A common food additive may make the influenza vaccine less effective

ORLANDO – A common food additive can make it more difficult to fight the flu.

The vaccinated mice that received food containing the additive, tert-butylhydroquinone (tBHQ), took three more days to recover from the flu than mice that ate food without tBHQ. The unpublished result suggests that the common additive could make influenza vaccines less effective, said toxicologist Robert Freeborn of Michigan State University in East Lansing at the 2019 meeting on experimental biology.

The additive helps stabilize fats and is used as a preservative for a wide variety of foods, including cooking oils, frozen meat products – especially fish fillets – and processed foods. such as crackers, chips and other fried snacks. Food manufacturers do not have to put the ingredient on the labels. So it's "hard to know everything," says Freeborn.

In separate experiments, unvaccinated mice eating tBHQ in their food had more RNA-based virus in the lungs than mice that did not eat it. TBHQ eaters also had inflammation and increased mucus production deeper into their lungs than usual, found Freeborn and his colleagues.

Researchers do not know exactly how this additive hampers the fight against the flu, but it may be because it increases the activity of an immune system protein called Nrf2. Increased activity of this protein could reduce the number of anti-virus immune cells in mice. This possibility remains to be tested.