I just saw this infographic on if particular substances are worth it for particular effects. Very interesting and useful illustration http://www.informationisbeautiful.net/visualizations/snake-oil-supplements/
OK so I think this is poor science & I spend a lot of time doing data analytics. Stuff like this irks me. My comments are not directed at you Nightingale, just at this kind of statistical analysis which I put firmly in the category of "marketing". This doesn't mean it's poor statistics but I worked with a brilliant statistician for many years and he would be deeply unimpressed with conclusions so whimsical.
1) The title of the graph is unscientific and is deliberately provocative.
It makes about as much sense as asking whether eating a balanced diet is "snake oil"?
2) I've read studies on some of the substances they've decided are snake oil myself that show chemical markers of their action BUT
3) When something is hyped then it leads to lots of additional research to determine if all kinds of efficacy claims are true
which actually leads to more negative results. The reason being that efficacy claims are subject to
a) placebo effects where people claim they've been cured of something they may not even have had and
b) determining dosages and quality of supplements is quite difficult. By the time a drug has gone to market there has been huge research into the effective dosage and treatment duration AND
c) tests of pharmaceutical drugs are done with knowledge of interactions whereas the same is rarely the case with supplements.
This is why something like vitamin C gets a bad rap. So many non-specific claims at indeterminate dosages that it's more likely a study will fail than succeed. Despite decades of pharmaceutical research failing to produce a cancer cure, Vitamin C fails on the wrong side of the tracks because it doesn't cure cancer. Same with ginkgo and alzheimers.
One reason why is that if you do a test of a Drug X from Y Corp
which is purported to alleviate some aspect of dementia, there is no way the researchers would use anything less than the stated clinical dosage of the drug. If they did and found less efficacy then Y Corp would immediately come out and rubbish the results. Your professor and dean would get a letter from Y Corp and you'd know not to be such a dumb ass in the future
In reality, your Uni department needs Y Corp's endowment and it's astonishing you were even taken on as a student when you're so
"unwise". Cynical perhaps!
This is by no means a bashing of big pharma. They do an important job and do it well. But they really really do not like the idea that ingesting large amounts of a cheap supplement would do away with billions of dollars of blockbuster drug revenue. Anecdotally, if POIS sufferers were used to study the efficacy of anti-depressants and anti-anxiety medication to treat their anxiety disease (POIS) then we'd conclude that anti-depressants were pretty useless and were snake oil
If you take a capsule of spirulina every morning expecting it to cure cancer then prepare to be disappointed but if you take it to increase the levels of tyrosine in your system then that's reasonable.