A new study just published in BMC Medicine examined the putative health benefits of cereal fiber. The authors, from the Harvard School of Public Health and the NutraSource company, which markets a variety of nutritional supplements, followed over 367,000 participants between the ages of 50 and 71 years. The survey from which the data were obtained began in 1995 and ended in 2009. They examined possible associations between the participants reported intake of cereal fiber and their risk of mortality from any cause. In addition, they also determined the risk of death from cancer, cardiovascular disease (CVD), diabetes, respiratory disease, and infections.
Participants in the highest 20 percent of intake of whole grains had a 17 percent lower risk of death from any cause than those whose reported intake was lowest. In addition, the highest intake group of cereal fiber had a 19 percent lower risk of death from any cause, as well as a 15 to 34 percent lower risk of death from specific diseases, but other factors were also likely involved for example, those with the highest cereal fiber intake also were more physically active than those in the lowest intake group.
Although one might conclude from these results that fiber is protective, commented ACSH s Dr. Ruth Kava, in fact these data do not come close to even supporting such a conclusion. She continued An observational study like this can only supply a possible link between variables in this case between either whole grains or cereal fiber and risk of mortality. Further, the reductions in risk were much too small to amount to anything relevant to the real world in an observational study, although some were statistically significant. And such studies, relying on self-reported data are known to have a high probability of error.