Many of us remember being told by our mums to gargle warm water and salt to ease the pain of mouth ulcers.
Conversely, the old saying “rubbing salt into the wound” suggests salt makes things worse and results in more pain.
The use of salt water can be traced back to the Greeks, Romans and Egyptians, all of whom used it to treat cuts, wounds, mouth sores and skin irritations.
Thousands of years later, a concentrated form of salt water, called saline, is often used in medicine: From at-home cleaning of new body piercings to cleansing of incisions during surgeries.
Salt water helps to clean and promote healing by a process called osmosis. The chemical comprising salt – sodium chloride – forces the liquid in cells to move out of the body when it comes in contact with them. If those liquids are bacterial, they’ll be forced out too, effectively helping cleanse the skin.
This process, which is effectively dehydration of damaged cells, is considered antibacterial and, by virtue, anti-inflammatory.
Water from the ocean contains a very high amount of salt in weight, around 35,000 parts per million (ppm). High-concentration saline, similarly, has roughly that same volume of sodium chloride.
SALINE NOT SALT WATER FROM THE SEA
Saline has a specific scientific meaning, however; it’s not just salt water from the sea. The key difference between the two is simply about hygiene: Saline is sterile, sea water is not.
In fact, there are actually some dangers in going in sea water when you have an open wound. While the multiplication of most bacteria stops with contact to salt, there are certain types (such as Staphylococcus aureus) that thrive in salt water.
Moreover, oceans don’t just contain water and salt. They can contain bacteria and other substances of their own, as a product of water from different rivers running together. The nature of these substances can vary, and potentially be harmful to the human body.
While it can be fine (and beneficial) to use sea water, with that in mind, it’s safest to stick to either saline or an at-home solution of table salt and water to help any cuts and wounds heal.
For a mouth ulcer, you can simply use one teaspoon of table salt with a 250ml glass of water. Warm water doesn’t increase the effectiveness of salt per se, instead, it just helps it dissolve faster so it doesn’t sit at the bottom of your glass. According to British Dental Journal, salt water rinses can be useful for all-round mouth health, because they temporarily alkalise the mouth or increase its pH levels, deterring the proliferation of bacteria.
NOT SAFE TO DRINK
Swallowing salt water, however, can be harmful. We all know if we’re stranded on an island not to drink the ocean water. The reason for this is because the osmosis process will force internal water out of your body and dehydrate you.
On the note of islands and beaches, you might have noticed when you go on holiday and spend a week swimming in the sea that skin acne and other superficial lesions can improve. There’s no research behind this, but it’s suggested the osmosis process works like exfoliation: It removes bacteria and dirt and allows an acne lesion to heal cleanly and quickly.
Epsom salts, which are found in the personal care section of the supermarket, do not actually contain salt at all. Named after a saline spring in England, they’re actually magnesium sulphate and are commonly used in baths for natural detoxification purposes. However, there is no published science to confirm the effectiveness of Epsom salts.
If salt is to be used for any medical cleansing reason, sterility is vital and you should use saline purchased from a pharmacy to avoid any risk of wound contamination.
With all that said and done, salt water is almost uniformly seen as a helpful aid in human health. Why, then, does “rubbing salt into a wound” infer it makes something worse?
The idiom’s rationale is twofold. Like alcohol, another cleansing agent, salt will sting an open wound and cause initial pain before improvement follows. Moreover, because of salt’s gritty, rough texture, the rubbing of it would cause a cut or wound to tear – furthering that agony.
For these reasons, we use salt dissolved and diluted water for optimal effectiveness with minimal pain.
Lee Suckling has a master’s degree specialising in personal-health reporting. -stuff.co.nz
