Nice. Also to note: is this surprising? Don't we know that Korsakoff's causes brain atrophy because of a lack of B1?
At least, that's what I learned back in the old days... m -- Marc Carter, PhD Associate Professor and Chair Department of Psychology College of Arts & Sciences Baker University -- > -----Original Message----- > From: [email protected] [mailto:[email protected]] > Sent: Friday, September 10, 2010 12:46 AM > To: Teaching in the Psychological Sciences (TIPS) > Subject: [tips] B vitamins, Alzheimer's, and telling the whole story > > Our CTV television network, which prides itself in presenting > the very latest in medical advances, adequate evidence or > not, had another one tonight. A randomized controlled study > which showed that a 2-year regimen of B vitamins in the > elderly with mild cognitive impairment slows the rate of > MRI-assessed brain atrophy. > > But funny, I said to my wife, there's no mention of cognitive > improvement. Surely in a clinical study of this size and > sophistication, not to mention expense, they would measure > cognition before and after treatment. And if they did, > wouldn't they be bound to mention the outcome? Think again. > > The study turns out to be Smith et al (2010). They took a > battery of cognitive measures, all right, but there was > nothing in the methods I could see noting that they took > these measures after treatment as well as before. But > apparently they did. > > Buried in a section labeled "secondary outcomes" was this > statement "Although the study was not powered to detect an > effect of treatment on cognition (findings to be reported > separately), in a post hoc analysis we noted that final > cognitive test scores were correlated to rate of atrophy". > > My translation: We didn't find any difference between placebo > and vitamin treatments in cognition, so we did what we could > to put a positive spin on this, and also to forget about it. > Anyway, if we had more subjects, we might have seen something > (the "not powered" excuse). > > They provide a brief similar excuse ("not powered to detect > effects of treatment on cognitive test scores") in a later > section titled "Possible therapeutic implications". No data, > of course. > > But curiously, if one goes to where they registered their > trial before it began, they specified that in their study a > "primary outcome measure" was "Changes in performance on a > variety of cognitive tests". Nothing there about "not powered". > > See: > http://www.controlled-trials.com/ISRCTN94410159/94410159 > > So it seems that in their haste to get out the good news > (vitamins slow brain atrophy, which is indeed impressive), > they somehow avoided providing the bad news (no detectable > effect on cognition). Perhaps providing it would tend to > dampen sales for the products for which Dr. Smith is listed > as inventor with patents held by the University of Oxford and > on which he "could benefit financially" (see "competing interests"). > > > Stephen > > > Smith, A. et al (2010). Homocysteine-lowering by B vitamins > slows the rate of accelerated brain atrophy in mild cognitive > impairment: a randomized controlled tria. PLoS ONE, September > 2010, v. 5, issue 9, e1244 > > Available here: > http://tinyurl.com/Bvitamins-for-the-brain > > -------------------------------------------- > Stephen L. Black, Ph.D. > Professor of Psychology, Emeritus > Bishop's University > e-mail: sblack at ubishops.ca > 2600 College St. > Sherbrooke QC J1M 1Z7 > Canada > -------------------------------------------------------------- > --------- > > --- > You are currently subscribed to tips as: [email protected]. > To unsubscribe click here: > http://fsulist.frostburg.edu/u?id=13029.76c7c563b32ad9d8d09c72 a2d17c90e1&n=T&l=tips&o=4700 > or send a blank email to > [email protected] tburg.edu > The information contained in this e-mail and any attachments thereto ("e-mail") is sent by Baker University ("BU") and is intended to be confidential and for the use of only the individual or entity named above. The information may be protected by federal and state privacy and disclosures acts or other legal rules. If the reader of this message is not the intended recipient, you are notified that retention, dissemination, distribution or copying of this e-mail is strictly prohibited. If you have received this e-mail in error please immediately notify Baker University by email reply and immediately and permanently delete this e-mail message and any attachments thereto. Thank you. --- You are currently subscribed to tips as: [email protected]. To unsubscribe click here: http://fsulist.frostburg.edu/u?id=13090.68da6e6e5325aa33287ff385b70df5d5&n=T&l=tips&o=4708 or send a blank email to leave-4708-13090.68da6e6e5325aa33287ff385b70df...@fsulist.frostburg.edu
