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Fudenberg, whose medical license was revoked in 1995.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.