HOMOCYSTEINE AND FOLIC ACID SUPPLEMENTATION
On March 15, 2015 JAMA published on line the results of a superbly designed and potentially practice changing trial. The China Stroke Primary Prevention Trial (CSPPT), tested whether or not the addition of folic acid to anti-hypertension medication could reduce the occurrence of a first stroke. As three quarters of all strokes are “first strokes” and as strokes are a leading cause of death and disability worldwide, the question posed by this trial had far reaching implications. The trial met its endpoint so quickly and incontrovertibly that for ethical reasons it was prematurely terminated. Folic acid can reduce the risk of stroke. Those of us who have open-mindedly interpreted prior studies expected this finding; many others found the results to be shocking.
Important homocysteine related trials like HOPE 2 and others had already demonstrated either statistically significant reductions in stroke with folic acid supplementation or at least signals toward such an outcome. Yet many of the most “vocal” researchers, physicians, and reporters proclaimed that since heart attacks were not reduced with folic acid, “the homocysteine hypothesis was dead.” This perspective always bothered me. We had observational and even interventional trial data supporting the use of folic acid in certain settings. And stroke, the disorder we could impact with a simple vitamin, is horrific. Strokes are terrifying, disabling, and deadly. They are also extraordinarily common. So why would these doctors, scientists, and media members snub data supporting a simple and safe vitamin treatment to potentially reduce such events? It would be helpful to know the reason, as the same phenomenon is currently occurring in relation to omega-3 fish oils.
Plenty of data support fish oil supplementation yet a few trials do not. And as with homocysteine, it seems that the media and many scientists/doctors have chosen to focus their attention on the limited neutral - and oftentimes overtly flawed - data rather than supportive experimental, biologic, physiologic, clinical trial, and common sense evidence. Interestingly, one of the vital lessons gleaned from CSPPT is that those individuals with either specific genetic mutations or very low levels of folic acid received the greatest benefit (reduction of stroke) from taking folic acid. In parallel fashion, one of the key trial limitations of fish oil studies has been the persistent failure to measure blood levels of the omega-3 fatty acids DHA and EPA. It certainly stands to reason that those with lower levels of these critical fats will also gain the greatest advantage from their supplementation. So why not simply measure them? Well, in clinical practice, some of us do. And some of us even advise correcting abnormally low levels with simple and safe fish and fish oil pill consumption.
I am at once elated and disturbed by the CSPPT findings. They prove the efficacy of a simple therapy; yet, they broadcast the hubris of many in my field. Time and again we have had to make an about face in our opinions and recommendations. I see nothing inherently wrong in changing our position as more data emerge. What I struggle with is the egg on our face, the about face that occurs far too late, long after adequate data have told us what to do. Perhaps we will learn though. Maybe as more trials like CSPPT emerge, as more scientists and doctors with the conviction and devotion to finding a greater truth push tirelessly along their paths we will finally learn to be more open minded and accepting of ideas and findings even when they go against our grain.
Laura Denson Baum, MD