is "depression reduces coffee drinking." The only way to tease it apart is with an experiment: take a population, give half of them coffee, give half of them decaf (to control for placebo effect), and see whether the incidence of depression varies between the two. So what's the answer? Nobody knows.
Likewise, we have to look at the possibility that decreased coffee consumption is caused by Alzheimer's. If coffee is part of your morning ritual and social functioning, then as you become less functional, you might forget to make that morning cup and have trouble interacting with people at the coffee shop. So perhaps Alzheimer's causes people to drink less coffee. The only way to figure it out is to take a population and give half of them coffee, and half of them decaf, and see how they do.