Is there any such thing as a “salt tooth”? We are familiar with a sweet tooth, and sugar cravings, along with the negative effects of those. We are broadly aware of the downsides of too much salt, including high blood pressure, which puts pressure on the blood vessels, the heart and the kidneys. It can also lead to water retention.
The British Heart Foundation concluded last year that if everyone brought their consumption down to the World Health Organization salt limit of 5g a day by 2030, the result would be up to 1.4m fewer new cases of high blood pressure, 135,000 fewer new cases of coronary heart disease, up to 49,000 fewer new cases of stroke and more than 450,000 extra years in good health.
But salt is not considered a dietary luxury, even though 40% of people, according to a YouGov poll, would put crisps way above chocolate in the treat hierarchy. We don’t tend to police how much we eat – at least, not as rigorously as with sugar – or question whether we are innocently listening to our bodies, which need some salt for basic muscle function, or are in the grip of a compulsion.
A salt tooth is quite unlike a sweet tooth in that it doesn’t create an appetite for itself at the hormone level. Sugar has a well-documented impact on blood glucose, which, unhelpfully, makes you want more sugar. If salt drives an appetite for anything, it’s lager. But salt does make your palate acclimatise, so that the more you eat, the more you need to get the same salty hit. This is why chefs can get heavy-handed with it.
It is so incredibly useful in food manufacturing – for palatability, in preservation – that it is unsurprising, particularly where the ingredients are cheap and need to be camouflaged, to find high levels of salt in most processed foods. This creates a feedback loop between manufacturers and chains, as Henry Dimbleby, the food campaigner and co-founder of Leon, describes: “I think two things may be at play. First, it is clear that we can develop palates that become sensitised to salt, so you can see why there might be a tendency to add more. I have had people complain to me that they took salt out of their pizza and customers switched to a saltier competitor. If you have significant chunks of vegetables or meat in a dish, the perceived saltiness can also go down over time as the salt moves out of the sauce and into the meat or veg, where it has less impact on the tongue.”
The WHO estimates that 80% of the salt we consume has been added during a manufacturing process. Indeed, that is probably the easiest way to reduce intake – to stop eating things you didn’t make yourself.
As Sam Bloom, a nutritional therapist, explains: “With salt what is generally more concerning is the fat that is used in conjunction with it, eg salty crisps, fries and fast food. Ready meals are often the worst for hidden salts. Anything that adds flavour that isn’t a spice or herb will probably have salt added to it and is likely to cause cravings… as its flavouring makes you want to eat more. The salt and fat combination in these foods are what cause problems with cholesterol.” She adds: “The salt that people add to a meal made from scratch is much less concerning.”
But the connection between obesity and salt intake runs deeper than KFC. According to Dr Stuart Grice, a geneticist and the chief scientific officer at FitnessGenes, our desire for salt can be genetically driven and “the same genes that lead to a higher intake of salty food, and salt sensitivity, have been linked with obesity”. Particular genetic variants affect the way different people perceive the taste of salt, Grice continues, which intuitively makes sense of the connection between salt craving and obesity; if you find salt more delicious, you probably find food more delicious. Then there is a second-tier link, whereby “salt is often found in processed and high-fat foods, which are craved by individuals with genetic makeups that increase their risk of weight gain,” Grice says.
Nutritionists’ language of substitution – when you want a Snickers, try a banana – has always struck me as demonstrating a poor understanding of cravings. If the desire were fungible, it wouldn’t be a craving; you would just be hungry. Yet Grice’s careful description of what you could have instead of a pub salad (crisps mixed with peanuts) is convincing: “When a salt craving hits, avoid going straight for salty snack foods such as crisps and instead ensure you are well hydrated. Seek out whole foods, such as olives and leafy greens, which are rich in polyphenols, magnesium and calcium. These foods will help you alleviate salt cravings, which may often be due to a desire for nutrient-rich food.”
Your body can tell you things, sure, but it doesn’t have a large vocabulary. You may think it is shouting “salt”, but it’s actually shouting “minerals”.
Last week, I had crisps for five consecutive meals. Just in case you want to know whose side I am on.
World Opinions + The Guardian.com