Manipulation of bread composition and the effects on cardiovascular disease risk factors

Abstract

Background: Deaths due to cardiovascular disease are set to rise from 22 million globally in 2015 to a projected 112 million in 2030. Many dietary modifications have been shown to be beneficial for the prevention and management of cardiovascular disease risk. Therefore, many of these dietary changes are recommended by numerous health organisations to lower cardiovascular disease risk however, only a small percent of the population make these changes. Previous research has shown that using bread, a staple in many parts of the world, as a means to changing consumption of certain foods and/or nutrients is both viable and acceptable. Unfortunately, the majority of these previous interventions have been of short duration or have not included risk factors for cardiovascular disease as primary outcomes. Objective: To investigate the effect of consuming four different types of bread (control white bread, beetroot-enriched bread, low sodium bread, nut-enriched bread) on markers of cardiovascular disease over 12 weeks. Design: A total of 92 participants were recruited from the general public in Dunedin to take part in this randomised controlled parallel study with four arms: a control bread (standard white bread), low sodium bread (333 mg sodium per 120 g), a beetroot bread (1.4 mmol of nitrate per 120 g), and a nut bread (30 g hazelnuts per 120 g). Participants were randomly allocated to receive one of four breads for 12 weeks. Outcome measures including body weight, plasma lipids and lipoproteins, blood pressure and pulse wave velocity were taken at baseline and week 12. Results: There were no statistically significant differences in change from baseline to week 12 between groups for any measures of cardiovascular disease or body composition (all P > 0.05). While there were no statistically significant changes in blood pressure between groups there were some interesting differences in those participants consuming the low sodium bread and the beetroot bread compared to baseline (-4.0/-6.0 mmHg in systolic blood pressure and -2.8/-3.5 mmHg in diastolic blood pressure). Conclusion: Consuming different breads, enriched with recommended servings of either beetroot or nuts, or a reduced sodium content, did not significantly affect markers of cardiovascular disease. While some measures, in particular blood pressure, showed clinically interesting effects, this was a partial analysis of a study still in recruitment, and these results should be interpreted with caution.