evidence: Fact check: Leaving raw onions around your house won’t prevent illnesses [...] An old wives' tale that keeping raw, unpeeled onions out will keep your family safe from illnesses such as the flu is making the rounds on Facebook. [...] We rate the claim that raw onions can help prevent illness or keep people healthy as FALSE, based on our research. Though onions have recognized health benefits, there is no scientific evidence that an unpeeled onion can absorb germs and protect from viruses or bacteria. It’s also false that onions are a magnet for food poisoning.