A repeated cross-sectional study of socio-economic inequities in dietary sodium consumption among Canadian adults: implications for national sodium reduction strategies.

Lindsay Mclaren,Daniel J Dutton,Shayla Heidinger,Norman R Campbell,Valerie Tarasuk

doi:10.1186/1475-9276-13-44

Abstract

IntroductionIn many countries including Canada, excess consumption of dietary sodium is common, and this has adverse implications for population health. Socio-economic inequities in sodium consumption seem likely, but research is limited. Knowledge of socio-economic inequities in sodium consumption is important for informing population-level sodium reduction strategies, to ensure that they are both impactful and equitable.MethodsWe examined the association between socio-economic indicators (income and education) and sodium, using two outcome variables: 1) sodium consumption in mg/day, and 2) reported use of table salt, in two national surveys: the 1970/72 Nutrition Canada Survey and the 2004 Canadian Community Health Survey, Cycle 2.2. This permitted us to explore whether there were any changes in socio-economic patterning in dietary sodium during a time period characterized by modest, information-based national sodium reduction efforts, as well as to provide baseline information against which to examine the impact (equitable or not) of future sodium reduction strategies in Canada.ResultsThere was no evidence of a socio-economic inequity in sodium consumption (mg/day) in 2004. In fact findings pointed to a positive association in women, whereby women of higher education consumed more sodium than women of lower education in 2004. For men, income was positively associated with reported use of table salt in 1970/72, but negatively associated in 2004.ConclusionsAn emerging inequity in reported use of table salt among men could reflect the modest, information-based sodium reduction efforts that were implemented during the time frame considered. However, for sodium consumption in mg/day, we found no evidence of a contemporary inequity, and in fact observed the opposite effect among women. Our findings could reflect data limitations, or they could signal that sodium differs from some other nutrients in terms of its socio-economic patterning, perhaps reflecting very high prevalence of excess consumption. It is possible that socio-economic inequities in sodium consumption will emerge as excess consumption declines, consistent with fundamental cause theory. It is important that national sodium reduction strategies are both impactful and equitable.

Highlights

In many countries including Canada, excess consumption of dietary sodium is common, and this has adverse implications for population health
National data from France, Finland, Canada, the USA, the UK, Brazil, and Turkey [1] show that average daily sodium consumption in these populations all exceed, some by a large margin, both the 2,000 mg/day maximum recommended by the World Health Organization [2], and the 2,300 mg/day Tolerable Upper Intake Level (UL) previously recommended by the U.S Institute of Medicine [3]
The target population was residents of the ten provinces, excluding “Indians in bands and persons living in institutions and military camps” [38] and the sampling frame was a list of households based on the Canadian census

Summary

Introduction

In many countries including Canada, excess consumption of dietary sodium is common, and this has adverse implications for population health. Socio-economic inequities in sodium consumption seem likely, but research is limited. Knowledge of socio-economic inequities in sodium consumption is important for informing population-level sodium reduction strategies, to ensure that they are both impactful and equitable. Excess dietary sodium consumption is a significant concern in many countries, due to its common occurrence and health implications. National data from France, Finland, Canada, the USA, the UK, Brazil, and Turkey [1] show that average daily sodium consumption in these populations all exceed, some by a large margin, both the 2,000 mg/day maximum recommended by the World Health Organization [2], and the 2,300 mg/day Tolerable Upper Intake Level (UL) previously recommended by the U.S Institute of Medicine [3]. High blood pressure, which is directly linked with high sodium intake, is considered the leading preventable risk factor for death in the world [8]

Objectives

Methods

Results

Discussion

Conclusion