The sodium in common salt is essential to life, but too much can be harmful in more ways than one.
Doctors routinely warn patients with high blood pressure to cut back on salt as a high level in the bloodstream can increase diastolic pressure, directly influencing the brain's "thirst center."
Herbalist Kieu Ba Long recommends consuming no more than five grams of salt daily for people with high blood pressure, which is equivalent to one quarter of a coffee spoon, and warns against eating extra sugar to compensate for the reduced salt intake.
Best is to eat unrefined sea salt because it also contains calcium, magnesium, potassium, sulphur and iodine.
Not too much, not too little
Just because too much salt is bad for us doesn't mean we have no need of it. Indeed, salt is vital to health, and determining the optimum amount has been the subject of much medical research.
In the USA, research found that the body maintains a balance by excreting less salt when a person is fasting. One scientist went so far as to stop his salt intake for an extended period of time and found that his body adapted to the change and continued to function normally.
At the University of California in San Francisco, Dr Kirsten Bibbins-Domingo found that teenagers who restricted their salt intake were less prone to high blood pressure in later years.
Meat already contains plenty of sodium chloride, much more than vegetables in fact, yet people routinely add salt to their cooking and sprinkle it liberally on their meals, partly because salt brings out the flavors more. The end result is too much sodium in the system.
According to Dr Dao Thi Yen Thuy, a baby under six months of age needs 1,200mg of salt per day, while a child of ten needs 5,000mg.
The National Institute of Nutrition says that a strong and healthy person needs 6-10g salt every day.
However, people who lose a lot of salt through perspiration, for example outdoor laborers and athletes, should supplement their salt intake with soup, fried food, salted fish, pickles, soy sauce and such.
Like her colleagues, Dr Thuy stresses the point that people with high blood pressure, other cardiovascular disease, diabetes or kidney disease should go easy on the salt.
She also recommends that infants under six months old, especially the prematurely born, be breast-fed only as infant formula contains too much salt.
After six months of age, infants' food can be lightly seasoned with salt or fish sauce, but only a little as their taste buds are more sensitive than adults'. What tastes right to a grown-up may be too salty for a tiny tot.
Furthermore, children should be encouraged to drink plenty of water to expel more salt through their urine.
Salt for ailments
In traditional medicine, salt is used to enhance herbal remedies and to kill pathogens around an open wound, says herbalist Le Ngoc Van, chairman of the Traditional Medicine Association of Phan Rang-Thap Cham, Ninh Thuan Province.
Van says salt is commonly used in folk treatments home remedies, and offers the following advice:
- As an emetic for food poisoning, dissolve one spoon of salt in 100ml of water and swallow two mouthfuls. Then press the back of the tongue with one finger to induce vomiting. If the symptoms of food poisoning persist, see a doctor.
- To fix a sore throat, dissolve two spoons of salt in 100ml of warm water and gargle a dozen times daily.
- To treat scalding from boiling water, mix a little salt with sesame oil and rub into the affected part of the body to make it cool and soft, decrease swelling, and dry out the skin. Do this twice daily for one week.
- To treat a livid bruise on a child, mix one spoon of salt with eucalyptus oil and apply to the bruised area twice a day.
- To beat tinnitus, heat some salt in a cloth bag, then press the salty bag against the ears for 10 minutes once weekly.
- To defeat body odor, roast some unrefined salt until it is very hot, put it in a cloth bag, and rub under the armpits until the bag is cool. Do this twice daily for two weeks.
- To ease rheumatic pain, rub salt on the joints before going to bed.
Van's colleague Hoai Vu has some advice vis-a-vis salt too:
- When working in the hot sun or a high-temperature environment, add some salt to drinking water to recover the lost sodium.
- To stop bleeding of the gums or exposed root stump, brush the teeth with ground salt instead of toothpaste.
- To treat bloody diarrhea, eat porridge with a liberal sprinkling of salt powder.
- To beat constipation, drink one bowl of weak salty water every morning before breakfast.
- To disinfect a weeping wound, dissolve 6g salt and 15g white alum in warm water, and use the solution to clean the wound twice daily.
- For a bee, scorpion or insect sting, rinse it with salty water several times daily.
- To keep skin soft and smooth in cold weather, add salt to the bath water or facial rinse.
In addition, Dao Thi Hang Nga from the University of Odontology and Stomatology in Hanoi advises that daily gargling with warm salt water keeps the mouth and throat free of harmful germs and improves circulation of the blood around these areas. Just be sure not to use too much salt as it can cause ulcers if too concentrated.
- Add a little salt when whipping eggs to produce a buoyant foam.
- Rub salt into the abdominal cavity before cooking a whole chicken.
- To clean an electric iron, scrape the bottom with paper sprinkled with salt.
- Sprinkle salt on a red wine stain then pour on hot water.
- Wash vegetable with salty water.