Achieving the salt intake target of 6 g/day in the current food supply in free-living adults using two dietary education strategies

Abstract

There are national targets for salt intake of 6 g salt/day in Australia and the United States. Despite this, there is limited knowledge about the effectiveness of dietary education in reducing salt intake to this level. The objective of this study was to investigate whether dietary education enabled a reduction in salt consumption. In an 8-week parallel study, 49 healthy free-living adults were recruited from the Adelaide community by newspaper advertisement. In a randomized parallel design, participants received dietary education to choose foods identified by either Australia's National Heart Foundation Tick symbol or by the Food Standards Australia and New Zealand's low-salt guideline of 120 mg sodium/100 g food. Sodium excretion was assessed by 24-hour urinary sodium collections at baseline and weeks 4 and 8. Participants' experiences of following the education strategies were recorded by self-administered questionnaire. These data were collected between August and October 2008. Forty-three participants completed the study. After 8 weeks, urinary sodium excretion decreased from 121+/-50 to 106+/-47 mmol/24 hours (7.3+/-3.0 to 6.4+/-2.8 g salt/24 hours) in the Tick group and from 132+/-44 to 98+/-50 mmol/24 hours (7.9+/-2.6 to 6.0+/-3.0 g salt/24 hours) in the Food Standards Australia New Zealand group (P<0.05, with no between-group difference). Barriers to salt reduction were limited variety and food choice, difficulty when eating out, and increased time associated with identifying foods. In conclusion, dietary sodium reduction is possible among free-living individuals who received dietary advice.