Recently, a carpet burn removed the epidermis, the top layer of my skin, of my upper middle finger. It left a large open wound on my hand. Fortunately, I was close to the ocean so I could swim in the seawater to speed up the healing process, or so I thought.
Tissue regeneration consists of 4 major phases. These include the hemostatic phase where there is activation of the coagulation cascade; the inflammatory process where blood flow to the affected area is increased; the proliferation phase where new skin cells are born; and the remodeling phase where there is a replacement of collagen — a major component of skin. This process generally occurs within 4 to 6 weeks.
Of course, the healing time depends on a wide range of things; not every wound is the same and neither are any two people. The wound healing process depends on the state of your immune system, of the wound, and of the ocean. In addition to this, other factors such as oxygenation of the wound, presence of infection, age of the individual, sex hormones, stress, diabetes, obesity, medications, alcoholism, smoking, and nutrition can extend healing time.
A specific form of saltwater known as saline has long been used in the field of medicine to clean wounds. And many of us are familiar with the advice of swimming in the ocean to help the wound heal faster. I know what my mother says about the subject, but what does the science say?
First, it is important to distinguish between saline and seawater. Saline consists of water and 7% sodium chloride (ie. regular table salt). In contrast to this, seawater consists of water and salt in addition to a wide range of microorganisms, bacteria, and even viruses. The different compositions of saline and saltwater have different implications for the wound healing process.
It is believed that the 7% salt concentration in saline has a drying effect on the wound that causes the growth of new tissue to accelerate. A study conducted on mice found that mice who had their wound soaked in water with 7% salt concentration had a smaller wound diameter on the 3rd day and healted faster compared to the control group. However, before we jump into the ocean to heal out cuts and scrapes, we have to consider the implications of the bacteria and viruses present in seawater. Swimming in the ocean with an open wound presents an opportunity for bacteria to enter the wound and cause an infection. This is particularly relevant for oceans in tropical climates and beaches that are near a treatment plant. Furthermore, people with health conditions such as diabetes or liver cancer, or those undergoing treatments that weaken the immune system can be at a higher risk of acquiring an infection when swimming with an open wound in the ocean.
With minor wounds, it is recommended that they are covered when swimming and cleaned right after swimming to remove any contaminants from the wound. For larger wounds, it is recommended that you speak with a healthcare professional before going for a summer swim.
I went swimming with my wound before knowing this information and luckily my wound healed perfectly! However, I was extremely cautious. I made sure to cover the exposed skin with a sealed band-aid when swimming and as soon as I got out of the water I would clean out the wound and apply a new dressing! If I had a bigger wound and knowing what I know now, I am not so certain I would still go swimming in the seawater – no matter how hot the day is!
Daniela is a recent B.Sc. graduate from the program of Physiology at McGill. She is very passionate about understanding the human body and how we can all individually adapt our daily lifestyles to improve its functioning.
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