A stroke is a dangerous condition that happens when blood can’t reach the brain. It’s like a traffic jam in your blood vessels—without blood flow, brain cells start to die. Most strokes are caused by a blockage in the blood vessels that supply the brain. These are called ischemic strokes, and they make up the majority of stroke cases.
Now, scientists in Spain have found an interesting connection between the flu shot and a lower risk of having a stroke.
The flu shot is a vaccine that helps protect you from the influenza virus, which is more common in colder months. It doesn’t just keep you from getting sick—it may also help with other health problems.
Some past studies have shown that getting the flu can raise your chances of having a stroke, especially if you already have health issues like high blood pressure or heart disease. But could the flu vaccine actually lower the risk of stroke? That’s what Dr. Francisco J. de Abajo and his team wanted to find out.
The researchers used health records from people in Spain over a period of 14 years. They studied a group of 14,322 people who had strokes and compared them to 71,610 people who did not. These two groups were matched by age and gender, to make the comparison fair.
Then, the team checked whether these people had gotten a flu shot at least two weeks before their stroke, or before a similar date for those without strokes.
What Did They Find?
Here’s what they discovered:
- 41.4% of stroke patients had received the flu shot.
- 40.5% of non-stroke patients had also received it.
At first glance, the difference doesn’t seem big. But there’s more to the story.
The people who got the flu shot were often older and had more health conditions, like high blood pressure and high cholesterol. These are things that usually increase stroke risk. But even after adjusting for these factors, the scientists found something surprising: people who got a flu shot were 12% less likely to have a stroke than those who didn’t.
They also looked at whether the pneumonia vaccine had a similar effect, but they didn’t find any link between that vaccine and stroke risk.
Dr. de Abajo believes this is more good news for people who get the flu shot each year. If you’re at a higher risk of stroke—because of age, high blood pressure, or other health problems—then getting your yearly flu vaccine might help protect you in more ways than one.
However, it’s important to remember that this was an observational study. That means the researchers looked at real-life data, but they didn’t run a controlled experiment. So they can’t say for sure that the flu shot causes the lower stroke risk.
There might be other reasons that people who get flu shots are less likely to have strokes—like seeing doctors more often, eating healthier, or taking better care of their health in general.
Still, this study adds one more possible benefit to getting your annual flu shot. It’s a simple and low-cost way to protect yourself—not just from the flu, but possibly from other serious conditions like stroke.
As always, talk to your doctor if you have questions about vaccines or your stroke risk. And if you’re looking for more ways to protect your brain, other studies suggest that healthy diets—especially those rich in flavonoids (found in fruits, vegetables, tea, and chocolate)—may also help reduce stroke risk and support brain health.
The full study can be found in the journal Neurology.
If you care about stroke, please read studies about how to eat to prevent stroke, and diets high in flavonoids could help reduce stroke risk.
For more information about health, please see recent studies about how Mediterranean diet could protect your brain health, and wild blueberries can benefit your heart and brain.
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