Dangers with Self-diagnosis and Prescription

Almost every day a study or two comes out in the news telling what substance(s) may improve health or reduce the chances of catching some disease.  Notice that they invariably use the word may.  Often these are preliminary studies that require confirmation by duplication, application to a larger sample size or experimental rather than observational design.  The news may be in response to a press release from the researchers themselves or a standard report on a journal article.

Two came my way a couple of days ago.  One said that Vitamin C may prove effective in preventing leukemia, a blood cancer.  The second reported that lithium may lower the incidence of dementia.

I looked up the Vitamin C news on msn.com and was immediately suspicious based on the first sentence that began, “Vitamin C has long been associated with maintaining a healthy immune system and warding off the common cold.” 

Hold on a minute!  NPR ran a program back in 2006 called The Vitamin C Myth in which their expert stated, “There's very little evidence available that shows that vitamin C in mega doses is good for anything.”  This is supported by other reviews of studies discussed here and here.  There is some evidence that it may slightly reduce the duration and intensity of a cold, but that doesn’t mean taking extra Vitamin C does any good.

The Mayo Clinic reminds us that a healthy diet ordinarily provides enough Vitamin C for most Americans.  “A large orange or a cup of strawberries, chopped red pepper or broccoli provide enough vitamin C for the day. Any extra vitamin C will simply be flushed out of your body in your urine.”  Those mega-doses are usually harmless, but they don’t do any good, are flushed down the toilet and can cause some people to experience unwelcome side effects including: diarrhea, nausea, vomiting, heartburn, abdominal discomfort, headaches, insomnia or kidney stones.

That first sentence shows the writer being sloppy or careless or misinformed.  But setting aside that issue, the conclusion of the article was, “Vitamin C deficits in the body may help contribute to leukemia,” so it may play a role in leukemia prevention.”  Since the already popular advice of eating a healthy diet precludes deficits, there’s no news here.

I moved on to do some research on lithium for dementia.  This was based on an observational study from Denmark where the researchers identified the amount of lithium naturally found in the drinking water in various parts of the country and looked for the relative incidence of dementia in the different populations over a long period. Results were published last month in JAMA Psychiatry.  “Higher long-term lithium exposure from drinking water may be associated with a lower incidence of dementia.”  The watch-out was that the association was nonlinear, that is, certain levels seemed to be effective and others did not – larger or smaller doses did not produce proportionate results.  So getting the proper dose was fairly critical.

The positive effects of lithium have been studied for a long time as shown by this 2003 headline: “Bipolar Drug Keeps Mouse Brains Free of Damaging Plaque.”  Again this is just a further investigation of the hypothesis that lithium may have some effect on dementia – advancement in understanding, but nothing earth shattering.

The concern is that news of this nature that highlights possible relationships comes at us constantly.  Because dementia, which most people think of as Alzheimer’s, a well-publicized subset of broader memory problems, is scary, as is leukemia or any kind of cancer; it is likely that some people hearing news like this will dash out to the health food store and stock up on whatever may prevent one disease or reduce the effects of another.  The next thing you know, the kitchen table is littered with supplements.  The problems are, as these two examples clearly show, doses are not definite, effects are not proven and dangers lurk in the details.