The study, published in the BMJ Open journal, paper is the first to monitor social inequalities following the national salt reduction programme and analysed salt intake data in Britain between 2000-01 and 2011 - finding that people from low socio-economic positions still eat more salt than those from higher socio-economic positions.
Led by Professor Francesco Cappuccio from the World Health Organization Collaborating Centre for Nutrition, based at Warwick Medical School, the authors of the study looked at the geographical distribution of habitual dietary salt intake in Britain and its association with manual occupations and educational attainments - both indicators of socio-economic position and key determinants of health.
"Whilst we are pleased to record an average national reduction in salt consumption coming from food of nearly a gram per day, we are disappointed to find out that the benefits of such a programme have not reached those most in need,” said Cappuccio.
“These results are important as people of low socio-economic background are more likely to develop high blood pressure (hypertension) and to suffer disproportionately from strokes, heart attacks and renal failure."
Commenting on the research findings, Katharine Jenner, campaign director at Consensus Action on Salt and Health (CASH) told FoodNavigator that by targeting everyday foods, the salt UK reduction programme 'is benefitting the entire population, including those less educated.'
"However, in order to reach those most in need more effectively, manufacturers who sell them the most products need to do a lot more," she added. "It is immoral to make the unhealthy option the cheaper or easier option; good quality nutritious food should be available for all.”
The researchers used the British National Diet and Nutrition Survey (2008-11), a national representative sample of 1,027 men and women aged 19-64 years living in Britain. Salt intake was assessed with a four-day food diary, assessing salt consumption from food. Salt added by consumers at the table and during cooking (discretionary salt) was not measured.
Cappuccio and his colleagues revealed a significant reduction in dietary salt consumption from 2000-1 to 2008-11 of 0.9g of salt per day - consistent with the total reduction in salt consumption of 1.4g per day reported nationally when also discretionary use of salt is taken into account.
However, dietary sodium intake varied significantly across socioeconomic groups, even when adjusting for geographical variations, they added.
“There was higher dietary sodium intake in people with the lowest educational attainment and in low levels of occupation,” wrote the researchers.
Indeed, those with no qualification had, on average, a 5.7% higher dietary sodium intake than the reference group, the team revealed.
"The diet of disadvantaged socio-economic groups tends to be made up of low-quality, salt-dense, high-fat, high-calorie unhealthy cheap foods,” warned Cappuccio.
“We have seen a reduction in salt intake in Britain thanks to a policy, which included awareness campaigns, food reformulation and monitoring. However, clearly poorer households still have less healthy shopping baskets and the broad reformulation of foods high in salt has not reached them as much as we would have hoped."
"In our continued effort to reduce population salt intake towards a 6g per day target in Britain, it is crucial to understand the reasons for these social inequalities so as to correct this gap for an equitable and cost-effective delivery of cardiovascular prevention," he concluded.
Source: BMJ Open
Published online, Open Access, doi: 10.1136/bmjopen-2014-005683
“Socioeconomic inequality in salt intake in Britain 10 years after a national salt reduction programme”
Authors: Chen Ji, Francesco P Cappuccio