By Dr. Harold Gunatillake - FRCS, FACS, FIACS, AM (Sing), MBBS (Cey)
Salt is a mineral obtained from sea salt or rock salt composed mainly of sodium chloride. It is essential for life and is harmful for animals and plants in excess. We brought our own salt content from the sea during the evolution process in our bodies, in the ‘amphibious stage’, during the process of migrating to land. Salt was one of the oldest food seasoners and also used to preserve food (salting), through those long voyages in the sea.
For human consumption it comes in different forms: unrefined salt (sea salt) which was stored as crystals in coconut shells during our grandmothers’ era, refined salt (table salt), and iodized salt. Asians eating rice and curry regularly tend to consume more salt than those eating Western cuisines where salt is frequently placed on the dining table in salt shakers and very little if not none is used during the cooking process.
In 1994 the British government recommended that people reduce their consumption of salt from 9 grams per day to a maximum of 6 grams per day. This recommendation was after doctors found that excessive consumption of salt could be associated with serious health problems and that the government guidelines should be taken very seriously.
High Blood Pressure
According to most reports appearing in medical journals, it is reported that people who consume high amounts of salt are at risk of stroke and cardiovascular disease. Those who eat less salt per day can experience systolic blood pressure of over 10mm Hg and diastolic blood pressure of 5 mm Hg for people over the age of 55 years, males or females.
A large scale study from 2007 has shown that people with high blood pressure who significantly reduced the amount of salt in their diet decreased their chances of developing high blood pressure and cardiovascular disease by 25% over the following 10 to 15 years. Their risk of dying from cardiovascular disease decreased by 20%.
Salt regulates the water content in our body (fluid balance). Too much of salt in the body increases water content and becomes a strain on the heart resulting in high blood pressure. Hence, health authorities have recommended limitations of dietary sodium.
Persons who have heart failure should restrict salt intake much more than for other diseases. Excess salt consumption by these patients is dangerous. Salt promotes water retention and people who have weak hearts can be very sensitive to water retention and develop decompensated heart failure if they ingest significant amounts of salt. These patients have shortness of breath (fluid in the lungs), chest pain, sweating, leg swelling, and they feel they are drowning. These patients should go on a salt free diet and diuretics to rid the excess water in the body. The results are dramatic.
Excessive salt intake leads to excessive calcium loss from food and thereby becomes a risk factor in osteoporosis especially for women during the menopausal stage.
There is further evidence that when we excrete too much calcium, our intestinal absorption of calcium increases and our bodies compensate by using calcium from our bones. Thus, lowering your salt intake will also reduce the excretion in the stools, leading to a positive calcium balance, and bone density.
Researchers from Leuven University in Holland reviewing the dietary habits of individuals from 24 different countries have noted that a high intake of salt significantly increases the risk of stomach cancer. This may account for the high incident of stomach cancer in Japan where salt consumption is higher.
Bronchial (tubes leading to the lung tissue) inner lining sensitivity is related to sodium (salt) balance. Severity of asthma is related to salt intake. Reduction in salt intake may reduce the frequency and severity of asthma. So high salt intake is not a direct cause, but may only be an aggravating factor.
Eating foods with high salt intake like dry fish, lime pickle and other Asian appetizers on a regular basis increases the salt retention in the body tremendously. Thirst created on eating such salty foods is relieved with high-sugar or high calorie beverages, which leads to obesity. Increased salt intake has been recognised as an important factor in obesity. Reduction in salt intake may lead to a reduction in obesity.
This is a condition which manifests with the following symptoms including vertigo, tinnitus (ringing noise in the ears), fluctuating hearing loss and a feeling of pressure in the ears. This affects people as they grow older. The cause is not known, but restricting salt intake helps. People who suffer from vertigo alone should restrict salt intake. Also reduce the intake of salt containing processed foods, canned foods, smoked meat and prepared meals also helps.
Elderly people need more salt than the young, since they are more sensitive to the electrolyte balance in their bodies. The elderly suffers from high blood pressure too, but by restricting or reducing salt intake can cause a condition called, ‘hyponatremia’ (reduced salt in blood). In this regard low blood sodium has been fatal to marathoners and football players who disregard proper hydration. The elderly become weak, muscle cramps, dizzy and confused when the sodium (salt) level is reduced far too low and cause electrolyte disturbance, which can cause neurological problems or death.
Drinking too much of water with insufficient salt intake, puts a person at risk of water intoxication.
Most of our salt comes from food, some from water. It is recommended that water and salt lost in exercise and when working outside should be replaced. Professional chefs need to drink plenty of water and added salt due to the hot environment they work in. Wilderness hikers know the importance of salt tablets to combat hyperthermia. Expectant mothers are advised to get enough salt. Increased salt intake is required to combat chronic fatigue syndrome. Salt is strongly recommended for the Himalayan climbers.
Substitute for salt
Use herbs, spices, thyme, stir fry with garlic or other natural flavorings to spice up, or condiments like relish, mustard and ketchup (ketchup can be loaded with salt) for cooking without adding salt.
Eat small meals more frequently during the day like the Chinese, you eat less salt than eating large meals which increases workload on the heart as increased circulation is required to metabolise and digest all the food with the excess salt.
New Thoughts — Controversy
Some authorities feel that there is no evidence that reducing dietary sodium improves the risk of heart disease or strokes for the general public and not in individual situations.
In 1999, the Canadian Hypertension Society, the Canadian Coalition for High Blood Pressure Prevention and Control, the Health Canada Laboratory Centre for Disease Control and the Heart and Stroke Foundation of Canada issued a joint statement opposing general recommendations for sodium reduction.
The U.S. Preventive Services Task Force has also reviewed the evidence and concluded:
“There is insufficient evidence that, for the general population, reducing dietary sodium intake or increasing dietary intake of iron, beta-carotene, or other antioxidants results in improved health outcomes.”
This different thought on intake of excess salt confuses the public. The authorities that state that salt has no link to disease are those having commercial vested interests. Meanwhile, the general public should restrict taking not more than 6 grams a day.
The National Academy of Sciences recommends that Americans consume a minimum of 500 mg/day of sodium to maintain good health, and not more.
Fast food contains more salt than home cooked food. So, it is recommended to eat such food less frequently as possible, especially among young people.