Manipulation of bread composition and the effects on cardiovascular disease risk factors
Background: Deaths due to cardiovascular disease are set to rise from 22 millionglobally in 2015 to a projected 112 million in 2030. Many dietary modifications havebeen shown to be beneficial for the prevention and management of cardiovascular diseaserisk. Therefore, many of these dietary changes are recommended by numerous healthorganisations to lower cardiovascular disease risk however, only a small percent of thepopulation make these changes. Previous research has shown that using bread, a staplein many parts of the world, as a means to changing consumption of certain foods and/ornutrients is both viable and acceptable. Unfortunately, the majority of these previousinterventions have been of short duration or have not included risk factors forcardiovascular disease as primary outcomes.Objective: To investigate the effect of consuming four different types of bread (controlwhite bread, beetroot-enriched bread, low sodium bread, nut-enriched bread) on markersof cardiovascular disease over 12 weeks.Design: A total of 92 participants were recruited from the general public in Dunedin totake 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). Participantswere randomly allocated to receive one of four breads for 12 weeks. Outcome measuresincluding body weight, plasma lipids and lipoproteins, blood pressure and pulse wavevelocity were taken at baseline and week 12.Results: There were no statistically significant differences in change from baseline toweek 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 pressurebetween groups there were some interesting differences in those participants consumingthe low sodium bread and the beetroot bread compared to baseline (-4.0/-6.0 mmHg insystolic blood pressure and -2.8/-3.5 mmHg in diastolic blood pressure).Conclusion: Consuming different breads, enriched with recommended servings of eitherbeetroot or nuts, or a reduced sodium content, did not significantly affect markers ofcardiovascular disease. While some measures, in particular blood pressure, showedclinically interesting effects, this was a partial analysis of a study still in recruitment, andthese results should be interpreted with caution.
Advisor: Black, Katherine; Brown, Rachel
Degree Name: Master of Science
Degree Discipline: Human Nutrition
Publisher: University of Otago
Keywords: Bread, hazelnuts, beetroot, nitrate, sodium, cardiovascular disease, blood pressure, lipids, lipoproteins, arterial stiffness, randomised control trial
Research Type: Thesis