Objective: To determine if it is possible to deliver a one-quarter reduction in the sodium content of bread without detection.
Design: Single-blind, randomized, controlled trial.
Setting: The Royal North Shore Hospital in Sydney, Australia.
Participants: One-hundred and ten volunteers from the hospital staff that completed 94% of scheduled assessments.
Intervention: Six consecutive weeks of bread with usual sodium content or six consecutive weeks of bread with cumulating 5% reductions in sodium content each week.
Main outcome measure: The proportion of participants reporting a difference in the salt content of the study bread from week to week.
Results: The intervention group were no more likely than the control group to report a difference in the salt content of the bread from week to week (P=0.8). Similarly, there were no differences between randomized groups in the scores for flavour (P=0.08) or liking of the bread (P=0.95) over the study follow-up period. However, the saltiness scores recorded on a visual analogue scale did decline in the intervention group compared with the control group (P=0.01)
Conclusions: A one-quarter reduction in the sodium content of white bread can be delivered over a short time period, while maintaining consumer acceptance. Over the long term, and particularly if achieved for multiple foods, a decrease in sodium content of this magnitude would be expected to reduce population levels of blood pressure and the risks of stroke and heart attack.