Thursday August 7 2014
Many cheeses have a higher salt content than seawater
"Halloumi and blue cheese saltier than seawater,” reports The Daily Telegraph, following the publication of research on the salt content of cheeses sold in the UK.
Researchers looked at 612 supermarket cheeses and found that salt levels were high. They also found a wide variation in salt content within the same types of cheese.
Halloumi and imported blue cheese contained the highest average amount of salt (2.71g/100g), more salty than seawater (2.5g/100g), whereas cottage cheese contained the lowest average amount of salt (0.55g/100g).
Some types of cheddar – Britain’s best-selling cheese – had much higher levels of salt than others, with supermarket own brands having lower average levels than branded counterparts.
Cheese is one of the top 10 sources of salt in our diet and is widely consumed, with the average person eating 9kg of cheese a year.
Eating too much salt can cause high blood pressure, which can lead to heart disease, stroke and chronic kidney disease.
However, salt is an integral part of the cheese-manufacturing process. It controls moisture, texture and functionality, and also controls microbial growth.
The government has issued voluntary salt targets for specific categories of cheese, to encourage manufacturers to lower their salt content.
This study found that 84.5% of the cheeses in these categories have achieved their target. Unsurprisingly, it found that cheeses without a target had a higher salt content.
Researchers say the salt content in cheese is “unnecessarily high” and are calling for “more challenging salt reduction targets to be set”.
Where did the story come from?
The study was carried out by researchers from the Centre for Environmental and Preventive Medicine at Barts, and the London School of Medicine and Dentistry. All researchers are employees, members or the chairman of Consensus Action on Salt and Health (CASH), a non-profit organisation set up in 1996. The study reports that it did not receive funding from any funding agency in the public, commercial or not-for-profit sectors.
The study was published in the peer-reviewed medical journal BMJ Open. It is free to read on the journal's website.
The media’s coverage of the study was generally accurate.
What kind of research was this?
This was a cross-sectional survey looking at the salt content of different cheeses sold in UK supermarkets. It aimed to assess whether the salt content had fallen since the government set voluntary targets for some types of cheese.
Eating too much salt puts pressure on the kidneys and can cause high blood pressure. This can lead to heart disease, stroke and chronic kidney disease. High salt intake has also been linked to increased risk of stomach cancer and osteoporosis.
Adults should have no more than 6g of salt per day, according to UK recommendations, although the World Health Assembly has agreed that the target should be for people to consume up to just 5g per day. Current UK consumption levels stand at 8.1g per day. Salt content over 1.5g per 100g in any food is considered high, according to government guidance.
Many cheeses are known to have a high salt content, and on average, the report states that people in the UK consume 9kg of cheese per year. It is therefore important to know which cheeses have a high salt content, so they can be eaten sparingly as part of a balanced diet.
What did the research involve?
The researchers surveyed all available cheeses from seven main supermarket chains in the UK by each visiting one large shop. The supermarkets were Asda, Marks & Spencer, Sainsbury’s, Tesco, The Co-operative and Waitrose. Due to resource limitations, only cheddar cheese and cheddar-style cheese products were collected from Morrisons.
They recorded the product name, sodium/salt per 100g, serving size and sodium/salt per portion from the label of each cheese. They categorised and analysed them according to 23 types of cheese, their country of origin, their brand and whether they were on the UK Department of Health's cheese salt reduction target list.
They excluded any cheese that did not have a sample size of at least eight products containing nutrient information on the packaging. This included Jarlsberg, mascarpone, Lancashire, Leerdammer, Maasdam, sheep, Appenzeller, Bavarian smoked and ricotta.
What were the basic results?
A total of 612 cheeses were included in the analysis. Halloumi and imported blue cheese had the highest average salt level (2.71g/100g) – saltier than seawater (2.5g/100g) according to CASH – followed by some processed cheeses (2.48g/100g). Cottage cheese had the lowest (0.55g/100g).
There was a wide variation in salt content within each category of cheese, and this was particularly marked for parmesan, imported blue cheeses and Emmental.
Cheeses with salt targets had lower levels of salt than those without, and of the 394 cheeses that have voluntary cheese targets, 84.5% have already met their 2012 target.
The salt content of supermarket own-brand cheese was compared with branded cheese for 10 categories of cheese, and researchers found that:
- Six classes of cheese had higher salt content in branded products than the supermarket's own brand.
- Four classes of cheese had a higher salt content in the supermarket's own brand compared to a branded version.
How did the researchers interpret the results?
“Cheese is unnecessarily loaded with salt,” researchers said in an editorial released with the study. They state in their report that “salt content in cheese in the UK is high. There is a wide variation in the salt content of different types of cheeses and even within the same type of cheese”. Even though 84.5% cheeses are within the voluntary salt targets, researchers say their findings “demonstrate that much larger reductions in the amount of salt added to cheese could be made and more challenging targets need to be set, so that the UK can continue to lead the world in salt reduction”.
This study highlights the wide variation in salt content that can be found in cheese. Labelling is now making it easier to make an informed choice regarding where you wish your maximum recommended level of 6g of salt per day to come from. This is particularly important when assessing which cheese is the best option for children, who should consume lower levels of salt.
The study showed that there were many types of cheese that have a reasonably low salt content, including cottage cheese, cream cheese, mozzarella and Emmental. However, cheese is generally calorific, and overconsumption can lead to overweight and obesity and their associated health problems.
A limitation of this study is that the actual salt content was not independently assessed, but relied on the accuracy of the labels. The authors also acknowledge that they did not investigate how the reduction in salt has been achieved, and there is the possibility that it has been replaced by other additives or ingredients.
Analysis by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.