First of all: I am not a pediatrician and there is no formal study on the matter (at least I have not found anything).
But I think I have collected enough information from sources of authority to give you a clarifying answer.
2. WHAT’S THE PROBLEM WITH INGESTING THE SALT IN THE NASAL WASHINGS (IN BABIES)
- We know babies should not take (added) salt because their kidneys are too immature to manage salt overloads (words from the Spanish Association of Pediatrics).
- For nasal washes it is recommended to use saline solutions or sea water (both are water + salt). About 2ml/nostril before they’re 2 years old and 5ml/nostril after 2 y 3.
- Children end up swallowing part of that salt with each wash; quantity that, even small (sometimes large), worsens with the number of times we rinse their nose (the SAP recommendation is to do as many nasal washes as necessary).
3. HOW MUCH SALT CAN BABIES SWALLOW DURING NASAL CLEANSING?
Bearing in mind that saline solutions has a standard concentration of 0.9% (9 grams of salt for every liter of water):
- In each 2 ml dose there are 0.018 grams of salt (0.036 grams of salt adding the dose in both holes).
- In each 5 ml dose there is 0.045 grams of salt (0.09 grams of salt adding the dose in both holes).
Assuming that babies swallowed 100% of the saline solution (which is not the case), we would have to do 28 complete cleanings for them to ingest 1 gram of salt in children under 2 years of age and 11 cleanings in older ones.
4. WHAT IS THE RECOMMENDED DAILY SALT INTAKE FOR A BABY/KID?
- <1 year: less than 1 gram of salt per day.
- 1-3 years: less than 2 grams of salt per day.
- 4-6 years: less than 3 grams of salt per day.
- >6 years: less than 5 grams per day.
This is an estimate based on the recommendations of the World Health Organization and the British National Health Service.
5. SHOULD WE WORRY ABOUT THE SALT THAT BABIES SWALLOW IN THE NASAL WASHES?
Data in hand, we should not worry about the salt that babies swallow in nasal washes (if we follow the recommended doses); Well, even in the exaggerated case that they ingested all the saline solution in each cleaning (which I repeat, is NOT the case), we would have to do 20-30 washes a day to reach the recommended maximum.
- Asociación Española de Pediatría (2021). Lavados nasales. Text in Spanish. Available [HERE].
- Asociación Española de Pediatría (2018). Recomendaciones de la Asociación Española de Pediatría sobre la alimentación complementaria > Recomendaciones sobre el consumo de sal y azúcares. Page 11. Text in Spanish. Available [HERE].
- Doctora Di pediatra (2021). Cómo hacer un lavado nasal a un bebé (demostración práctica). Minute 2:45. Available [HERE].
- World Health Organization (2020). Salt reduction. Available [HERE].
- Servicio Nacional de Salud británico (2023). Salt: the facts. Available [HERE].