Despite their tough outer skin, avocados should be washed before they are eaten to guard against the sickness-inducing bacteria listeria.
That is the advice of US federal agency the Food and Drug Administration, which tested 1,615 avocados for harmful bacteria and found that 17 per cent of the fruits’ skins tested positive for listeria monocytogenes.
The study, which began in 2014, also found salmonella bacteria present on less than one per cent of on avocado skins, and contamination of avocado pulps was similarly low, with just three out of 1,254 samples testing positive.
Despite the fact that the edible part of an avocado was rarely found to be contaminated, the FDA recommends that consumers wash the fruit thoroughly under running water to avoid bacteria from the skin being transferred to the inside of the avocado.
On it’s blog foodsafety.org, the FDA also suggests scrubbing firm produce such as an avocado with a clean brush to ensure all bacteria is removed and then “drying with a cloth or paper towel to further reduce bacteria that may be present."
Listeriosis, which the NHS describes as a “rare infection” caused by listeria, can cause fever, aches and pains, chills, vomiting and diarrhoea.