Sodium is a mineral that is essential for life. It is needed for our muscles and nerves to function, and it maintains the balance of water inside and outside of our body’s cells. Sodium is also essential in maintaining the volume of our blood serum (the part of blood that’s not red and white blood cells, clotting factors, etc) and supports the transport of different molecules into our cells. Our bodies maintain a delicate balance of electrolytes like sodium, potassium, and calcium to keep these important functions operating as they should.
Sodium in the diet
Most of the sodium we consume is in the form of sodium chloride, which is regular table salt. Sodium also comes in many other forms such as sodium bicarbonate (in baking soda), sodium phosphate (in cheese), and can also be found in toothpaste and medications like aspirin.
Sodium naturally occurs in almost all foods we eat including fruits, vegetables, and meat. If we only received our sodium from these foods we’d have plenty enough for our body’s functions. Of course, this isn’t the case for most of us!
75% of the sodium we consume comes from manufactured foods.
Salt is a key preservative, a food additive, and a contributor to flavour in everything from breads and processed breakfast cereals to condiments and snacks. Many sweet foods contain sodium, even though you wouldn’t detect a salty flavour. Salt is omnipresent in the modern food supply and has lead to high sodium intakes in Australia. Health experts recommend we aim for about 1.6g of sodium per day (that’s about 4g salt – salt is 40% sodium and 60% chloride) and less than 2.3g per day (~1 teaspoon). The average Aussie is consuming more than double this amount.
Why is too much sodium a problem?
Around 95% of the sodium we eat is absorbed and moves into our bloodstream. Excess sodium is removed from the blood by our kidneys and is excreted in urine. We also lose a bit of sodium when we sweat.
When we’ve got too much or not enough of a particular nutrient, our physiological equilibrium is out of balance and the body works to get things back into it’s comfort zone (aka homeostasis). The body is extremely efficient at maintaining homeostasis in the here and now, but it’s coping mechanisms can contribute to chronic health issues down the track.
When we habitually consume a diet that’s high in sodium we retain more water. You’d notice this effect with thirst – eat lots of salty food and you’ll feel thirstier. It’s the same inside your body; if you’re absorbing more sodium your body will also absorb more water. This increases our blood volume, which makes our heart work harder and raises our blood pressure. High blood pressure puts more stress on our arteries and the vessels in our brains. Our kidneys filter our blood, so they’ll be working harder to get rid of the excess sodium and fluid.
In short, a consistently high intake of sodium can increase your risk of high blood pressure, which is a risk factor for heart disease, stroke, and kidney disease.
What foods are highest is sodium?
If a food is processed (i.e. it has been changed from its natural form), there’s a good chance it has sodium-containing additives. Here are some of the biggest contributors to sodium in our diet:
- Deli meats (e.g. salami, ham, jerky)
- Smoked, processed, or cured fish (anchovies, canned fish)
- Tomato juices and tomato sauce
- Meat and vegetable stocks
- Seasonings (taco seasoning, meat rubs)
- Packet mixes (gravy, casseroles, meal bases)
- Sauces (soy sauce, BBQ sauce, salsa, Worcestershire sauce, pasta sauce)
- Condiments (relishes, salad dressings)
- Fermented or pickled foods (sauerkraut, kimchi, olives, pickles)
- Salty snacks (chips, salted nuts, crackers)
- Canned soup
- Canned vegetables and legumes
- Cheeses (processed cheese, feta, halloumi)
- Bread and baked foods (muffins, cakes, wraps)
- Instant noodles
- Readymade, frozen, and convenience meals
- Foods eaten away from home (takeaways)
How to reduce your sodium intake
Because of the mounting scientific evidence linking sodium intake and high blood pressure, food manufacturers are feeling the pressure to offer more reduced salt options. That’s fantastic to see, and with many foods you probably won’t notice a flavour difference.
However because salt is so common in foods, our palates have adapted to a high-salt diet. Sometimes when we choose low salt options we might perceive them as ‘bland’. Keep in mind that our tastebuds and food perceptions are flexible and ever-changing so if you’re trying to reduce your salt intake, stick with it! In a matter of weeks you’ll adjust to a lower salt diet and you might even start to notice other flavours in your favourite foods.
A few other tips to reduce your intake:
- Taking a gradual approach can help your palate adjust.
- Taste your food before adding salt at the table.
- Experiment with other punchy flavours – explore herbs and spices.
- Read the nutrition label – look for foods with 120mg sodium or less per 100g.
What about Himalayan salt?
Himalayan salt has been touted as a healthier option than regular salt, but it’s barely different at all in it’s chemical makeup. It’s pink because it contains iron oxide (rust), and it has trace amounts (which means they’re super, super small) of some other elements. In addition, Himalayan salt isn’t fortified with iodine like many regular table salts, which is a big problem considering the high rates of iodine deficiency in many countries including Australia. Choose pink salt if you like how it tastes or looks, but don’t bother if your main motivation is health.
- Australian National Nutrition and Physical Activity Survey, 2011-13 – Australian Bureau of Statistics
- Eating less salt – Dietitians Association of Australia
- How much sodium do Australians eat? FSANZ
- Iodine – Examine.com
- Iodine deficiency and nutrition – Thyroid Foundation
- Nutrient Reference Values, Sodium – NHMRC
- Salt and hypertension – Nutrition Australia
- Salt – the facts – Health Direct
- Types of salt – Authority Nutrition
- Chips image: Emmy Smith
- Spices image: Akhil Chandran