HOPE not Lost in New Vitamin B Findings

HOPE not Lost in New Vitamin B Findings

WASHINGTONTheNew England Journal of Medicine (NEJM) published results of two vitamin B-cardiovascular health trials online March 12, in conjunction with the American College of Cardiology (ACC) Annual Scientific Session held in Atlanta. Also presented at the ACC meeting, the results from both the HOPE-2 and NORVIT trials showed vitamins B6, B12 and folate lowered homocysteine levels in cardiovascular disease (CVD) patients, but this failed to translate into protection from future CVD events. However, nutritional products advocates countered these two studies, while important for the greater body of research, offer limited useful data for the general public, as they fail to address the appropriate CVD population and endpoint.

In the HOPE-2 (Heart Outcomes Prevention Evaluation) trial, 5,522 patient 55 years or older and with vascular disease or diabetes were given either a placebo or a combination of B6, B12 and folic acid daily for five years. Researchers looked for death from CVD, myocardial infarction (heart attack) and stroke. Homocysteine decreased significantly in the supplement group and increased slightly in the placebo group, but deaths from CVD or myocardial infarction; however incidence of stroke was lower in the vitamin group. Nonetheless, the researchers concluded the vitamin B combination did not reduce the risk of major CVD in patients with vascular disease.

Similarly, the NORVIT (Norwegian Vitamin Trial) involved 3,749 men and women who had suffered myocardial infarction within seven days before the trial start. These patients were randomized to receive daily either a placebo or one of three different vitamin B combination treatments; for four months, they were monitored for recurrent myocardial infarction, stroke and sudden death attributable to coronary artery disease. The combination of B12 and folic acid lowered homocysteine levels by as much as 27 percent, but did not impact the primary endpoints compared to placebonor did any of the supplement treatments. The researchers concluded B vitamins did not lower the risk of recurrent CVD following acute myocardial infarction and indicated the vitamin B treatment actually showed a trend toward increased risk of CVD.

Annette Dickinson, Ph.D., consultant and past president of the Council for Responsible Nutrition (CRN), cautioned while these studies contribute importantly to the research base, they have limited application for the general population, as these studies did not test whether B vitamins can help keep healthy people from developing CVD. Instead, the studies looked at whether B vitamins can treat or reverse heart disease in people who already have it, a benefit more appropriate for drug research than for vitamins, which are best used in prevention and should not be expected to perform like drugs. CRN further noted it is unrealistic to expect a vitamin to undo damage caused by heart disease, and consumers should not be looking for B vitamins to treat disease. Considering the patients studied in these trials were already seriously ill, Dickinson questioned whether these subjects would have been healthier to begin with if they had been taking B vitamins and other supplements consistently over time.

Agreeing the studies were well-designed and executed for the purposes for which they were created, Dickinson explained the major flaw of these trials is in the reasoning currently underpinning many clinical trials on nutrient intervention. There are practical reasons related to cost, duration and the size of the study group why these trials are conducted in high risk or diseased populations, she said. Our best advice to healthy consumers is not to throw away your vitamins based on the study du jour.

CRN pointed to the positive result in the HOPE-2 study showing a statistically significant 25-percent reduction in nonfatal strokes. However, the study authors suggested this benefit this may be due to chance. To this, CRN reiterated similar results on strokes have been found in previous vitamin B trials.

CRN reported at least 10 clinical trials are now on-going or have been recently completed looking at whether B vitamins can reduce the risk of CVDmostly in high risk or already diseased populations. The group emphasized consumers and professionals need to view every new study in context, cautioning against the tendency to look at every trial as conclusive advice for the general population.

Both studies are slated for print publication in the April 13 issue of NEJM (http://content.nejm.org).