What is salt and sodium?

Salt (sodium chloride) is a compound made of 2 elements — sodium and chlorine. A bit less than half of the weight of salt is sodium and the rest is chlorine.

Salt has been used to flavour and preserve food for centuries. Salt is an important part of your diet and helps your body function.

However, having too much salt in your diet can increase your risk of health complications such as heart disease and stroke. This is often caused by having too much sodium.

Most Australians consume more salt, and therefore sodium, than health guidelines recommend.

Why is sodium important for my body?

Sodium is an element that helps your body function by:

• controlling your blood pressure
• keeping the right balance of fluids in your body
• allowing your nerves and muscles to work properly

Sodium enters your body through what you eat and drink. It leaves your body mainly through sweat and urine (wee).

How can sodium impact my health?

Having too much sodium in your diet increases your risk of high blood pressure, which can cause:

• heart disease
• stroke
• heart attack
• chronic kidney disease

Having a healthy diet will usually provide the right amount of sodium for your body. However, levels of sodium can get out of balance.

The sodium level in your blood can measured with a blood test. Your doctor will get the result in millimoles per litre (mmol/L).

Hyponatraemia

Hyponatraemia is when you don't have enough sodium in your blood. For an adult, hyponatraemia is a sodium level of less than 135mmol/L.

Hyponatraemia is usually caused by too much sodium leaving your body through:

• diarrhoea
• vomiting
• hyperhidrosis (excessive sweating)

Hyponatraemia can also be caused by having too much fluid in your body, through:

• drinking large amounts of water
• water retention
• drinking too much alcohol

Symptoms of hyponatraemia include:

• confusion
• nausea and vomiting
• headache
• muscle twitching and seizures
• balance problems

Severe hyponatraemia can lead to a coma and can even cause death.

Hypernatraemia

Hypernatraemia is when you have too much sodium in your blood. For an adult, this is a sodium level of more than 145mmol/L.

Hypernatraemia is usually caused by dehydration (losing a lot of water that is not replaced). Dehydration can be caused by:

• vomiting
• diarrhoea
• having a fever
• certain medicines

Symptoms of hypernatraemia include:

• thirst
• confusion
• weakness
• tiredness
• seizures

Severe hypernatraemia may lead to coma and can even cause death.

Sodium and exercise

You lose sodium when you sweat. Sweating can be caused by:

• intense exercise for a long time
• exercising or doing physical work in the heat

If you sweat a lot you may need to consume more sodium than what the guidelines suggest. This will help you make up for the sodium you lose.

What foods and medicines are high in salt?

Most salt in the average Australian diet comes from eating processed and packaged foods. A much smaller amount comes from the salt that is added at the table or during cooking.

Some foods that are high in salt include:

• packaged and processed meals
• potato chips and other salty snacks
• processed meats such as ham, bacon and salami
• burgers and pizza
• some sauces and spreads, such as Vegemite and soy sauce

A food does not have to taste salty to be high in sodium. For example, sweet biscuits can be high in sodium because they are made with sodium bicarbonate (baking powder).

Some medicines and dietary supplements contain high levels of sodium. If you use these regularly, check the packet or Consumer Medicines Information leaflet for the sodium content.

Other foods like bread and some breakfast cereals also contain a moderate amount of sodium. These foods should be eaten in moderation to make sure you have a healthy and balanced diet.

Are some types of salt healthier than others?

All salt in food contains some sodium. Having too much sodium in your diet can increase your risk of health complications.

There are many different types of salt, such as:

• table salt
• sea salt
• pink salt
• Himalayan salt
• black salt

Some brands of salt claim to be healthier because they contain additional minerals.

However, additional minerals may only be present in very small amounts. You will usually get enough additional minerals in your diet from other sources.

Iodised salt

Iodised salt is salt that has had iodine added to it.

Iodine is a mineral that is essential for your health. It helps control your:

• growth
• metabolism
• body temperature

Iodine is especially important if you are pregnant or breastfeeding. It can help your baby's brain and nervous system develop.

Iodine deficiency (too little iodine) can impact your neurological function.

Table salt with iodine is widely available. All Australian commercial bread (except organic bread) is made with iodised salt.

Are salt substitutes safe?

Some packaged products labelled as 'reduced salt' contain salt substitutes. Salt substitutes and reduced-sodium salts may not be suitable for everyone.

Salt substitutes usually combine sodium chloride with another mineral called potassium chloride. This reduces the amount of sodium in the food, but can lead to increased levels of potassium in your blood.

You should seek advice from your doctor before using salt substitutes or eating foods with salt substitutes if you:

• have kidney disease
• take non-steroidal anti-inflammatory medicines
• take certain blood pressure medications, including ACE inhibitors and angiotensin II receptor blockers

How much sodium do I need each day?

It's recommended that adults have less than 2,000 milligrams (mg) of sodium each day. This is equal to about 5 grams (g) of salt or 1 teaspoon.

Staying below this amount of salt in your diet may help prevent complications, such as high blood pressure.

For adults, a healthy amount of sodium per day is 460mg to 920mg (1.15g to 2.3g of salt per day).

Recommended sodium intake for Australian children

*Adequate intake is the average level that is estimated to be adequate in healthy children.

Age	Adequate intake for sodium*	Salt equivalent weight
1-3 years	200-400mg/day	0.5-1g/day
4-8 years	300-600mg/day	0.75-1.5g/day
9-13 years	400-800mg/day	1-2g/day
14-18 years	460-920mg/day	1.15-2.3g/day

How can I find out how much sodium is in my food?

Food labels in Australia must list the total sodium content. This includes:

• naturally occurring sodium
• sodium from food additives
• sodium from added salt

All of these sources of sodium count towards your daily sodium intake.

See the nutrition information panel on the food packaging for the:

• total amount of sodium you are consuming in the 'per serve' column
• amount of sodium per 100g — this helps you compare the amount of sodium between foods

Guidelines recommend that you choose foods with less than 400mg of sodium per 100g. Foods labelled 'low salt' have less than 120mg sodium per 100g.

Salt products that contain sodium include:

• rock salt
• sea salt
• celery salt
• garlic salt
• onion salt

Other cooking ingredients that may also be high in sodium include:

• baking powder
• yeast extract
• monosodium glutamate (MSG)
• sodium bicarbonate
• stock cubes

Sodium from any source can increase your risk of health complications if you have too much.

How do I convert sodium to salt?

You can use the amount of sodium in your food to calculate the amount of salt.

To convert sodium to grams (g) of salt:

1. take the amount of sodium in milligrams (mg)
2. multiply this by 2.5
3. divide this number by 1,000

For example, 100mg of sodium × 2.5 = 250mg salt divided by 1,000 = 0.25g salt. So, 100mg sodium equates to 0.25g of salt.

You can also use the Heart Foundation's sodium and salt converter.

How can I reduce my sodium intake?

Most salt in an average Australian diet is from salt contained in processed foods.

To reduce the amount of processed foods in your diet, it's helpful to follow the Australian Dietary Guidelines, which recommend:

• plenty of vegetables
• fruits
• whole grains
• nuts and seeds

To reduce your sodium intake you can:

• check food labels
• choose foods labelled as 'low-salt', 'salt-reduced' or 'no added salt'
• avoid adding salt at the table or while cooking
• instead of salt, use garlic, herbs and spices to flavour your food
• cook your own food as often as possible, instead of eating takeaway food and pre-packaged foods
• limit your intake of salty snacks or processed meats

You can 'retrain' your taste buds to become used to having less salt. If you reduce your salt intake gradually, after a while you might not notice there is less salt.

Speak to your doctor if you want to change your diet. They may suggest you see a dietitian.

A dietitian can help you change your diet while making sure you still get all the nutrients your body needs.

Resources and support

For more information on dietary salt and sodium, speak to your doctor or a dietitian.

To learn more:

• Visit the Heart Foundation for information on how to make healthy lifestyle changes.
• Read more about food labelling on the Food Standards Australia New Zealand website.
• Find information about healthy eating for Aboriginal and/or Torres Strait Islander peoples at eatforhealth.gov.au.
• Visit healthtranslations.vic.gov.au to read about ways to support your child's healthy eating, in languages other than English.

You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to speak with you 24 hours a day, 7 days a week.