New research warned that an additive found in common food, including crackers, suppress the immune system, making people more susceptible to the flu virus.
Moreover, researchers revealed that exposure to tert-butylhydroquinone or tBHQ can inhibit the effects of the flu vaccine.
The findings, which will be presented at the 2019 Experimental Biology meeting in Florida this week, might explain why seasonal influenza remains a threat to public health.
Common Food Additive Linked To Weakened Immune System
According to the researchers, tBHQ directly affected the function of the helper and killer T cells which respond to the influenza virus when a person is infected. The helper T cell tracks down the infected cells. Meanwhile, the killer T cell clears the infection from the body.
However, in mice models, the tBHQ suppressed both types of T cells. After feeding the lab mice with food that contained the common additive, researchers found that the helper and the killer T cells responded slower, which meant that the infected lab mice took longer to recover.
"Right now, my leading hypothesis is that tBHQ causes these effects by upregulating some proteins which are known to suppress the immune system," explained Robert Freeborn, a Ph.D. candidate at the Michigan State University. "Expression of these proteins, CTLA-4 and IL-10, was upregulated in two different models we use in the lab."
Further research is needed to confirm the hypothesis.
The researchers also found that the mice who were fed food spiked with tBHQ were reinfected with a different but related strain of the influenza virus. This implies that the memory response of the immune system was also compromised.
Vaccines rely on the memory response of the immune systems which might mean that if the person consumes food with tBHQ, its effectiveness might also be affected.
tBHQ In Everyone's Diet
The Centers for Disease Control and Prevention stated that the current flu season is not winding down and will likely be relatively long. In its most recent surveillance report, the public health agency reported that influenza-like illness activity across the United States remains above the national baseline.
Unfortunately, the influenza virus seems inescapable. The researchers said that it would be difficult to avoid tBHQ because the food additive is not often listed as an ingredient. It is also found in common food consumed by the public, including frozen meat and oil used for frying.
The researchers suggested that being picky about food and opting for prepackaged treats might help fight the influenza virus.
"Since tBHQ is largely used to stabilize fats, a low-fat diet and cutting down on processed snacks will help reduce tBHQ consumption," Freeborn added.