In a presentation to delegates at last week’s SAAFoST Salt/Sodium Reduction Workshops, Dr Edelweiss Wentzel-Viljoen of North-West University, explained the contribution of different food to salt intake in SA, and how this data was used by the Department of Health (DoH) to select the categories of processed food targeted for proposed stepwise reductions over a five-year period.According to the Charlton Study - undertaken by the Chronic Diseases of Lifestyle Research Unit of the Medical Research Council (MRC) in Langa, Cape Town in 2005 - black, coloured and white people all had mean salt intakes of 7.8g, 8.5g and 9.5g respectively. This is much higher than the World Health Organisation’s recommendation of less than 5g of salt or 2,000mg of sodium per day for adults.
The researchers found that the food industry accounted for 55% of consumption; while table salt/cooking/salty condiments (discretionary salt) accounted for 45.5% (black), 32.8% (coloured) and 42.2% (white) of intake among the different ethnic groups.
Wentzel-Viljoen explained that these consumption patterns are very different to ones in the UK and Europe. A 2003 study in the UK found that table salt/cooking/salty condiments (discretionary salt) contributed 15%, natural salts 5%, and the food industry 80%. Consumption is quite similar in the rest of Europe with table salt/cooking/salty condiments (discretionary salt) contributing 15%, natural salts 10-11%, and the food industry 75%.
She showed data from seven different studies (1982-2010), which indicated that the top five food contributing to sodium intake among South African children, are white bread, brown bread, hard margarine, salty snacks, and breakfast cereals. For adults, it is slightly different: white bread, brown bread, hard margarine, soup/gravy powder, and atchaar.
The DoH’s main concern from a public health perspective is that excessive salt intake increases blood pressure, which in turn heightens a person’s risk to have a stroke or develop coronary heart disease and kidney disease. And it is estimated that there are about 6.3m people in SA living with high blood pressure - a condition that is generally poorly diagnosed and managed.
In the Charlton Study, the MRC and three food industry partners collaborated to reduce the salt content in brown bread, margarine, soup mix, stock cubes and a flavour enhancer; while simultaneously increasing nutrients known to be beneficial to blood pressure control, namely potassium, magnesium and calcium. The effects on blood pressure were then monitored over an eight-week period.
Wentzel-Viljoen said that the results indicated that reductions in salt in bread, margarine, soup mix and flavoured seasoning will reduce salt intake by 0.85g per day, and that lowering the sodium content of these food will reduce the population distribution of systolic blood pressure. “This will result in 7,400 fewer deaths due to cardiovascular disease and 4,300 less non-fatal strokes per year than in 2008. And could lead to a saving of approximately R300m per year due to the prevention of non-fatal strokes.”
She emphasized that because South Africans have a high (40%) discretionary salt intake, we need to develop a salt reduction policy that includes both a population education approach with new food-based dietary guidelines as well as an onus on industry to reduce salt in food.
The general consensus in the room seemed to be doubt that the DoH has the manpower and funding available for a consumer education programme, and that industry will need to partner with other organisations like the Heart and Stroke Foundation to raise awareness. - Nici Solomon