It is one of the first things many parents reach for when their child takes a tumble, but using Vaseline for cuts is a bad idea, researchers claim.
Petroleum jelly is recommended to ‘protect’ minor scrapes and cuts, and experts say it prevents scabs forming so injuries are less itchy, heal faster and leave smaller scars.
But a study led by the University of Leeds found Vaseline stops the body forming its own ‘natural plaster’.
This newly discovered natural plaster is a film of protein, a fiftieth the thickness of a human hair, that keeps out bacteria including E.coli and staphylococcus aureus.
Without it, there is a greater risk of skin infections. But petroleum jelly stops the reaction between blood and air needed to form the film.
Professor Robin Ariens, who led the study from the school of medicine, said: ‘People use petroleum jelly to prevent clotting, and in rugby and similar contact sports it is done to prevent excessive bleeding.
‘But it is better to leave the cut to heal with the body’s own protective barrier, which acts like a natural plaster. I would advise people to avoid using Vaseline or, if they really must, to use it half an hour after suffering a cut, since the film is then fully formed.
‘Vaseline only disrupts film formation but does not break it once formed.’ The American Academy of Dermatology recommends petroleum jelly for keeping a wound moist, so it does not dry out and form a scab, which takes longer to heal. This is said to prevent the scar left behind from getting too large, deep or itchy.
But when researchers used Vaseline on human blood clots and on mice, the oily substance blocked the body’s ‘natural plaster’ or biofilm. The film is part of the natural clotting process and provides protection for at least 12 hours. This is the time when a minor injury is most vulnerable to infection.
Unilever, the makers of Vaseline, responded to the findings published in the Journal of Clinical Investigation saying: ‘For over 140 years our Vaseline Petroleum Jelly has proven to be an effective product in locking in moisture and helping skin stay healthy.
‘It is widely recognised as a skin protectant, specifically in preventing the skin’s surface from drying out.’