A little less than 10 years ago, biochemist and strict vegan Dr James Costello was holidaying on Hainan Island. His routine was to work out before a poolside lunch. He would request dishes with no added salt, as he believed that eating too much of it could lead to high blood pressure and a greater risk of heart disease.
The operator running the restaurant also ran the health club, and one day while taking Costello's order inquired about the no-salt diet. 'We Chinese know that salt is a battery for your kidneys,' the operator admonished. 'Salt is key to life and strength.'
Costello went home and looked into the matter. Sure enough, he found that the body's cells need sodium chloride to balance bodily fluids and help nerve and muscle functions. One of the most common ways to get sodium is through salt.
'But we grew up with table salt, which is highly processed at 650 degrees Celsius and stripped of its minerals. It has an anti-caking agent to stop it from sticking together. Table salt is something unnatural the body can't recognise,' Costello says.
Instead, he turned to saffron-pink Himalayan salt. It was created 300 million years ago, he says, 'before pollution.' As sea water dried out, its salt became embedded into the rock, where it is now found. Crushed crystals contain from 70 to 90 trace minerals and have properties that can balance blood pH (acidity/alkalinity) levels and blood pressure.
Costello saw how it was different to the 'bad' salt and began importing pink salt crystals. These are double ground in Hong Kong and sold by the company he formed with his brother, Stephen James Luxury Organics.
'All the time I was questioning being vegan and vegetarian because I always felt a little weak. After taking in some salt, I really did notice an energy increase,' Costello says.
Is salt suddenly good for us? Mimi Sham, a registered dietitian, agrees it has always been fundamental to health, and that salts like the pink Himalayan option are closer to the natural salts humans consumed for years. 'Historically, that's where we got salt for seasoning to make things taste better,' she says.
Still, consumers may need to evaluate their lifestyles before refilling the salt shaker. Natural salts have been shown to contain more trace minerals than mass-produced salts, including magnesium, a mineral fundamental to good health that is good for bone formation and energy release, Sham says. Levels of sodium in both types remain the same.
According to the British Food Standards Agency, salt is made up of two components - sodium and chloride. It is the sodium in salt that can lead to health problems. There is about 2,400mg of sodium in six grams (about one teaspoon) of salt. The World Health Organisation and the Food and Agriculture Organisation of the United Nations suggest that sodium intake should be less than 2,000 mg (or 5 grams of salt) a day.
The ubiquity of processed food in the modern diet means many people consume an excessive amount of salt. It is used to prolong a product's shelf life, as well as to add flavour.
The Hong Kong diet is particularly prone to high sodium content. Traditional foods like soy sauce, pickled vegetables, salted fish and egg snacks are all culprits. Western processed food and a preference for eating out contribute to the problem.
A local study from 2000 to 2002 by Chinese University found that the average salt intake here was 9.9 grams a day - almost double the WHO's guidelines.
But even the guidelines are generous, says Patricia Chiu, a registered dietitian and nutrition expert with World Cancer Research Fund Hong Kong.
'The amount of sodium we need is actually very small; much lower than the recommended intake,' she says. The study suggested that 75 to 80 per cent of Hongkongers' salt intake came from eating processed food, including shop-bought stocks, sauces and soups, meat and MSG.
'It's the amount of sodium we should be watching,' Chiu says. This means natural salt products are not beneficial unless they are part of a natural diet. Chiu says preparing food from scratch using whole, fresh foods is a key way to lower salt intake. She advises using herbs and spices as seasonings rather than salt. Chives, chilli, curry powder, coriander, basil, garlic, ginger, black pepper, lemon juice and vinegar are just some of the options, she says.
Avoid eating out too often, and when you do, be choosy. Even pre-made salad dressings are full of additives, preservatives and sodium, so try ordering salads dry, with a wedge of lemon.