Flu Vaccine May Cut Heart Attack Risk


The flu vaccine may lower your risk for heart disease and stroke

A new study published in the Journal of the American Medical Association Internal Medicine  shows that getting a flu vaccine may reduce the risk of suffering a heart attack or stroke.

“We may have identified that the flu vaccine may also be a vaccine against heart attacks,” says lead author Jacob Udell, a cardiologist at Women’s College Hospital and a scientist at the University of Toronto.

Udell and colleagues analyzed six studies dating back to the 1940s concerning the heart health of more than 6,700 men and women with an average age of 67. Half got a flu vaccine; half got a placebo shot or nothing. About a third had heart disease and the rest had risk factors such as high blood pressure, high cholesterol, diabetes and smoking.

Their major findings showed that people who had received the flu shot were:

  • About 36% less likely to experience heart disease, stroke, heart failure or death from cardiac-related causes.
  • About 55% less likely to suffer a cardiac event if they had recently experienced a heart attack or stroke.

“Our study provides solid evidence that the flu shot helps prevent heart disease in vulnerable patients — with the best protection in the highest risk patients,” Jacob Udell said.

How the flu shot helps

Udell offers several theories as to how the flu shot may help prevent heart disease and cardiac events. One is the “vulnerable plaque theory,” which asserts that inflammation caused by the flu “may turn a stable plaque into an unstable plaque and cause a cardiac event.”

Plaque is the result of a buildup in the lining of the arteries of fatty substances, cholesterol, calcium and fibrin (a clotting material in the blood).

Another is the “vulnerable patient theory.” This suggests that the side effects from the flu, such as coughing, low oxygen, low blood pressure, fast heart rate and possible pneumonia, may strain the heart and cause a cardiac event, he says.

According to Udell, the study offers one more good reason to get a flu shot.

The CDC recommends that everyone above the age of six months get the flu vaccine. In fact, all major health organizations recommend that people with heart disease get the influenza vaccine, says cardiologist Mariell Jessup, president of the American Heart Association. “However, this kind of data underscores the risk of death from the flu and how it can be prevented.”