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Meta-Analysis
. 2017 Jul 19;9(7):769.
doi: 10.3390/nu9070769.

Whole Grain Intake and Glycaemic Control in Healthy Subjects: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Stefano Marventano  1 , Claudia Vetrani  2 , Marilena Vitale  3 , Justyna Godos  4 , Gabriele Riccardi  5 , Giuseppe Grosso  6
Affiliations
Meta-Analysis

Whole Grain Intake and Glycaemic Control in Healthy Subjects: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Stefano Marventano et al. Nutrients. .

Abstract

Backgrounds: There is growing evidence from both observational and intervention studies that Whole Grain (WG) cereals exert beneficial effects on human health, especially on the metabolic profile. The aim of this study was to perform a meta-analysis of randomised controlled trials (RCT) to assess the acute and medium/long-term effect of WG foods on glycaemic control and insulin sensitivity in healthy individuals.

Methods: A search for all the published RCT on the effect of WG food intake on glycaemic and insulin response was performed up to December 2016. Effect size consisted of mean difference (MD) and 95% CI between the outcomes of intervention and the control groups using the generic inverse-variance random effects model.

Results: The meta-analysis of the 14 studies testing the acute effects of WG foods showed significant reductions of the post-prandial values of the glucose iAUC (0-120 min) by -29.71 mmol min/L (95% CI: -43.57, -15.85 mmol min/L), the insulin iAUC (0-120 min) by -2.01 nmol min/L (95% CI: -2.88, -1.14 nmol min/L), and the maximal glucose and insulin response. In 16 medium- and long-term RCTs, effects of WG foods on fasting glucose and insulin and homeostatic model assessment-insulin resistance values were not significant.

Conclusions: The consumption of WG foods is able to improve acutely the postprandial glucose and insulin homeostasis compared to similar refined foods in healthy subjects. Further research is needed to better understand the long-term effects and the biological mechanisms.

Keywords: RTC; glycemia; healthy subjects; insulin; meta-analysis; whole grain.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
PRISMA flowchart indicating the results of the search strategy.
Figure 2
Figure 2
Forest plot of the meta-analysis carried out to investigate the effect of whole grain consumption on glucose iAUC. iAUC: incremental area under the curve; WWBc, whole-wheat cookies; WWBCr, whole-wheat crackers RK, rye kernels; WK, wholegrain wheat kernels; WGRB, whole grain rye bread; WGRB-lac, whole grain rye bread with lactic acid; WGRP, whole grain rye porridge; WLRB, wholemeal rye bread; WLRC, wholemeal rye crispbread; WKRB, whole kernel rye bread; WRB, Whole rye bread.
Figure 3
Figure 3
Forest plot of the meta-analysis carried out to investigate the effect of whole grain consumption on insulin iAUC. iAUC: incremental area under the curve; WGRB, whole grain rye bread; WGRB-lac, whole grain rye bread with lactic acid; WGRP, whole grain rye porridge; WKRB, whole kernel rye bread; WLRB, wholemeal rye bread; WLRC, wholemeal rye crispbread; WRB, Whole rye bread; WWBc, whole-wheat cookies; WWBCr, whole-wheat crackers.
Figure 4
Figure 4
Forest plot of the meta-analysis carried out to investigate the effect of whole grain consumption on maximal glucose and insulin response. WLRC, wholemeal rye crispbread; WLRB, wholemeal rye bread; WKRB, whole kernel rye bread; WGP, whole grain pasta; WKRB, whole kernel rye bread; WRB, Whole rye bread.
Figure 5
Figure 5
Forest plot of the meta-analysis carried out to investigate the effect of whole grain consumption on fasting glucose and insulin. WG, whole grain; HFW, high-fibre wheat; HFR, high-fibre rye.
Figure 6
Figure 6
Forest plot of the meta-analysis carried out to investigate the effect of whole grain consumption on HOMA-IR. WG, whole grain.
See this image and copyright information in PMC

References

    1. World Health Organization . World Health Statistics. World Health Organization; Geneva, Switzerland: 2009.
    1. Slavin J.L. Why wholegrains are protective: Biological mechanisms. Proc. Nutr. Soc. 2003;62:129–134. doi: 10.1079/PNS2002221. - DOI - PubMed
    1. Seal C.J., Brownlee I.A. Whole-grain foods and chronic disease: Evidence from epidemiological and intervention studies. Proc. Nutr. Soc. 2015;74:313–319. doi: 10.1017/S0029665115002104. - DOI - PubMed
    1. Costabile A., Klinder A., Fava F., Napolitano A., Fogliano V., Leonard C., Gibson G.R., Tuohy K.M. Whole-grain wheat breakfast cereal has a prebiotic effect on the human gut microbiota: A double-blind, placebo-controlled, crossover study. Br. J. Nutr. 2008;99:110–120. doi: 10.1017/S0007114507793923. - DOI - PubMed
    1. Giacco R., Clemente G., Cipriano D., Luongo D., Viscovo D., Patti L., Di Marino L., Giacco A., Naviglio D., Bianchi M.A., et al. Effects of the regular consumption of wholemeal wheat foods on cardiovascular risk factors in healthy people. Nutr. Metab. Cardiovasc. Dis. NMCD. 2010;20:186–194. doi: 10.1016/j.numecd.2009.03.025. - DOI - PubMed