By Andrew Stewart
The August 20, 2008 edition of the Journal of the American Medical Association (JAMA) reported that B Vitamins did not work effectively to prevent death or cardiovascular events in a population of patients with coronary arterydisease or aortic valve stenosis. In the wake of this report, we’ve seen a vocal response from industry, claiming that the study is not credible, as it failed to acknowledge elements that could have altered the conclusions presented.
The study, conducted from 1999 through 2006, on 3,096 patients in two Norwegian hospitals, was headed by Dr. Marta Ebbing, M.D. at HaukelandUniversityHospital. Patients’ concerns about taking B vitamins to ward off cardiovascular problems, but at the same time, increasing the chance of cancer, resulted in the study being stopped prematurely.
The study divided participants into one of four groups; daily oral treatment of folic acid plus vitamin B12 and vitamin B6; folic acid plus vitamin B12; vitamin B6 alone; or a placebo. The doses of vitamins used in the groups were 0.8 milligrams of folic acid, 0.4 milligrams of B12 and 40 milligrams of B6.
One of many questions that quickly arose in study feedback was whether beta blockers, statins and anti-platelets were used for the duration of the study. The participants started the study while in their mid-60’s, and more than 75 percent of them had already been using the above mentioned drugs for existing heart disease.
Another issue with the study was that Norway does not add folic acid to its wheat as is done in the US, ostensibly, because they do not believe that fortified foods are necessary. This, in turn, meant that any folic acid, B-6 or B-12 through supplementation or other food that participants may have been taking at home was not factored into the study, and could have affected the results. Analysts also believe that the study involved too narrow a section of the population, and could not provide a proper answer to what B vitamin does for healthy people, arguing that folic acid supplementation should be considered from a preventative standpoint only.
With so many variables unaccounted for in the study, one might wonder how it still went on for years without intellectual intervention. Hindsight though, is 20/20, and the missing factors are quite evident in retrospective analysis.
Dr. Andrew Shao, of the Council for Responsible Nutrition (CRN), in an interview with NPIcenter, explained that groups like the CRN “try to caution against over-interpretation of results and broad sweeping conclusions that you hear from some people.” Shao added “B vitamins may not work for people who already have heart disease, but these studies don’t answer the question of whether the healthy population, if they take B vitamins on a regular basis over the course of decades, may be at a lower risk for heart disease.”
Industry frequently complains, in cases like this, about study design.
Shao observed, “The study was actually pretty well designed. Every study has limitations. No matter what, you’re always going to have limitations to a study, and it’s important to identify those limitations; if you’re overly critical of them, that is a really difficult position to have because no one is ever going to conduct the absolute perfect study that answers every question that anyone would possibly want to ask in the world.”
Despite what seem like flaws in the study, it is important to remember that a be-all, end-all cure was not the final goal for Dr. Ebbing and colleagues. The study was to see if B vitamin use would lower homocystein levels and help those with existing heart disease, not simply if B vitamin use would prevent heart disease, and it seems to have done that.
“You have a tool box of prevention, and there are all kinds of tools in there that you can use to try and keep yourself healthy and avoid disease,” said Shao. “Using supplements is just one of these tools, among a whole bunch. It is not THE tool, it is A tool. You have other components such as diet, stress, exercise [and] genetics, which is a tool you can’t do anything with but you’ve still got it. Supplements are just one of those tools. If that’s your outlook and you understand it… that’s where the benefit will be seen.”