Turning salt into Public Enemy No.1

Hey, did you hear? It’s National Salt Awareness Week! Usually, such themed weeks are an opportunity for suppliers and producers to encourage us to consume more of whatever stuff they are promoting. With salt, it’s a little different.

Like a normal food-themed week, top chefs have been hired to give us their secrets on how to use the white crystalline stuff – and I don’t mean the substance they shove up their noses to keep them going during a 14-hour shift poaching sea bass and doing artistic things with risotto. No, this is all a lot more downbeat. ‘A high salt diet poses many health risks and I urge all chefs to consider how much salt they add to their dishes’, declares Gordon Ramsay, in a rare profanity-free moment. ‘Let’s all eat better by going easy on the salt’, enthuses top French stove botherer, Raymond Blanc (1).

In fact, media coverage over the past week might convince you that a misplaced gram of salt could be far more injurious to your health than a gram of badly cut Charlie, if considerably cheaper. For example, one widely reported story straight from the press team at Consensus Action on Salt and Health (CASH), Britain’s main salt-reduction campaign, explained the blood pressure-inflating properties of many meals from popular eateries. Teaming up with local trading standards officers, CASH found that 72 per cent of the main courses at 16 bastions of Britain’s proud food culture, including Café Rouge, Harvester and Pizza Express, contained more than three grams of salt – that’s half the recommended daily intake for adults (six grams) in just one course.

Some meals were even worse. At Old Orleans, the chicken fajitas contain an apoplexy-inducing 8.8 grams of salt per serving. It’s a wonder you can hear yourself think in the place over the sound of cerebral blood vessels popping. The CASH press release continues: ‘Old Orleans also serves wings and ribs with 7.6 grams of salt per portion. A Pizza Express American Hot pizza contains 7.5 grams of salt per portion and a Wagamama Ramen contains 7.2 grams of salt per serving. By comparison, a popular main meal at Beefeater of sirloin steak, grilled tomato, flat mushroom and chips contains only 0.4 grams of salt.’ Well, it does until it hits the table and the diner decides to carpet-bomb it with condiments in an effort to make it taste of something.

CASH explains on its website what all the fuss is about: ‘A blood pressure of greater than 140/90 mmHg [millimetres of mercury] is said to be high and, at this level, studies have shown that lowering blood pressure has a beneficial effect on reducing the likelihood of developing a stroke or heart attack.’ So far, so uncontroversial. ‘Any intervention therefore that would lower blood pressure in the general population, even by small amounts, is likely to be of immense benefit in preventing both strokes and heart attacks.’

And the intervention that CASH has in mind is a drastic cut in our salt intake. CASH says: ‘A large number of studies have been conducted, all of which support the concept that salt intake is the major factor increasing population blood pressure. The diversity and strength of the evidence is much greater than for other lifestyle factors – eg. weight reduction, lack of fruit and vegetable consumption, and lack of exercise. The evidence that links salt to blood pressure is as strong as that linking cigarette smoking to cancer and heart disease.’ (Emphasis added).

The problem is that while the dangers of high blood pressure are well established, the claim that ‘salt intake is the major factor increasing blood pressure’ needs to be taken with a very large pinch of… well, you guessed it. It is simply untrue that ‘all studies’ show that salt is dangerous.

As Gary Taubes noted in an effective review of the evidence for Science in 1999, ‘The (Political) Science of Salt’, while there is a prima facie case against salt – that is, it encourages the body to retain fluid, increasing the pressure in blood vessels – the evidence from clinical trials and epidemiological studies has never been remotely clear-cut. Taubes summarises the situation as follows: ‘The debate has devolved into an argument over whether extreme reductions in salt intake, perhaps impossible to achieve in the general population, can drop blood pressure by as much as one or two millimetres of mercury, and if so, whether anyone should do anything about it. For people with normal blood pressure, such a benefit is meaningless; for hypertensives, clinicians say that medications have a much greater effect at a cost of a few cents a day. But what works for the individual and what works for public health are still two different things.’

A review in the British Medical Journal in 2002 drew similar conclusions: ‘Intensive interventions, unsuited to primary care or population prevention programmes, provide only small reductions in blood pressure and sodium excretion, and effects on deaths and cardiovascular events are unclear. Advice to reduce sodium intake may help people on antihypertensive drugs to stop their medication while maintaining good blood pressure control.’ (2)

Contrary to what CASH – and endless government advice – would have us believe, the major studies on salt and blood pressure have been inconclusive. The best that can be said is that for those diagnosed with high blood pressure, there may be some small health benefit to reducing salt intake. For the rest of the population, cutting dietary salt will either have no effect or could even be harmful.

With all the negative coverage of the white stuff, you could be forgiven for forgetting that salt is essential to human life. Salt is crucial to the delicate balancing act of maintaining our bodies’ internal state at optimum levels. We lose a considerable amount of salt when we sweat. For those accustomed to hot weather, their bodies adjust by drastically reducing the amount of salt lost through perspiration. But for those travelling to hot countries from more temperate climes, vigorous activity can lead to sickness and even death. Loss of salt has also been suggested as a reason why so many elderly people die during heatwaves. The combined loss of water and salt makes the blood become more concentrated and more liable to clot. Heart attacks and most strokes are, essentially, blood clots (3).

While campaigners and health authorities demand that consumers and processed food producers cut back on salt so that we consume no more than six grams per day, the reality is that most populations around the world consume between six and 12 grams of salt per day. The only exceptions are where salt is in short supply. The country with the highest life expectancy in the world – Japan – has a high-salt diet. The consistency of salt intake suggests there is some physiological basis to this level of consumption. Yet it is commonly suggested that the impressively complex internal processes that regulate the balance of salt, water and myriad other substances in our bodies, developed over millions of years of evolution, should be replaced by a government target. The New Labour government in Britain is famous for telling us how to live our lives, but I prefer to trust my kidneys over the bean counters in Whitehall when it comes to the contents of my blood.

What should be really shocking – but isn’t – is that there has been so little debate about this issue. One-sided, pre-judged research has been allowed to win the day while the critics of the salt hypothesis have been roundly ignored lest they dilute the health message. This is not just a problem for public debate; the way that the research itself has been approached by many campaigning academics has been utterly one-sided. One Scottish expert describes this as the ‘Bing Crosby approach’ to science: ‘Accentuate the positive, eliminate the negative.’

If a few researchers had a bee in their bonnets about salt, it would be unlikely to matter to the rest of us. But this myth has government backing; like many other aspects of lifestyle, it fits in with a narrative which suggests that we are vulnerable individuals who need to be told by experts how to live our lives. And if we refuse to follow this advice from our superiors, we will become chronically ill and die. This is an insidious and authoritarian story, but it has been widely accepted on a wide range of issues, including dietary fat, obesity, smoking, drinking and sex.

This attitude is summed up by the president of the UK Faculty of Public Health, Dr Alan Maryon-Davies, in an article for BBC News Online: ‘We need to press for more legislation to improve and protect health and wellbeing. We need a big stick to curb the worst excesses of the various commercial interests who shape our lifestyle. We’ve been largely successful with the tobacco industry, and now it’s time to shift the focus on to alcohol and junk food. Voluntary codes of practice – in effect self-policing by the food and drink industry – simply haven’t worked. The government has got to stop pussyfooting around and get tough.’ (4)

While the case against active smoking has been well made – most people realise it is probably bad for them – there is little reason that the vast majority of us can’t work out what to drink or eat. If the public health authorities have been ‘successful’, it has been because a distorted picture of the risks of perfectly normal activities has been used to scare us into going along with their policies.

The panic around salt is a good example of this trend. Salt is essential for good health; it is also essential for good food. To treat salt as a little pot of poison on the dinner table causes unnecessary anxiety whenever we eat. It also robs us of the unalloyed pleasure of tasty, well-seasoned food. Doctors should stick to treating the sick, and leave the rest of us to explore the pitfalls and pleasures of life.

Rob Lyons is deputy editor of spiked.

(1) See the CASH website

(2) Systematic review of long term effects of advice to reduce dietary salt in adults, British Medical Journal, 21 September 2002

(3) See, for example, Heat related mortality in warm and cold regions of Europe: observational study, British Medical Journal, 16 September 2000

(4) Why we need more nannying, BBC News, 4 February 2009