A new study suggests eating a preservative used to prepare foods like fish and chips could weaken the effects of the flu vaccine.

A common food additive used in cooking oils, frozen meats and fast foods such as fish and chips could lower the benefits of a flu vaccine, an international research study suggests.

Michigan State University scientists made the link after finding the preservative Tert-butylhydroquinone or tBHQ altered the immune response to the virus in mice.

"If you get a vaccine, but part of the immune system doesn't learn to recognize and fight off virus-infected cells, then this can cause the vaccine to be less effective," Robert Freeborn, a fourth-year doctoral student who led the study with Cheryl Rockwell, an associate professor in pharmacology and toxicology, said.

Professor Robert Booy, Head of the Clinical Research team at Australia's National Centre for Immunisation Research and Surveillance, described it as "tantalising research".

"It's not yet been tested on humans but in further research, I would be very keen to see if our favourite fish and chips is actually helping to make us sick," he told News Corp on Wednesday.