It takes just half an hour for one salty meal to significantly impair the arteries’ ability to pump blood around the body, alarming research shows.
Blood flow becomes temporarily more restricted for between 30 minutes and an hour after the food has been consumed.
Scientists tested how quickly salt had a damaging effect on the body by recruiting 16 healthy adults and feeding them each a high-salt meal, containing 4g, and later a low-salt meal, made with just 0.3g.
Before and after each meal, they tested how smoothly blood was flowing in the brachial artery – the main blood vessel in the upper arm which is normally used for checking blood pressure.
Although the artery does not measure blood flow directly to the heart, it is commonly used to give an indication of cardiovascular health.
The results, published in the American Journal of Clinical Nutrition, showed blood flow was significantly more impaired within 30 minutes of eating the salty meal than the low-salt alternative and the restriction reached a peak after an hour.
In a report on the findings, the authors from a group of research organisations in Adelaide, Australia, said: ‘This study showed the amount of salt similar to that in a commonly eaten meal impairs blood flow in healthy men and women.
‘The mechanisms for this need to be investigated more intensively.’
British experts last night warned that many families typically eat a high salt meal containing 4g or more most nights.
Professor Graham MacGregor, chairman of the lobby group Consensus Action on Salt and Health, said: ‘This research is of great interest.
‘It clearly shows a rapid effect on the stiffness of the blood vessels.
‘It looked at the effects of eating just four grams of salt.
‘That’s not particularly high and is probably average for many meals consumed.
‘In fact, if you eat out you will probably consume more than that. This kind of damage to the blood flow is thought to be a very early sign of heart disease.
‘Every time you eat a salty meal you are altering the function of the cells that line your arteries.’
Salty diets have been linked to an increased risk of heart attacks, strokes, kidney disease, osteoporosis and stomach cancer.
It's The Kind of Salt That Makes The Difference
Not all salts are created equal. An increased intake of 'good' potassium salts could contribute significantly to improving blood pressure at the population level. The problem is that most salt incorporated into foods are processed and nutrient deficient.
The favourable effect brought about by potassium is even estimated to be comparable with the blood pressure reduction achievable by halving the intake of 'bad' sodium salts (mostly from table salt).
In its purest form, unrefined natural salt is necessary for many bodily functions. It helps create critical body fluids, such as blood plasma and lymphatic fluid, carry nutrients to cells, regulate blood pressure and nerve impulses and is a factor in allowing your brain to communicate with your muscles so you can move.
Experts argue that salt could be just what we need for healing, health and longevity. Modern salt, they agree, is unhealthy. But common table salt has almost nothing in common with traditional salt, say the salt connoisseurs. Just look at the rose-coloured crystals of Himalayan rock salt, or the grey texture of Celtic salt – both pride themselves on traditional harvesting, avoiding heat treatment or refining methods – and you know you're getting something special, not least that when you taste them, they actually have flavour. And unlike the sodium chloride you find on most kitchen tables, unrefined rock salt contains more than 84 different minerals.
"These mineral salts are identical to the elements of which our bodies have been built and were originally found in the primal ocean from where life originated," argues Dr Barbara Hendel, researcher and co-author of Water & Salt, The Essence of Life. "We have salty tears and salty perspiration. The chemical and mineral composition of our blood and body fluids are similar to sea water. From the beginning of life, as unborn babies, we are encased in a sack of salty fluid."
Celtic Sea Salt
Celtic Salt is a great salt harvested from the current ocean. Its harvested by hand and left unprocessed so it contains the important trace minerals absent in chemically treated table salt.
Himalayan brands are harvested from an ancient salt deposit that would have been created long before there were any modern toxins. Geologically, the Himalayan deposits have the full spectrum of minerals and considered crystal salts.
Processed Foods Are The Biggest Culprits
Bread, processed foods and ready-made sauces are some of the items that contain the highest chemcially treated salt levels, although supermarkets have gradually been reducing quantities in oven-ready meals.
Health experts estimate that cutting average consumption by just a couple of grams a day would slash strokes by 22 per cent and heart attacks by 16 per cent.
Research published last year suggested heart disease could be cut by almost a fifth if food companies were banned from adding too much conventional salt to their products.
Laws to restrict the salt content in ready meals, pizzas and sandwiches would be 20 times more effective in improving health than offering dietary advice, experts said.