Adding highly refined fiber to processed foods could have negative effects on human health, such as promoting liver cancer, according to a new study by researchers at Georgia State University and the University of Toledo.
Accumulating evidence demonstrates consumption of whole foods naturally rich in fiber confers an array of health benefits. This, combined with an appreciation by many health-conscious consumers that their diets are lacking in such fibers, has led to the food industry enriching foods with highly refined soluble fibers, such as inulin. Recently, changes in U.S. Food and Drug Administration rules allow foods containing supplemented fibers to be marketed as health-promoting. This study raises serious concerns about the safety of adding refined fiber to processed foods.
The researchers set out to test the idea that a diet enriched with refined inulin might help combat obesity-associated complications in mice. While such an inulin-containing diet did stave off obesity, some of the mice started to develop liver cancer.
“These findings indicate that enriching foods with purified fibers may not recapitulate the benefits of eating fruits and vegetables naturally rich in soluble fiber,” said Dr. Andrew Gewirtz, professor in the Institute for Biomedical Sciences at Georgia State and one of the study’s authors. “Moreover, it may result in serious, life-threatening liver cancer in some individuals. Hence, we think the recent FDA rule change that has effectively encouraged marketing of fiber-fortified food as health-promoting is ill-conceived and should be reconsidered.”
Earlier this year, the FDA issued guidance which identifies eight specific fibers that can be classified as “dietary fibers” on the upcoming Nutrition Facts Label, marking the end of two years of uncertainty for manufacturers. Among these was also the inulin fiber used in the study.
The study was funded by grants from the National Institutes of Health, a Research Fellowship and Career Development Award from the Crohn’s and Colitis Foundation, Belgium Fonds de la Recherche Scientifique FRS-FNRS and the European Research Council.