Cheers,” a woman says in a video on TikTok as she raises a shot glass filled with liquor to the camera. She tips it back, grimaces and then sticks out her tongue in disgust.

“It’s medicinal; it’s medicinal,” she reminds herself.

The reason for the shot was a recent meal, which she worried may have given her food poisoning, she said. And she had read in a study that because “alcohol is a steriliser”, it can protect against food-borne illness.

But can it really?

There might be an ounce of truth to the notion that drinking alcohol around the time you eat contaminated food can reduce the chances of food poisoning, experts said. But the evidence to support the claim is limited. And depending on how much you drink, alcohol could hurt your immune system more than it might help. Here’s what we know.

Several small studies on food-borne illness outbreaks have indeed found that consuming alcohol was associated with protection from food poisoning, but they all have limitations.

In the 2002 study cited in the TikTok video mentioned above, researchers described a salmonella outbreak that began at a 120-person banquet in Spain. At least 47 people became ill with vomiting or diarrhoea, along with stomach cramps, fever or headache, after consuming contaminated tuna sandwiches and potato salad. The researchers found that those who reported having three or more drinks at the celebration were 46 per cent less likely to become ill than those who didn’t drink, and those who had up to three drinks were 27 per cent less likely to develop symptoms.

Likewise, in a 1992 study of a 61-person outbreak of hepatitis A from raw oysters in Florida, US, researchers found that those who reported drinking wine, whiskey or cocktails with the oysters were 90 per cent less likely to get sick than those who did not drink. Those who consumed beer, however, did not seem to be protected — the researchers hypothesised this was perhaps because beer has a lower
alcohol concentration than the other beverages.

These studies support the theory that alcohol might interrupt the pathogens in people’s guts before they can cause illness, said Donald Schaffner, a professor of food science at Rutgers University in New Jersey, US. This is plausible, he said, since alcohol can kill bacteria and inactivate some viruses; that is why it is used in hand sanitisers and surface disinfectants.

But these small, decades-old studies can only show correlations between drinking and fewer illnesses; they can’t prove that alcohol prevented food poisoning, said Matthew Moore, an associate professor of food science at the University of Massachusetts Amherst in the US.

He recommended taking those findings “with a serious grain of salt”.

It’s possible, for example, that some of the people who didn’t drink in those studies were abstaining for health reasons, which could have explained why they were more susceptible to food poisoning.

Researchers have not directly tested how drinking might influence food poisoning risk in a clinical trial, which could control for differences between people who do and don’t drink, Moore said. And in at least one outbreak of 33 people sickened with hepatitis E from shellfish on a cruise, researchers came to a different conclusion: only those who drank alcohol were infected while the abstainers remained healthy.

Your chance of getting sick from contaminated food can depend on various factors, including your health, the amount of pathogen present, the type of food and how much of it you ate, said Craig Hedberg, an epidemiologist and food safety expert at the University of Minnesota, US. How alcohol plays into that is not well researched in humans, he said. But in a 2001 study, scientists found that although red and white wine killed salmonella in petri dishes, feeding it to mice did nothing to protect them when they consumed the bacteria.

If you drink too much, it’s also possible that alcohol might make your intestine more susceptible to infections, said Dr Gyongyi Szabo, a gastroenterologist and professor of medicine at the Harvard Medical School in the US.

Research from Dr Szabo and her colleagues has suggested that binge drinking — defined as four to five or more drinks in about two hours for most adults — can cause inflammation and signs of “leakiness” in the gut lining, which can allow bacteria and toxins to more easily enter the blood.

It’s also clear that heavy, chronic drinking can reduce your immune system’s ability to fight infections, she said. Research has shown, for example, that people with alcohol use disorder are more susceptible to illness or even death from certain food-borne infections such as listeria and vibrio.

And alcohol can cause dehydration, which may worsen food poisoning symptoms and prolong recovery time, experts said.

Drinking alcohol is an unproven and potentially risky approach to preventing food poisoning, experts said.

“It would be better just to not eat the dodgy food to begin with,” said Schaffner.