Food additive in frozen meat, crackers worsens flu

A common food additive found in many products, including frozen meat, crackers and fried foods, could weaken the human immune system against flu, which accounts for 290,000-650,000 deaths globally every year, say researchers.

Besides increasing the severity of flu symptoms, the study found exposure to compound – tert-butylhydroquinone (tBHQ) – could reduce effectiveness of flu vaccine through its effects on T cells.

During the study, mice fed tBHQ-spiked diet were slower to activate both helper T cells and killer T cells, causing slower clearance of the virus.

"Our studies showed mice on a tBHQ diet had a weakened immune response to influenza infection," said Robert Freeborn, postdoctoral candidate at the Michigan State University.

"In our mouse model, tBHQ suppressed function of helper and killer T cells. It led to more severe symptoms during a subsequent influenza infection," Freeborn said.

When the mice were re-infected with a different but related strain of influenza, those on the tBHQ diet had a longer illness and lost more weight. This suggests that tBHQ impaired the "memory response" that typically primes the immune system to fight a second infection, Freeborn said.

Since tBHQ is not always listed on ingredient labels, the best way to limit tBHQ exposure is to be conscious about food choices. A low-fat diet and less consumption of processed snacks will help reduce tBHQ consumption, he suggested.