Non-sequitur

This post has nothing to do with the blog's purpose.

There've been a lot of studies published lately about Alzheimer's; that's to be expected, as it's a common disease and thus readily funded. There's still few enough of them that I can read them and gripe about bad research.

Post Traumatic Stress Disorder

It's been found that soldiers diagnosed with PTSD are much more likely to have Alzheimer's. Though it's known that high levels of stress can exacerbate many problems, what this really comes down to is that those whose mental function is regularly checked are more likely to get diagnosed with Alzheimer's. No surprise there!

Curcumin

It's been noticed that Alzheimer's is less common in some cultures than others. This led to a study of diets and it was found that those who consumed the most curcumin (found in cumin and especially in turmeric) had the lowest rates of Alzheimer's. Curcumin is an antioxidant, but there's no explanation why this one should be different from others - this is a classic case of "correlation is not causality." Those who have diets high in curcumin have a cluster of other factors in common, such as diets low in saturated fat and high in vegetables.

Caffeine

Studies in mice have shown that high doses of caffeine (equivalent to 500 mg. for humans, about a pot of coffee) help with memory in those with dementia. Mice are not exactly a good model for these studies. It's been known for a long time that caffeine aids in basic rote memorization, but has no effect on higher reasoning. This study says nothing useful.

Alcohol

Those who drink one alcoholic beverage per day have lowered incidence of Alzheimer's, though those who consume more have increased incidence, compared to those who do not drink. High amounts of alcohol are poisonous, so half of this study is obvious. Small amounts of alcohol have been known to have some protective effect on vascular disease and thus on some causes of dementia, but this would not affect Alzheimer's. It's currently impossible to diagnose Alzheimer's with certainty in a live person.

There is a possibility that alcohol may act as a solvent which increases the absorption of some other protective factor. For example, when it was seen that tomato paste was linked to lower prostate cancer risk, lycopene (essentially, the red pigment of tomatoes) was tested and found to have no effect. Lycopene is not water soluble. Tomato paste is usually cooked with oil, in which it is soluble. People don't take their pills with oil.

Caloric Restriction

Anecdotal evidence and studies in other animals have suggested that a nutrient-dense but near-starvation diet is protective against many diseases. A recent study had women in their 60's cut their calorie intake by 30% for weeks and then take a test of verbal memory. Those who adhered best to the diet performed best on the tests. This just means that those who were motivated to do one thing were motivated to do another.

So many studies, so much bad science...

Note added: There was actually a fairly good study recently, showing that the omega-3 fatty acid DHA has no effect on Alzheimer's symptom severity.