New research has found that not only can flu be a threat to a person’s health in the present, it could also put them in danger of contracting serious illnesses in the future.

Researchers at Columbia University in New York City found that flu can increase your odds of having a stroke by almost 40% – with that increased risk remaining for a full year. The study involved nearly 31,000 patients from a New York state database who had a stroke in 2014, with an average age of 72. The researchers expected to find variations in stroke risk relating to factors such as where people lived, and whether they were male or female, but instead noticed that stroke risk commonalities following a person fighting the flu became apparent.

Connecting the flu and strokes

Researchers found that as a group, the study participants tended to have experienced severe cases of the flu, with many visiting A&E or being admitted to hospital as a result – forming connections between stroke sufferers and a history of influenza.

The lead researcher from Columbia University explained the connection, and highlighted the length of time for which it continued. “The risk is highest in the 15 days of influenza, and starts to decrease as time goes on,” she explained.

Another expert from Lennox Hill Hospital in New York City commented on the study, saying that the prolonged risk, which goes on for “several months”, is particularly interesting – going on to theorise that the inflammation caused by infections like the flu could be what leaves the body vulnerable to conditions like strokes. “The flu puts your immune system into overdrive and you’ve got a lot of inflammation, and it persists,” he said. “It’s not a one-and-done risk — the risk is there for several months.”

Coming to conclusions

For the second part of the study, another group of Columbia University researchers used the same data to identify patterns among 3,900 cases of cervical artery tearing in men and women. They found that in the month following a case of the flu, patients had an increased likelihood of tearing neck arteries.

Within the data, the team also identified 1,700 cases of flu, and 113 cases where patients had experienced a bad bout of flu during the three years before suffering from a torn neck artery. “Previous studies have shown that non-traumatic cervical artery tearing is a leading cause of stroke in patients aged 15 to 45 years old,” said the lead researcher. “However, how dissections of the neck arteries occur without major trauma remains unclear.”

This second half of the study points to a connection between these types of artery tearing and the flu, with the association fading over time – suggesting that influenza could well be the trigger for this type of sudden artery injury.

Protecting yourself

One thing that did appear consistent throughout all areas of the study was the unwavering advice from experts prompting people to get a flu jab. Researchers stated that not only can a flu vaccination protect you against infection from the virus, but it may also help to reduce any risk of you contracting some of these serious complications.

A professor of medicine at New York University School of Medicine in New York City reviewed the findings of the study, agreeing that the vaccine is a solid preventative measure. “Flu causes a hyperimmune response and can increase clotting and wear-and-tear on the arteries,” he said – going on to explain that the problem with flu isn’t just the flu itself, but rather that it opens the door to other life-threatening diseases. “I would expect complications like these, which are extreme, to be less with flu shots,” he explains.


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