A study has found that nearly 50 per cent of takeaway meals contain more salt than advertised – with some dishes containing more than the recommended daily guidelines.
Salt is essential for basic bodily functions, including balancing fluids and keeping muscles and nerves working smoothly, and the NHS advises that adults consume no more than 6g of the vital mineral per day.
However, a research team from the University of Reading, who looked at 39 takeaway meals from 23 outlets, found that some dishes contained 10g of salt – nearly double the daily UK recommended amount.
The food was bought from a mixture of local restaurants and national chains, such as KFC, Wagamama, McDonald’s, Greggs, German Doner Kebab, GBK, Burger King, Domino’s Pizza and Subway.
The team found that almost half of the foods examined in the survey, 47 per cent, exceeded their declared salt levels, with curries, pasta and pizza dishes often failing to match what the restaurants’ menus claim.
Of all the foods sampled, meat pizzas had the highest salt concentration at 1.6g per 100g, but it was pasta dishes that contained the most salt per serving.
They averaged 7.2g per serving, which is more than a full day’s recommended intake in a single meal.
One pasta dish tested by the team contained as much as 11.2g of salt.
Researchers looked at how much salt were in popular takeaway dishes (file photo)
Curry dishes showed the greatest variation, with salt levels ranging from 2.3g to 9.4g per dish.
Surprisingly, chips from fish and chip shops – where salt is typically only added after cooking and on request – had the lowest salt levels at just 0.2g per serving.
Chips from other outlets averaged 1g per serving.
The US Food and Drug Administration (FDA) recommends Americans cap their sodium intake at 2.3g per day.
The research, published in the medical journal PLOS One, was carried out to examine the accuracy of menu food labelling and to examine the variation in salt content between similar dishes.
Lead author Professor Gunter Kuhnle said: ‘We conducted this research because we suspected that many menu labels were inaccurate on salt.
‘It is very difficult for restaurants to provide accurate values without measuring each meal.
‘Variations in preparation methods, ingredients used and portion sizes mean food labels are often guess work.
‘It’s virtually impossible to know exactly how much salt is being added to your dinner.’
There was between 2.3g to 9.4g of salt per curry dish
However, there were some limitations with this study, with the researchers noting that the small sample size means that the findings cannot be generalised to the entire takeaway sector.
Furthermore, it has to be kept in mind that many of the outlets are franchises, plus there might be regional and vendor-specific differences in salt content.
Excess sodium is one of the biggest drivers of high blood pressure, with hypertension linked to half of heart attacks and strokes.
Research suggests reducing UK salt intake in line with official guidelines by 2030 could prevent around 135,000 new cases of heart disease in Britain.
Professor Gunter Kuhnle added: ‘Food companies have been reducing salt levels in shop-bought foods in recent years, but our research shows that eating out is often a salty affair.
‘Menu labels are supposed to help people make better food choices, but almost half the foods we tested with salt labels contained more salt than declared. The public needs to be aware that menu labels are rough guides at best, not accurate measures.’
When we eat too much salt, the kidneys compensate by pulling water from other tissue and organs to pump into the bloodstream and keep blood sodium levels balanced.
This extra volume puts pressure on artery walls – making them stiffer and narrower – while also making the heart work harder to pump blood around the body.
Chip shop chips contained the least salt due to preparation methods
Over time, this increases the risk of heart attack, stoke and heart failure – where the organ effectively tires out from all the hard work.
As many as one in three people living in the UK are estimated to have the condition, but it’s thought that five million could be living with it unknowingly – dramatically increasing their risk of a number of serious health conditions.
Because it causes no symptoms, many go undiagnosed until serious damage is done.
And while the link with heart disease is well established, salt’s potential impact on brain health – and dementia – is only now being unravelled.
Last year, data from more than 270,000 people registered on the UK biobank showed that those who ‘sometimes’ added salt to their food were 20 per cent more likely to suffer from depression than those who never added it to their meals.
Those who always added salt without fail were 45 per cent more likely to be depressed, according to the report published in the Journal of Affective Disorders.
It is also thought to increase the risk of anxiety, as excess inflammatory proteins disrupt the normal balance of chemicals that control mood in the brain.
A separate study, published in the same journal last year, found that those who consume more added salt are 19 per cent more likely to develop dementia.
It is not yet exactly clear what the link is, but high blood pressure is a known contributor to vascular dementia, which affects around 180,000 people a year in the UK alone.
