ASN: Whole grain and bran ‘modestly’ associated with chronic disease risk reduction
Supporting the potential health benefits of whole grains and cereal fiber, the new ASN position paper published in the American Journal of Clinical Nutrition states that: “There is reasonable evidence for an inverse association of intake of cereal fiber or mixtures of whole grains and bran and risk reductions for type-2 diabetes and cardiovascular disease.
“However, the relation is less convincing for whole grains by themselves when using the currently accepted definition,” wrote the researchers, led by David Klurfeld from the USDA/Agricultural Research Service.
The project was funded by CJ CheilJedang, Garuda International, and the Kellogg Company.
Whole Grains Council
Cynthia Harriman, director of food and nutrition strategies for Oldways / The Whole Grains Council, told FoodNavigator that the ASN paper points out the importance of both whole grains and cereal fiber for health.
“Oldways and the Whole Grains Council agree that, going forward, it's important that research should more clearly define the variety and quantity of whole grain foods used in studies, so that stronger conclusions can be reached about whole grains and health. Since the cutoff date in the study (December 2010), better research is already being done which could potentially change the conclusions of this paper.
“Studies like these, which surface periodically, can also be interpreted as reminding us that no matter how whole grain is defined, it's linked with health -- so the lack of studies using one particular definition (that of the FDA health claim) does not necessary mean much. Common sense still tells us that foods with all their original nutrients intact will be healthier than foods with a large proportion of nutrients removed.
“We think that bran and whole grains are both good choices. There shouldn't be a competition between the two. Let's concentrate instead on switching away from refined grains.”
Guidelines
The 2005 and 2010 Dietary Guidelines for Americans (DGA) recommend that whole grains should account for at least half of the recommended 6 to 11 daily grain servings to reduce the risk of chronic diseases.
However, recent data published in the American Journal of Lifestyle Medicine found that only one in ten US consumers gets the recommended amount of fiber, and that the average US consumer needs to double daily fiber intake said the “chronic shortfall” in fiber intake levels has long-term implications for public health and must be changed.
Data from the NPD Group indicated that consumption of whole grain products increased by over 20% between 1998 and 2008. The Whole Grain stamp has gone from strength to strength, and now features on more than 8,600 products in 41 countries.
While eligibility for the stamp starts at 8g whole grains per serving, most products featuring it are said to contain significantly more, with almost two-thirds now containing at least twice this amount.
ASN position
Dr Klurfield and his co-workers performed a comprehensive literature search of human studies investigating the contribution of bran or cereal fiber on the impact of whole grains for chronic disease risk reduction.
The Society paper states that, based on the current science, the risk of obesity, type-2 diabetes, and heart disease are ‘modestly’ reduced by consuming foods rich in cereal fiber or mixtures of whole grains and bran.
“Our review supports the summary from the Life Sciences Research Office, which stated that the associations between whole-grain intake and risk reduction for T2D and CVD are inconclusive when the definition of whole grain does not include added bran,” wrote Klurfeld and co-workers.
“Similar conclusions were reached by the European Food Safety Authority, which rejected health claims related to whole grains (blood cholesterol concentration, carbohydrate metabolism and insulin sensitivity, low glycemic index, weight control, and weight management, among others).
“These conclusions may be due, in part, to the following factors: 1) very few studies had a long follow-up period; 2) different types of whole grains may have different physiologic roles, thus it is difficult to reach a conclusion from studies investigating the effects of one type of whole grain; and 3) the limited number of studies investigated whole-grain effects alone (ie, most whole-grain studies are confounded by the inclusion of bran cereals).”
Source: American Journal of Clinical Nutrition
Published online ahead of print, doi: 10.3945/ajcn.113.067629
“Consumption of cereal fiber, mixtures of whole grains and bran, and whole grains and risk reduction in type 2 diabetes, obesity, and cardiovascular disease”
Authors: S.S. Cho, L. Qi, G.C. Fahey Jr, D.M. Klurfeld
