The findings show that just 38% of butter and margarine on the market meet the UK Department of Health's 2012 targets on salt - with seven out of ten butters surveyed containing salt levels that would land it in the red under traffic light labelling.
The survey analysed more than 300 products from all leading UK supermarkets, finding that 62% of ‘fats and spreads’ have failed to achieve the 2012.
CASH also highlighted that terms on the labels of butters and spreads can be deceptive - revealing that the salt content of varieties claiming they are ‘slightly salted’ often do not differ much from ‘salted’ or regular products.
"These products are targeting the health conscious shopper, who should expect these products to be lower in salt, when in fact they aren’t," said CASH in a statement.
UK supermarket chain Marks & Spencer was 'named and shamed' as one of the worst offenders for this practice - with its own-brand 'Softer Butter' (which is described as ‘slightly salted’) actually containing more salt than its own 'Salted Farmhouse Butter'.
"Companies need to stop misleading their customers into thinking a product is lower in salt or fat through their ‘reduced salt’ and ‘lighter’ labels, when this isn’t actually the case," said Kawther Hashem, Nutritionist at CASH.
Commenting on the findings, food and nutrition policy expert Professor Jack Winkler said he CASH findings draw attention to the fact that, despite the general success of the salt reduction programme, some of the targets for 2012 have still not been met.
"CASH thinks this is unsatisfactory. And so do I," said Winkler.
"One of the important innovations in this survey is that it challenges the misleading claims to healthiness that some companies put on some products," he added. "Marketing managers are sensitive to the health consciousness of consumers, including their awareness of salt issues, so they make modifications supported by on-pack claims to imply that theirs is a healthier variant."
"What CASH has done is demonstrate that some of these claims do not mean very much."
“Our love affair with butter is bad for our hearts, and not just because it is full of fat; we often spread it on toast, use it in baking or add it to our cooking without thinking how much salt it contains," commented Katharine Jenner, campaign director for CASH.
"One slice of buttered toast can contain more salt than a packet of crisps, so it’s worth looking at the label and choosing a lower salt or unsalted spread."
Indeed, the CASH survey found that the highest levels of salt were in Weight Watchers Dairy Spread - which contains 2.5g salt per 100g – "as salty per 100g as seawater!" said CASH.
The group contrasted this high level of salt to Lurpak Spreadable Lighter Unsalted, which contains no salt per 100g.
"Reduced levels of salt can clearly be done, as demonstrated by the many low and unsalted products," Hasham said.
"Salt is completely unnecessary in butter," added Professor Graham MacGregor, CASH chairman. "The good news is that unsalted varieties of butter are available from all supermarkets and brands, and lower salt spreads are available if you read the labels carefully."
The worst offenders for salt in butter and spreads are listed below. A portion has been standardised to 10g throughout:
High examples of Butter
1. Country Life Butter, 2g salt per 100g, 0.2g per portion
2. Essential Waitrose Salted Dairy Butter, 1.9g salt per 100g, 0.19g per portion
3. Simply M&S English Salted Butter, 1.75g salt per 100g, 0.18g per portion
4. Anchor Butter, 1.7g salt per 100g, 0.17g per portion
5. Asda English Salted Butter/Asda Smart Price Butter, 1.7g salt per 100g, 0.17g per portion
High examples of Margarines/Spreads;
1. Weight Watchers Dairy Spread, 2.5g salt per 100g, 0.25g per portion
2. Clover Lighter and Clover Spread, 1.8g salt per 100g, 0.18g per portion
3. Aldi Spread the Love, 1.7g salt per 100g, 0.17g per portion
4. Lidl Heavenly Butter Spread, 1.6g salt per 100g, 0.16g per portion
5. Marks & Spencer Touch of Butter, 1.6g salt per 100g, 0.16g per portion
Similarly, those with the 'best' salt levels were found to be:
Low examples of Margarines/Spreads;
1. Lurpak Spreadable Lighter Unsalted, 0g salt per 100g, 0g per portion
2. Lurpak Unsalted Spreadable, 0g salt per 100g, 0g per portion
3. Simply M&S Lower Fat Slightly Salted Spread, 0.75g salt per 100g, 0.08g per portion
4. Bertolli Light Made with Mild Olive Oil, 0.8g salt per 100g, 0.08g per portion
5. The Co-operative Spreadable Slightly Salted, 0.9g salt per 100g, 0.09g per portion