Could An Additive In Fish And Chips Stop Your Flu Vaccine Working? Here's What You Need To Know
A new study has found a link between a commonly-used food preservative and an altered immune response that could change the efficacy of the flu vaccine.
The study, published in the Faseb Journal, explores the effect of Tert-Butylhydroquinone (TBHQ) on the efficacy of the flu vaccine.
TBHQ is found in a number of commonly-used products including varnishes, lacquers, resins, and perfume. It is also added to frozen fish and fish products, as it can extend the product's shelf life.
The researchers found in experiments with mice that exposure to TBHQ at a dose comparable to low levels of human consumption led to an increase in proteins that suppressed normal immune response to flu infection.
In addition, the study found that this impairment of immune function also correlated with more severe weight loss and a longer period of infection, when the mice got the flu repeatedly or were infected by other strains of the virus.
Exposure to TBHQ depleted the number of CD4 T cells and CD8 T cells, both of which are integral to the cascading functions of the immune system.
That is to say, the TBHQ appeared to erase the memory capacity of the mice immune response, and they couldn't 'learn' to fight the flu after exposure.
Robert Freeborn, one of the study's authors, stated the TBHQ impact was concerning for flu vaccine programs.
"If you get a vaccine, but part of the immune system doesn't learn to recognise and fight off virus-infected cells, then this can cause the vaccine to be less effective," Freeborn said.
The flu is thought to be responsible for up to 650,000 deaths worldwide every year, and public health bodies are extremely concerned about the genetic changes to flu strains such as H5N1 (bird flu) that could cause epidemics in the future.
Does this mean you should give up frozen fish if you want to combat the flu?
As the study was only conducted in mice, it is not yet clear what the implications for human immune response may be.
While mice and humans appear to share a majority of immune system genes, mice can't provide a perfect replication for what will happen in people.
One study from Harvard Medical School in 2013 found that while CD4 T cells were unchanged between mice and humans, there are differences in the functioning of CD8 T cells -- so the jury is still out on whether or not the same immune effects will be seen in humans.
TBHQ is a synthetic antioxidant and in recent years, it's been the subject of a large amount of contentious online articles from lifestyle and health bloggers, claiming that it is 'toxic' and a known 'carcinogen'.
It's also been a target of particular concern from health groups because companies do not have to disclose its use in ingredient lists.
Both the US Food and Drug Administration (FDA) and the European Food Safety Authority classify TBHQ as a safe food additive.
While TBHQ has been consistently linked to cancer development in online wellness discussions (and there have been studies to show that chronic exposure during factory production could increase cancer risk) extensive studies have shown the compound actually has an anti-carcinogenic (cancer-fighting) effect in the body.
Research has even found that TBHQ can reduce injury and intestinal inflammation following traumatic brain injury.
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