Experts argue salt is not as bad for health as you think

Is it time to shake up the rules on salt? Experts argue it’s not as bad for health as you think

The official advice is clear — too much salt is bad for you. It raises your blood pressure and increases your chances of developing cardiovascular disease and having a potentially fatal stroke or a heart attack.

The theory goes that excess salt in your system leads to water retention in the blood, putting pressure on your blood vessels, raising your blood pressure.

To reduce that risk, says the Government, adults should aim to consume less than 6g of added salt a day, just over one teaspoonful.

Not easy when you consider that two slices of bread alone provide 1g before you add fillings or flavourings.

The World Health Organisation goes further — it says 2.5 million deaths could be prevented each year globally if salt consumption were reduced to less than 5g a day for adults, a target that all member states, including the UK, have committed to achieving by 2025.

Now, the National Food Strategy, the independent review of the UK food system (headed by Henry Dimbleby of the Leon chain) that is being published this week, is apparently proposing a 6 per cent tax on salty foods such as processed meat.

But there are questions being raised about the idea that salt is indeed bad for us all, particularly following a study published in the European Heart Journal recently that drew a conclusion even its lead author — previously a passionate supporter of reducing our intake — describes as ‘startling’.

In a nutshell, it found that with an intake up to between 10g to 12.5g a day — twice the limit currently recommended in the UK — life expectancy actually increases.

It’s a conclusion that turns the ‘salt is bad for you’ orthodoxy on its head, and when Good Health spoke to Professor Franz Messerli, a cardiologist at the Swiss Cardiovascular Centre at Bern University in Switzerland who led the study, his surprise at his own findings was palpable. ‘All my life I, too, was a salt-reduction evangelist,’ he told Good Health.

‘I always told my patients and I have published papers saying whether you have high blood pressure or normal blood pressure, you should reduce your salt intake.’

Then, in 2018, Professor Messerli was invited to write an editorial for The Lancet, commenting on a paper by Canadian researchers who had monitored 94,378 adults aged 35 to 70 years from 18 countries for eight years.

The researchers found that salt intake was associated with cardiovascular disease and strokes, but only in communities where consumption was in excess of 12.5g of salt a day.

They concluded that ‘a strategy of sodium reduction in these communities and countries but not in others might be appropriate’.

The paper’s findings, Professor Messerli told Good Health, forced him to challenge his beliefs. ‘I asked myself, ‘What is the advice we give about salt really based on?’,’ he said. ‘I had no evidence that convinced me this was a good idea, so I said to my colleagues, ‘Look, if salt is indeed a culprit of cardiovascular disease and mortality, then a high salt intake should be detrimental. So let’s look at the correlation between life expectancy, mortality and salt intake around the world.’ ‘

Professor Messerli and colleagues in Poland, Switzerland and the U.S. compared salt consumption and life expectancy in 181 countries. Salt consumption figures were obtained from research published in the journal BMJ Open in 2013 by the international Global Burden of Diseases Nutrition and Chronic Diseases Expert Group.

Since dietary salt intake was widely seen as a risk factor for cardiovascular disease and premature death, it was expected that a diet high in salt would shorten lifespans.

But ‘to our great surprise’, the researchers discovered that life expectancy actually increased with greater salt consumption.

The research offers no clue why this should be the case. But Professor Messerli and his colleagues concluded that their finding ‘argues against dietary sodium intake being a culprit of curtailing lifespan or a risk factor for premature death’.

Professor Messerli stops short of making recommendations based on his findings. He told Good Health: ‘I hate to have a paper without a take-home message, but it is extremely difficult to make a recommendation. I don’t know if we can say you can save lives by increasing salt intake, although the paper seems to show that.’

But some facts, he adds, are hard to ignore. ‘If you look at the population that has the highest life expectancy in the world, it is women in Hong Kong. They live an average of 87 years, and these women, who average 56kg [around 8½ stone] in weight, eat 9g of salt per day, about 1g more than the average person in the UK.

‘If you adjust the intake for the body weight, they eat about twice as much as the average American man, and yet live distinctly longer.’

The research appears to support the claims made in 2017 by Dr James DiNicolantonio, a U.S. cardiovascular research scientist, in his book The Salt Fix.

Since dietary salt intake was widely seen as a risk factor for cardiovascular disease and premature death, it was expected that a diet high in salt would shorten lifespans

After reviewing more than 500 papers on salt consumption, blood pressure and heart disease, he concluded that ‘the vast majority of us don’t need to watch our salt intake. In fact, for most of us, more salt would be advantageous for health.’

Dr DiNicolantonio found that ‘approximately 80 per cent of people with normal blood pressure [i.e. less than 120/80 mmHg] are not sensitive to the blood pressure-raising effects of salt at all.

‘Even among those with full-blown hypertension, about 55 per cent are totally immune to salt’s effects on blood pressure’.

As he told Good Health last week: ‘Many things deplete the body of salt, such as exercise, caffeine, medications and numerous diseases. To have blanket recommendations to go on a low-salt diet is not conducive to many people.

‘If exercise is one of the best things that we can do for our health and we lose salt through sweat, then we shouldn’t be telling people to exercise and at the same time limit their salt intake. This can lead to salt deficiency.

‘Furthermore, a lack of salt has been shown to increase heart rate, stress hormones and insulin levels — to think that a small reduction in blood pressure (which may or may not occur with salt restriction) would outweigh these harms is a big assumption.’

The work of both men feeds into a debate that has divided medical opinion for decades — the suggestion that a small proportion of people are ‘salt sensitive’, while the majority are largely immune to its negative effects.

One of the UK’s leading epidemiologists (who studies the causes of disease) concurs, and challenges what he calls the ‘salt police’.

In Spoon-Fed: Why Almost Everything We’ve Been Told About Food Is Wrong, Tim Spector, a professor of genetic epidemiology at King’s College London, says: ‘Nobody is average. Yet everything in medicine and nutrition has been dumbed down to the idea that there is an average person, male and female, that this is the average amount they need, and that this is what their average response will be. It’s the same with salt. A small proportion of people will respond strongly to changes in their intake — but others won’t at all.’

Professor Spector told Good Health: ‘It all comes down to nobody being average: the average is made up of the ones that do and the ones that don’t respond to changes in their salt intake, but within that there is a huge range of responses, and all of us are likely to respond to salt very differently.’

He says there is ‘growing evidence that some people respond much more strongly to salt than others, and are known as salt sensitive’, but he admits it is a ‘controversial’ theory.

Controversial — but increasingly accepted. In 2016 the American Heart Association published a statement on salt sensitivity that highlighted research that ‘strongly suggests’ it might be caused in humans by genetic variations.

One study of more than 74,000 Europeans, published in the journal Nature Genetics in 2011, identified six separate ‘genetic mechanisms underlying blood pressure variation’.

But identifying who is salt-sensitive poses a real challenge. While there was now no doubt that salt ‘plays a meaningful role’ in causing high blood pressure, ‘we have still not fully explained the link between . . . blood pressure and salt sensitivity’, the authors of another paper, published last year in the Journal of Human Hypertension, concluded. The problem is that the condition of salt sensitivity ‘cannot be used by the physician in everyday patients’ care, mainly owing to a lack of a simple and practical diagnostic test’.

What we need, adds Professor Spector, is ‘a very individual, personalised approach to nutrition, rather than one-size -fits-all’.

But in the meantime, he argues, for most people, the reduction in blood pressure as a result of cutting back is ‘surprisingly small and clinically trivial’.

Professor Spector cites a review of 185 studies published in 2017 in the Cochrane Database of Systematic Reviews, which found that, in his words, ‘for people with normal blood pressure, reducing their salt intake to one-and-a-quarter teaspoons per day [around 7g] resulted in a very small reduction — just 2 per cent — in systolic blood pressure’ — the pressure in blood vessels when the heart is contracting.

Such a small amount ‘may make you question whether a life following a salt-free, tasteless diet is really worth it’, concluded Professor Spector.

As long as we eat a sensible, well-balanced diet and go easy on junk food, such as burgers, pizza and crisps, most of us can enjoy our food without guilt — and should take the current salt guidelines ‘with a reasonably large, and surprisingly healthy, pinch of salt’, he suggests.

So should we do just that?

‘Absolutely not,’ says Graham MacGregor, a professor of cardiovascular medicine at Barts and The London who, as the founder of Action on Salt, has spent much of the past two decades successfully campaigning for tougher salt guidelines.

‘The statement that reducing salt intake causes only a small fall in blood pressure in the population shows a fundamental lack of understanding of epidemiology,’ he says.

Regardless of whether certain individuals might be salt-sensitive, he says lowering salt consumption across the entire population can only save lives.

There is, Professor MacGregor told Good Health, no doubt that ‘small changes in salt intake across the whole population have a huge impact’.

This was first demonstrated by Professor Geoffrey Rose, an epidemiologist at the London School of Hygiene and Tropical Medicine. In the groundbreaking INTERSALT study, Professor Rose and colleagues looked at the relationship between blood pressure and the levels of salt excreted in urine over 24 hours in more than 10,000 participants in 52 centres around the world.

The results, published in The BMJ in 1988, ‘quite clearly showed that a 2mm fall in blood pressure across a whole population prevented more strokes and heart attacks than controlling people with high blood pressure with medication’, says Professor MacGregor.

There have been other, similar findings, including a review published last year by Professor MacGregor and colleagues (with 133 trials involving more than 12,000 people), which found that reducing salt intake lowered blood pressure across the population, including those with normal blood pressure.

And the greater the reduction in salt, the greater the fall in blood pressure.

In 2003, Professor MacGregor’s group and the Food Standards Agency developed a programme of voluntary salt reduction with the food industry. An analysis in 2008 found that salt reduction campaigns in the UK led to around 6,000 fewer deaths a year from cardiovascular disease.

What are the salternatives?

Salt ‘replacements’ offer an alternative to those who want to cut their intake. Here, dietitian Helen Bond assesses some of the most popular salt alternatives, which we then rated.

Potassium substitutes

For example: Lo Salt, 350g, £1.70, sainsburys.co.uk

Standard salt (table, sea or rock) is chemically 100 per cent — or very close to 100 per cent — sodium chloride.

But in ‘low-salt’ products such as this one, up to two-thirds of the sodium part is replaced by potassium, another mineral that tastes ‘salty’. Potassium is lacking in many people’s diets (17 per cent of UK adults have intakes that put them at risk of deficiency), and it is needed for healthy muscles and nerves — and for normal blood pressure.

A quarter teaspoon serving of Lo Salt contains 450mg potassium — 23 per cent of an adult’s daily amount.

However, some of these potassium-based substitutes can still be up to 50 per cent sodium chloride. Also, if you have kidneys that do not function well (because of diabetes, for example), too much potassium may be harmful, so check with your doctor first.

3/5

Salt-free herb blends

For example: Dash Salt Free Original, 71g, £6.44, amazon.co.uk

Typically, a combination of garlic, onion and tomato powder, with pepper and other herbs and spices — but no salt. The idea is that this is full-flavoured enough so you can manage without adding salt. There aren’t any health downsides.

5/5

Herb salts

For example: Herbamare Original 250g, £3.85, avogel.co.uk

These contain sodium chloride but about 10 to 30 per cent less than standard table salt, combined with dried herbs and spices — celery salt and garlic salt are both examples. But salt is still usually the first ingredient.

2/5

Seaweed seasoning

For example: Seaspoon Seaweed Boost, 30g, £5.95, seaspoon.com

These are types of dried seaweed, such as sea spaghetti and dulse, crushed into granules or flakes for sprinkling. Usually free from added salt, they provide a good source of iodine, a mineral many people lack.

A half-teaspoon serving of Seaspoon Seaweed Boost provides your daily intake of iodine along with 5 to 9 per cent of your daily needs of magnesium and iron, needed for energy. If you have a pre-existing thyroid problem, avoid seaweed seasoning as you may end up with too much iodine.

4/5

Nutritional yeast

FOR EXAMPLE: Marigold Super Engevita Yeast Flakes, 100g, £3.50, tesco.com

This is a mildly cheesy flavouring made from dried yeast. It works well over vegetables, baked potatoes or popcorn. It’s virtually sodium-free and a tablespoon serving has up to the recommended daily amount of several B vitamins important for energy.

5/5

Angela Dowden

‘I’m an epidemiologist so I do understand that if you got everybody to halve the salt they’re eating you would have less of a problem with blood pressure and probably have fewer cases of stroke and heart disease,’ says Professor Spector.

‘The danger is when you apply that to an individual, the individual benefit is generally tiny.’

Professor Spector tried an experiment on himself which, he says, proved his point. ‘I developed high blood pressure ten years ago. I tried cutting out salt and it made very little difference. I realised for me it just wasn’t worth it.’

He decided to lose weight. ‘I was about 10kg heavier than I am now, and I went from 84kg [over 13st] to 74kg [11½st]. It’s not a huge change, but these things affect your blood pressure more than the salt does, and this is why I’m generally against this obsession with one item of our nutrition.

‘A far better way to get your blood pressure and your risk factors down is to do more exercise and lose weight.’

Official figures show adults aged 19 to 64 in the UK get most of their salt — roughly 29 per cent — from cereals, followed by meat products (27 per cent).

Under the latest voluntary salt-reduction targets for manufacturers, by 2024 salt in bacon, for example, should be cut from the previous target of 2.88g per 100g to 2.59g; the target for breakfast cereals has been cut from 0.59g to 0.48g.

Such incremental changes go unnoticed, says Professor MacGregor — ‘people’s salt intake has fallen and they don’t realise it because their salt taste receptors adjust’.

Despite such initiatives, the latest figures show that men in England are consuming 9.2g of salt a day and women, 7.6g.

This, said Action on Salt, meant that ‘the Government must now force the food industry to take out the huge and unnecessary amount of salt they add to our food’.

The salt tax reportedly now being proposed could mean that the Government will soon be doing just that.

Can you run up the stairs?

Yes — two at a time. I aim to exercise in some way every day (at the gym or, during lockdown, at home using a Swiss ball and bench) and I use a bicycle most of the time.

How has the pandemic affected you?

I feel I’m one of the lucky ones. I have a big house with a garden and the lockdown gave me licence to stay home with my family, play with my two youngest and work from home on the product side of my business.

Get your five a day?

My partner Kelly [a fashion designer and hairdresser] and I eat well. I love vegetables and salads, and because of my Greek background there’s always a soup on the go full of veg and pulses.

Ever dieted?

Not really, but I fluctuate and if my clothes feel tight I cut down on the carbs and sweet things. I am 5 ft 11 in and three-quarters (I like my three-quarters) and weigh between 12 st 7 lb and 13 st 7 lb.

Any vices?

I like a couple of glasses of wine or gin and tonic every day. Other weaknesses are bread, cheese and chocolate.

Any family ailments?

No — MY father died when he was 87 and it was a big shock because he was a very healthy, dynamic figure, had all his hair and was very active and just suddenly had a stroke. My Greek mother is very well and is now 98.

Worst illness or injury?

I had an abscess on my liver five years ago — caused by contaminated water that I had drunk in Turkey — and was in hospital for two weeks. Then two years ago I fell off my motorbike and broke both hands. I was worried it might affect my work but they have healed.

Pop any pills?

I am not a huge believer in vitamins, as I genuinely eat very well, but I do take vitamin D, magnesium and amino acids daily to preserve my muscle-mass as I grow older.

Had anything removed?

Part of my thyroid gland, two years ago. It kept becoming enlarged and was pressing on my windpipe — then they found some microscopic cancer cells so removed it. I took some chemo-type radioactive pills for a short time and that was it.

Ever have plastic surgery?

I would if I thought it was going to be absolutely brilliant but I’m so terrified of how bad it could be that I’m put off.

Any phobias?

I’m not keen on rats.

Like to live for ever?

Maybe not for ever, but for a very long time. It will be interesting to see how life evolves — hopefully in ever more positive ways. I’m saddened that in the 21st century there are so many wars.

Find out more about Nicky’s new Azure hair-care range at nickyclarke.com

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