Flu Shots and Alzheimer’s: Is There a Connection?
The connection between Alzheimer’s disease and flu shots has been a long a widely disputed one. In the 1990s, a doctor in the USA has been wrongfully spreading misinformation about vaccinations, claiming that they are capable of causing Alzheimer’s disease. According to Verywellhealth, “This idea may come from Dr. Hugh Fudenberg, whose medical license was revoked in 1995. Some internet sites credit him as the source who states that the flu shot increases the risk of Alzheimer's”.
The
former doctor’s false claims have spurred a negative attitude towards
vaccination in the general population. To double-check that flu shots
are safe to the public, a multitude of new studies have been conducted,
and all of them found that flu shots do NOT cause Alzheimer’s disease,
but they did find another very curious correlation. Starting from 2001,
studies started appearing that claimed the opposite was actually true
and vaccinations can lower one’s risk of Alzheimer’s. More on that
below.
How vaccines can help prevent Alzheimer’s Disease
In a surprising turn of events, the
outrage towards vaccinations has led to an exciting discovery that can
potentially help millions of people at risk of Alzheimer’s and dementia
protect themselves from cognitive decline. As of 2020, there are several
studies confirming that vaccinations can lower the risk of Alzheimer’s
disease.
The first study
of the kind was conducted in 2001 in Canada and researched the
population of 4392 adults 65 and older who were either vaccinated or
not, and they conclude that vaccination may actually lower one’s risk of
Alzheimer’s. Quoting the study, “Past exposure to vaccines against
diphtheria or tetanus, poliomyelitis and influenza may protect against
subsequent development of Alzheimer's disease”.
More recent research
coming from 2 different studies presented at the 2020 Alzheimer’s
Association Virtual International Conference further specifies the
positive effect of vaccines on brain health. In the first study
conducted at the University of Texas, researchers looked at the health
records of more than 9,000 seniors in the age range of 60 and older.
The
researchers found that even those who only received a flu vaccine once
in their lifetime had a 17% lower risk of developing Alzheimer’s. Those
who got two flu shots or got vaccinated regularly had even better
protection from the disease - a 30% percent lower risk.
The
second study found a very similar result. It was conducted in a
different part of the US as a joint project between Duke University and
the University of North Carolina. This research looked at 5,000 people
aged 65+, concluding that those who got a pneumonia vaccination at least
once before age 75 has a 25-30% lower likelihood to develop
Alzheimer’s. These findings are pretty impressive, and medical research
is now considering vaccination as a possible preventative treatment of
Alzheimer’s!
It
also needs to be said that flu and pneumonia vaccines are beneficial
not only as a preventative tool but also as a lifesaving treatment for
dementia and Alzheimer’s patients. This is because hospitalized dementia
patients are over six times more likely to die as a result of an
infection, and catching the flu or any other respiratory infection can
actually further worsen their symptoms and even lead to delirium.
Therefore, medical professionals stress the importance and great value
of yearly vaccinations for all seniors, especially dementia and
Alzheimer’s patients.
Why do vaccines help prevent Alzheimer’s?
Given
the relative novelty of these findings, researchers don’t really know
yet how exactly flu shots and other vaccines are capable of preventing
Alzheimer’s disease. They do point out, however, that many previous
studies have suggested that inflammation and recurrent infections may
increase one’s risk of dementia and cognitive decline. Influenza, or the
common flu, has been shown to cause this kind of long-term brain
inflammation, as shown in a 2018 study. This way, preventing influenza may also help put a stop to cognitive decline, too.
Certain research has even tried linking specific strains of bacteria, fungi, or viruses
to Alzheimer's disease, but the current consensus is that the brain
conditions are worsened by chronic inflammation and infections instead
of being directly caused by any specific microbe.
In
addition, recurring respiratory infections may be lowering your immune
system, which may also raise your risk of dementia. As Dr. Kaiser, the
director of Geriatric Cognitive Health for Pacific Neuroscience
Institute at Providence Saint John’s Health Center, stated to Healthline, “Getting
sick with the flu or pneumonia, particularly with bad cases, can be
taxing on the brain and increase your long-term risk of dementia. So
protecting yourself from flu and pneumonia, through vaccination, may
very well be protecting your brain too", and we completely stand by that
final piece of advice.