Carbohydrates and Health

Whole grains (serving/day) and hypertension
• Association
• Limited evidence
• The direction of the association indicates higher whole grains consumption is
beneficial to health
• The association is biologically relevant
Blood pressure
8.133 Three randomised controlled trials were identified that presented evidence on
whole grains intake in relation to blood pressure, all of which were included in
the meta-analyses for systolic and diastolic blood pressure (Davy et al., 2002b;
Howard et al., 2006b; Andersson et al., 2007; Tinker et al., 2008). Two publications
presented data from the same trial (Howard et al., 2006b; Tinker et al., 2008), and
the data from Howard et al. (2006b) were used in the meta-analysis. Two trials
were subsequently identified in the update search (Brownlee et al., 2010; Tighe
et al., 2010) (Cardio-metabolic review, incident hypertension and blood pressure
chapter; Update search). All trials compared whole grain diets to refined grain
control diets.
8.134 No significant effect is demonstrated for whole grains consumption on systolic
blood pressure (0.2 mmHg, 95% CI -1.6, 2.0; p=0.85). Of the trials identified in the
update search one reports no significant effect (Brownlee et al., 2010), and the
other reports higher whole grains consumption to reduce systolic blood pressure
(Tighe et al., 2010).
8.135 No significant effect is demonstrated for whole grains consumption on diastolic
blood pressure (-0.3 mmHg, 95% CI -0.9, 0.4; p=0.43). The two trials identified in
the update search report no significant effect of whole grains consumption on
diastolic blood pressure.
8.136 One trial, contributes 92% to the pooled estimate for systolic blood pressure and
97% for diastolic blood pressure (Howard et al., 2006b). This trial elicited a very
small increase in whole grains consumption (less than one serving per day) and
also resulted in weight loss differences between experimental groups.
Whole grains and systolic and diastolic blood pressure
• No effect
• Moderate evidence
Fasting blood lipids
8.137 Five randomised controlled trials were identified that presented evidence on whole
grains intake in relation to total cholesterol, LDL-cholesterol, HDL-cholesterol
and triacylglycerol concentration, all of which were included in a meta-analysis
(Saltzman et al., 2001; Davy et al., 2002a; Howard et al., 2006b; Andersson et al.,
2007; Kim et al., 2008). One study did not report data on LDL-cholesterol (Kim et
al., 2008). Two trials were subsequently identified in the update search (Tighe et
al., 2010; Brownlee et al., 2010) (Cardio-metabolic review, hyperlipidaemias and
135