What is salt?
When we think of salt, we generally think of table salt that we add to our food, conjuring up thoughts of heart disease from all the negative press.
Table salt is made by combining two compounds, hydrochloric acid (HCl) and sodium hydroxide (NaOH), to produce sodium chloride (NaCl) and water (H20). However, the word salt actually applies to a large group of compounds that have many different uses and properties.
A salt is an ionic compound, containing both positive cations and negative anions, held together by electro static forces that are electrically neutral (a cation is commonly a metal, while an anion is a halide).
Salt can be both sweet and bitter and comes in a range of different colours. Some salts are even used for dying clothes while others are burnt in fire-works to produce the amazing displays we see on New Years eve and at other celebrations.
Some salts dissolve in water while others do not; the salts that dissolve in water have a remarkable quality, they can conduct electricity, these are called electrolytes (more about these soon!).
What are the effects of too much salt?
It is true that too much salt increases the volume of water in our blood vessels and this in turn puts pressure on the artery and capillary walls of body tissues, including the brain. Arteries take oxygenated blood from the heart to body tissue. This increase in blood pressure (hypertension) means the heart has to work harder to pump the extra fluid around the body.
There are other factors that can also increase blood pressure. Cardiac output measures the number of heart beats per minute. Depending on activity level, the average is 60 to 100 beats per minute, which ensures a constant supply of oxygen and nutrients to body tissue. Heart arrhythmia can be irregular (fibrillation), fast (tachycardia - above 100bpm) or slow (bradycardia - below 60bpm.) An increased heart rate will increase blood pressure.
Healthy arteries expand with each heartbeat, artery walls can dilate and constrict to either reduce or increase blood pressure. High blood pressure over a long period of time can cause damage and tears to artery walls. Substances like cholesterol, fat and calcium can get trapped in these tears and create a build-up called plaque. The plaque build-up reduces the diameter of the arteries further. Blood cells can stick to the plaque and harden causing what is known as clots. These clots can also break off causing blockages, preventing blood flow and subsequently oxygen to tissue. A lack of oxygen to the brain can cause a stroke, restricted flow to the heart can cause angina (chest pain), while a complete blockage causes a heart attack.
High levels of fats and proteins in the blood increase the viscosity (thickness) of the blood, so too can chronic stress, all these factors can increase blood pressure, and all these factors cause heart disease, heart attacks and strokes. It appears that some people are more susceptible to the water retention effects of sodium than others.
What can I do to reduce my risks?
Try to eat a healthy diet full of vegetables, fruit, and whole grains, reduce your alcohol consumption, take regular exercise, if you are over-weight try to reduce your weight and, if you smoke, quit!
The charity ‘Blood Pressure UK’ runs a campaign called ‘Know your Numbers’ that encourages adults across the UK to know their blood pressure numbers and take the necessary action to reach and maintain a healthy blood pressure. When the heart muscle contracts it is called systolic pressure and when it relaxes this is called diastolic, the ideal blood pressure for an adult is 120/80.
Not all salts are bad. Electrolytes are salts, some have a negative charge, while others are positive. Electrolytes include sodium, potassium, calcium, bicarbonate, magnesium, chloride and phosphate.
Sodium along with other salts are needed to generate electricity within the body, which is essential for many bodily processes. Sodium is needed for the transportation of oxygen, muscle contraction and amino acid transportation.
Potassium is also required for muscle contraction, nerve impulses, to preserve your acid-base balance, glucose and glycogen metabolism, to transmit electrical signals between cells and nerves and for regulating fluid balance.
The negatively charged sodium and chloride ions work outside the cell (extracellular) along with positively charged potassium ions that work inside the cell (intracellular), both are necessary to create nerve impulses.
Electrolytes conduct electricity when in water. They are especially important in cells, tissues, nerve impulses and muscle contractions. Muscles rely on a perfect balance of sodium, potassium and calcium to contract, an imbalance can cause either excessive contraction (cramp) or weakness. It is worth noting that the heart is a muscle. Electrolytes also hydrate the body, help with tissue repair, balance acidity and control pressure. The kidneys and certain hormones regulate electrolyte balance. When electrolyte concentrations are too high the kidneys work with these hormones to filter them from the body. From this, it is easy to see why salts are so essential to our health.
An imbalance of electrolytes can cause many symptoms depending on which electrolyte is out of balance. An imbalance of magnesium, sodium, potassium or calcium can cause irregular heartbeat, bone disorders, muscle twitching, changes in blood pressure, confusion, numbness and tiredness. Signs of excessive calcium are frequent urination, muscle spasms, irregular heartbeat, nausea and coma to name a few.
A well-balanced diet high in wholegrains, fruit and vegetables will help to keep your electrolytes balanced. Nutrients work synergistically in our body, they are found in fresh, unrefined food in the correct balance that our body needs, and not in refined, processed foods.
Minerals are essential to good health and need to be obtained through our diet as, unlike vitamins, we cannot manufacture our own. We need specific amounts of minerals and this can change from person to person depending upon individual lifestyle (exercise, diet, medication, health status and where the food we eat is grown). The fluids in our body have a natural balance of minerals. Drinking too much water that is low or void of minerals causes our body to become depleted of those important minerals. When we drink water that doesn’t have minerals, the minerals in our body are absorbed into that new water and our natural balance is therefore diluted. So, drinking water low in minerals causes our body to leach important minerals into the water we’ve just drunk to maintain the whole body balance. Distilled water and even mineral waters are low in minerals. A good way to enhance drinking water to prevent upsetting the balance of minerals in our body is to add a little salt. Table salt (NaCl) is made of only two minerals, sodium and chloride, so it’s not going to help prevent mineral leaching from the body. Instead, Himalayan pink salt, which is higher and more diverse in minerals, is a good option, adding a pinch to 4 litres of water is enough.
What are the effects of low salt levels?
When sweating a lot due to work, exercise or illness (vomiting or diarrhoea) we lose a lot of essential minerals, especially electrolytes. Low salt in the body (hyponatremia) can cause symptoms such as headaches, nausea, confusion, muscle weakness and cramps and seizures.
When exercising for under an hour water alone is fine. However, when exercising for longer than an hour you should add electrolytes to your water and sip every 15 minutes. You should also bear in mind that:
Some people sweat more than others, be aware that you may need to drink more
You will sweat more when temperatures are higher.
Tea coffee and alcohol can act as diuretics further dehydrating you.
Remember fruits and vegetables are naturally high in water, so a good way to keep us hydrated. They also have a good balance of minerals in a ratio that our body likes.
Although it’s important to have enough salt, keep in mind that the recommended daily amount of salt is no more than 6g (2.4g of sodium) per day, which is about 1 teaspoon.