'Low-salt' Bread as a Means of Reducing Dietary Salt and Lowering Blood Pressure

Summary

In the context of public health, reformulation of bread in terms of salt content remains an important measure to help achieve a reduction in salt intake in the population. Therefore, the aim of this study was to examine, using a 5-week cross-over design, food-based intervention trial, the potential for inclusion of 'low-salt' bread as part of a pragmatic reduced-salt diet on blood pressure (BP) in adults with slightly to moderately elevated BP.

The study consisted of a randomized crossover trial of the effect of reduced-salt intake or usual-salt intake for 5 weeks on BP (as the primary outcome) in adults with slightly to moderately elevated BP (seated office systolic BP \>120 and \<160 mmHg or a diastolic BP \>80 and \<95 mmHg; identified by a pre-screening phase).

Subjects were randomly assigned to the reduced-salt diet or their usual-salt diet (control) for 5 weeks, followed by crossover to the alternative dietary regimen for a further 5 weeks. Subjects randomized to start on the reduced-salt diet were asked to restrict their consumption of dietary salt using a combination of pragmatic dietary advice as well as the replacement of bread and a limited number of other foods with equivalent foods which had lower salt content; these were provided to the participants. At the beginning of the salt restriction period, a research nutritionist provided the subjects with a list of the common salt-containing food and were asked to limit the consumption of such, as feasible. The subjects received in-house prepared 'low-salt (\<0.3 g/100 g)' brown or white sliced pan bread as well as no-salt margarine/butter, and were given luncheon meats with no added salt, if desired (optional); these were supplied regularly by the research staff. Subjects commencing the trial on the control diet were allowed to follow their usual diet but were asked to consume an in-house produced brown or white sliced pan bread equivalent in composition to the low-salt version but with its more typical salt content (1.2 g/100 g).

Participants met the research staff weekly to receive breads and no-salt margarine/butter as well as luncheon meats (where applicable), and at these meetings the staff promoted compliance with the intervention and encouraged completion of the study protocol.

BP and other assessments were made at baseline and at the end of week 5 and week 10.

Conditions

• Elevated Blood Pressure

Interventions

OTHER

Usual-salt diet

Subjects followed their usual-salt diet but were asked to consume an equivalent in-house produced brown or white sliced pan bread equivalent in composition to the low-salt version but with its more typical salt content (1.2 g/100 g).

OTHER

Reduced-salt diet

Subjects randomized to start on the reduced-salt diet were asked to restrict their consumption of dietary salt using a combination of pragmatic dietary advice as well as the replacement of bread and a limited number of other foods with equivalent foods which had lower salt content; these were provided to the participants. At the beginning of the salt restriction period, a research nutritionist provided the subjects with a list of the common salt-containing food (salted and naturally salty) and were asked to limit the consumption of such, as feasible. The subjects received in-house prepared 'low-salt (\<0.3 g/100 g)' brown or white sliced pan bread as well as no-salt margarine/butter, and were given luncheon meats with no added salt if desired (optional).

Sponsors & Collaborators

• University College Cork

  lead OTHER

Principal Investigators

• Kevin D Cashman, PhD · University College Cork

Study Design

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

SINGLE

Model

CROSSOVER

Eligibility

Min Age

18 Years

Max Age

65 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2008-01-03

Primary Completion

2010-07-30

Completion

2010-07-30

Countries

• Ireland

Study Locations