This Popular Food Preservative Could Undermine Your Flu Shot

A popular food preservative used with foods like potato chips may reduce the effectiveness of the flu vaccine, according to new research. The compound isn't always listed on a product's ingredients list, making it difficult for the public to avoid. Consuming the substance may hinder the flu vaccine's efficacy by altering the immune response in people who were vaccinated.

The flu vaccination remains a critical tool for reducing the spread and severity of influenza, but it isn't 100-percent effective. Some individuals who receive the flu vaccination will still contract the illness, though they often recover from it more quickly. Different factors impact the vaccine's effectiveness, and a particularly common food preservative called tert-butylhydroquinone (tBHQ) may be one of them.

This food preservative is commonly found in frozen meat and fish, cooking oil, and processed foods including snacks like crackers and potato chips. Eating food containing this preservative may result in an altered immune response that makes the flu vaccine less effective.

Robert Freeborn, one of the study's leads, explained:

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. We determined that when tBHQ was introduced through the diet, it affected certain cells that are important in carrying out an appropriate immune response to the flu.

The study involved mice who were fed food containing the tBHQ preservative in quantities similar to what a human may consumer. The researchers noted a reduction in the number of cells that could identify the flu virus; there was also evidence that the preservative may decrease one's ability to fight off the virus in its earlier stages.

As a result, the virus may be able to "run rampant" in the body of someone who consumes this food preservative before their immune system gets to work combating it. The study found that tBHQ may impair an immune system's ability to "remember" how it should respond to the flu virus, which could potentially increase weight loss and recovery time, as well.