Carbohydrate staple foods - facing the challenge to improve their quality for a better metabolic health
Carbohydrates are the main energy source in most European diets. Their metabolic effects depend on several aspects ranging from chemical structure to food matrix and food processing which are best captured by the combined consideration of dietary fiber, whole grain, glycemic index or load, and dietary sugar. In Northern and Central European diets, bread is a major carbohydrate source, however, beneficial metabolic effects of bread may be confined to bread rich in fiber, whole grain and/or with a low glycemic index (GI) only.
The consortium consisting of 5 partners from Germany, Sweden and Norway will investigate the glycemic effects of bread, and the effects of whole grain consumption on body weight and diabetes risk in adults and in children, in order to achieve the main objectives of the consortium. These are:
- the generation of novel evidence on the relevance of bread intake for glycemic control and weight management among vulnerable populations
- to explore and clarify potential mechanisms and relations of bread intake with glycemic control and weight management
- to contribute to a healthy environment by exemplified advances in the infrastructure from food production to consumers
- to establish sustainable scientific networks
These objectives will be reached by
- a randomized multicenter study on the glycemic effects of bread with added beta-glucan. The bread will be specifically produced for this study.
- analysis of biomarkers of whole grain consumption in cohorts of adults (HUSK Norway) and children (Life Child, Leipzig)
- analysis of whole grain intake (dietary intake data and biomarker data) and its association with body weight and diabetes in adults and children
- Meta-analyses on the glycemic effects of breads with and without functional ingredient, and the effects of bread consumption on weight change
- collaboration among food producers, food scientists, nutritionists, and health personal
- establishing a network of early career scientists and senior scientists in the consortium
Results are expected towards the end of the funding period. It is expected that the results will be used to refine and elaborate dietary guidelines, for example in the 'Nordic Nutrition Recommendations (which are currently updated), and the D-A-CH dietary recommendations for the German speaking countries. Whole grain consumption is below the recommendations in large parts of the population. In addition, there is a great need for more specific data on the health effects of whole grain consumption. The results of the consortium and especially the clinical trial will provide the scientific basis for the development of breads with functional ingredients that fulfill EFSA health claims. On the long term, we expect to develop high fiber breads with high consumer acceptability which may increase whole grain and fiber intake.
|University of Paderborn
|University of Leipzig
|University of Chalmers
- The multicenter study (WP1) is running according to protocol in all centers (finished in Paderborn by mid 2022, ongoing in Leipzig, Bergen and Gothenborg). The study is epected to be finished in late spring 2023 and will achieve the proposed number of recruited participants with pre-diabetes.
- The consortium put a lot of efforts in developing a common protocol to ensure similar recruitment of participants and execution of the study, by use of common standard operation procedures (SOPs) and all using the same bread. These efforts resulted in a protocol paper which was published in BMJOpen in summer 2022: Hjorth T, Schadow A, Revheim I, Spielau U, Thomassen LM, Meyer K, Piotrowski K, Rosendahl-Riise H, Rieder A, Varela P, Lysne V, Ballance S, Koerner A, Landberg R, Buyken A, Dierkes J. Sixteen-week multicentre randomised controlled trial to study the effect of the consumption of an oat beta-glucan-enriched bread versus a whole-grain wheat bread on glycaemic control among persons with pre-diabetes: a study protocol of the CarbHealth study. BMJ Open. 2022 Aug 23;12(8):e062066. http://dx.doi.org/10.1136/bmjopen-2022-062066
- In the adult cohort study (WP2) the measurements of alkylresorcinols in biological samples have been finalized. AR data were analyzed for assoications with whole grain intake and cardiovascular risk factors (such as lipids, blood pressure, body compositon) in the HUSK cohort cross-sectionally. Correlations with cardiovascular risk factors were stronger in men than in women, and we observed significant negative correlations of AR with LDL-cholesterol and body fat. Currently, the publication of results is prepared and expected to be submitted before the summer break.
- In the childrens cohort (WP3) the additional measurements of alkylresorcinols (baseline) have been finished and data will be provided soon for further calculation of results.
- The systematic review and meta-analysis (WP4) evaluated the effect of regular consumption of reformulated breads on glycemic control among healthy adults, adults at cardiometabolic risk or with manifest T2DM. Twenty-two studies met the inclusion criteria (n=1037 participants). Compared to ‘regular’ or comparator bread, consumption of reformulated intervention breads yielded lower fasting blood glucose concentrations, yet no differences in fasting insulin, HOMA-IR, HbA1c or postprandial glucose response. Subgroup analyses revealed a beneficial effect for fasting blood glucose only among people with T2DM (low certainty of evidence).
- The first meta-analysis has been published: Schadow AM, Revheim I, Spielau U, Dierkes J, Schwingshackl L, Frank J, Hodgson JM, Moreira-Rosário A, Seal CJ, Buyken AE, Rosendahl-Riise H. The Effect of Regular Consumption of Reformulated Breads on Glycemic Control: A Systematic Review and Meta-Analysis of Randomized Clinical Trials. Advances in Nutrition. 2022. https://doi.org/10.1016/j.advnut.2022.10.008.
Author: Hjorth T, Schadow A, Revheim I, Spielau U, Thomassen LM, Meyer K, Piotrowski K, Rosendahl-Riise H, Rieder A, Varela P, Lysne V, Ballance S, Koerner A, Landberg R, Buyken A, Dierkes J.
Author: Schadow AM, Revheim I, Spielau U, Dierkes J, Schwingshackl L, Frank J, Hodgson JM, Moreira-Rosário A, Seal CJ, Buyken AE, Rosendahl-Riise H.