Carbohydrates and Health

cohort studies were identified in the update search (Sluijs et al., 2010; Hopping
et al., 2010; Sakurai et al., 2012) (Cardio-metabolic review, diabetes and glycaemia
chapter; Update search).
8.19 An association is indicated between higher consumption of dietary fibre and
a reduced incidence of type 2 diabetes mellitus (RR 0.94, 95% CI 0.90, 0.97 for
each 7g/day increase; p=0.001). Two of the studies identified in the update search
indicate higher dietary fibre intake is associated with a reduction in the incidence
of type 2 diabetes mellitus (Sluijs et al., 2010; Hopping et al., 2010) and the other
study indicates no statistically significant association between dietary fibre intake
and the incidence of type 2 diabetes (Sakurai et al., 2012).
Dietary fibre (g/day) and type 2 diabetes mellitus
• Association
• Adequate evidence
• The direction of the association indicates a higher consumption of dietary fibre is
beneficial to health
• The association is biologically relevant
Fasting blood glucose
8.20 Four randomised controlled trials were identified that presented evidence on
dietary fibre in relation to blood glucose, all of which were included in a metaanalysis
(Aller et al., 2004; Thompson et al., 2005; Andersson et al., 2007; Olendzki
et al., 2009). One trial was subsequently identified in the update search (Venn et al.,
2010) (Cardio-metabolic review, diabetes and glycaemia chapter; Update search).
8.21 The heterogeneity is above the pre-specified cut-off of 75% (I 2 =82%) and, therefore,
the pooled estimate has not been reported. No consistent effect is demonstrated
for dietary fibre intake on fasting blood glucose concentration in the forest plot.
The trial identified in the update search demonstrates no significant effect of
dietary fibre intake on fasting blood glucose concentration.
Dietary fibre and fasting blood glucose concentration
• No effect
• Limited evidence
Fasting insulin
8.22 Three randomised controlled trials were identified that presented evidence
on dietary fibre in relation to fasting insulin concentration (Aller et al., 2004;
Thompson et al., 2005; Andersson et al., 2007). No further trials were identified
in the update search (Cardio-metabolic review, diabetes and glycaemia chapter).
8.23 Due to variation between the different methodologies used to measure fasting
insulin concentration, it was not possible to conduct a meta-analysis. All trials
report no significant effect of dietary fibre on fasting insulin concentration.
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