In recognition of Salt Awareness Week (11-17 March), we look at how much sodium is in baby formula or breast milk – and how much salt babies can safely consume.
Your kidneys filter the liquid in your body, sending excess into the bladder to be egested as urine, and resorbing useful nutrients. Eating salt increases the levels of sodium in your body, though, and that strains the kidneys and can lead to a higher risk of high blood pressure and strokes. According to the South African government health advisory: “There is also increasing evidence supporting links between our current high-salt diets and the onset of stomach cancer, osteoporosis, obesity and kidney stones and kidney disease.”
That’s why the World Health Organisation (WHO) and individual countries’ government bodies advise people to limit their salt intakes to safe levels.
If you did chemistry in high school, you might remember that table salt or sea salt is made up of sodium (Na) and chloride (Cl). When the ions of the two elements bond, salt or NaCl is made. Salt is made up of about 40% sodium and 60% chloride. One teaspoon of salt contains 2 300mg of sodium.
“In terms of salt content formulas are very similar, varying between each other and from breast milk by just a few milligrams per daily intake.”
So how much salt is safe? The UK’s National Health Service (NHS) says the maximum recommended amount of salt for babies and children up to the age of 12 months is less than 1g (that’s one gram, or a thousand milligrams or 1 000mg) of salt a day or less than 0.4g sodium. For children between one and three years old, 2g of salt a day (0.8g sodium) is acceptable.
For babies younger than four to six months who have not yet started eating solid foods, their salt or sodium sources are solely breast milk or formula milk. Breast milk contains 42 milligrams (mg) of sodium per 250ml, or 21mg per 125ml. Formulas come very close to that, with two leading brands listing 16mg (S26 and S26 Gold) and 19.5mg (Novalac and Novalac Premium) per 100ml. If you do the maths, you’ll see that a baby drinking a litre (likely) or even two litres (extremely unlikely) of milk a day will still ingest far less (160-320mg) than the maximum recommended daily intake of salt.
Alison Campbell Lang is a specialist paediatric dietitian who works in the liver transplant unit of the Donald Gordon Hospital in Johannesburg. She stresses that Codex regulations very specifically regulate how much salt infant formula companies are allowed to use in their products. (The Codex Alimentarius, or “Food Code” is a collection of standards, guidelines and codes of practice adopted by the Codex Alimentarius Commission in the WHO.)
“So, you will never find that one brand contains too much salt, and you really cannot compare one brand with another. They are all safe in terms of sodium,” she says. “Obviously, breast milk is best, but in terms of salt content formulas are very similar, varying between each other and from breast milk by just a few milligrams per daily intake.”
When should you watch out?
“In babies and infants, the reason we are quite strict in advising parents not to salt babies’ food is about setting up taste preferences in the future and encouraging good eating habits and discouraging bad eating habits for life,” says Alison.
“Having said this, I had better add that of course, in extreme doses, an overdose of salt is deadly to infants,” she cautions. Alison recalls seeing a baby, who was fed high-salt two-minute noodles as sole source of nutrition and became extremely unwell ending up in ICU. So, let’s not underestimate the danger of extreme doses of salt.
“As a country with a high incidence of diabetes and hypertension, all of us, children and adults, absolutely need to make lasting, long-term dietary changes,” says Alison.
Alison says: “If a baby starts its life being fed high-salt foods, its parents set up a need for highly seasoned foods. Some parents consider feeding such processed foods a parental indulgence that gives them a feeling of spoiling their baby and enjoying their affluence. Meanwhile, feeding real whole foods like simple cooked oats or a real banana rather than a banana purée from a jar guarantees there are no additives, is cheaper and tastes more natural too.”
“Parents can be duped into believing that a cereal with ‘added spinach’ is a premium, healthy baby food. Real cooked spinach is definitely better than the dehydrated spinach that makes up 2% of the cereal box’s ingredients and is listed right at the end of the ingredients list!”
As a ‘takeaway’ (haha) message, Alison has this general advice: “Processed foods are always higher in salt and whole cooked health foods should be fed to babies whenever possible.” So, resist the cheap marketing tactics, always read the ingredient labels on packaged foods and cook from scratch whenever you can. Your health and your budget will thank you.
The iodine debate
If you’re buying table salt, think about buying idodated or iodised salt. It will be marked as such on the label. The World Health Organisation (WHO) has recommended that iodine be added to table salt to help people take in enough of it – iodine helps prevent hyperthyroidism and is critical to an infant’s brain development. Seaweed, kelp, fish and dairy, lima beans and prunes are natural sources of iodine, but your diet may not include enough of these ingredients.
“Most people need an additional source of iodine as it is found in relatively small amounts in the diet. Iodisation is the process of fortifying salt for human consumption with iodine and is an effective strategy to increase iodine intake at the population level,” according to the WHO.