It’s fall and unless you live in a bubble it’s hard to miss the plethora of advertisements urging us to get our annual flu shot.
Since flu season typically peaks in the January - February time frame, it may seem a little premature to worry about the flu, but flu outbreaks can occur as early as October and November.
While the annual vaccine may keep you hale and healthy during flu season, some researchers believe that the flu vaccine provides as added benefit -- protection against heart attack.
In a study led by Dr. Jacob Udell, a cardiologist at Women’s College Hospital and the University of Toronto, researchers found that people who received a flu shot had a significantly lower risk of heart attack and cardiovascular-related events at the end of the one-year follow-up period, compared to people who didn’t receive the flu vaccine.
Researchers reached their conclusions after re-examining and evaluating the results of four separate trials involving over 3,200 participants. The various studies took place between 1994 and 2008.
All participants were followed for a period of a year and included people from varied heath backgrounds, such as those free from heart disease, those with stable heart-disease, and people who’d suffered heart attacks or who'd had other cardiovascular-related events.
Approximately half the participants received flu vaccines while the others received placebos.
During the follow-up period, 200 participants suffered a heart attack or some other type of major cardiovascular-related event. In all, 65 cardiovascular-related deaths were reported during the follow-up period.
Researchers found that the rate of heart attack, and cardiac-related events was almost 50 percent less in participants who received the flu vaccine.
Researchers have two theories regarding why participants who received the flu vaccine fared so much better when it came to heart attack and cardiovascular-related events than participants who didn’t receive the vaccine.
Firstly, flu causes inflammation which is linked to increases in heart disease. By preventing flu, participants receiving the vaccine didn’t suffer increased inflammation which helped protect their heart.
Also, researchers believe that simply avoiding the flu may be enough to protect patients whose health is already compromised from suffering an illness that might be the one that causes them to “dip over the edge.” (US News. 1)
The findings are supported by the results of a separate study of 230 heart patients with cardiac defibrillators implanted, conducted at the Sunnybrook Health Sciences Centre in Toronto. People with cardiac defibrillators generally report receiving more shocks from the defibrillator during flu season than at other times of the year.
The Sunnybrook study found that only 11 percent of patients receiving the flu vaccine reported receiving defibrillator shocks during flu season. Fourteen percent of those who didn’t receive flu shots reported receiving one or more defibrillator shocks during the same time period.
It would be nice if the flu shot were simply a vaccine which also prevented heart disease but this isn’t the case. However, if you’re on the fence about whether or not to get a flu vaccine this year, keep in mind that your annual flu vaccination just may be preventing more than the flu.
Kathleen Doheny. Flu Vaccine May Protect Your Heart. US News & World Report. 28 Oct 2012.
Heart and Stroke Foundation of Canada (2012, October 28). Influenza vaccine may reduce risk of heart disease and death: Flu shot may reduce risk of major cardiac event by 50 percent. ScienceDaily. Retrieved October 28, 2012, from
Seasonal Influenza: The Flu Season. Centers for Disease Control and Prevention. 12 Oct 2012.
Reviewed October 29, 2012
by Michele Blacksberg RN
Edited by Jody Smith