A RECENTLY REPORTED STUDY SHOWS THAT FLU vaccination is associated with a nearly halving (40 percent drop) in the risk of Alzheimer’s disease over four years.

Could reducing your risk of suffering from dementia be as simple as getting a jab? Historical research suggests vaccinations may confer some protection against cognitive decline.

To better understand whether vaccination is protective, researchers at The University of Texas Health Science Center at Houston (USA) analyzed over 9,000 health records.

Let’s explore the relationship between our immune system and cognitive decline before turning to the new study suggesting that a flu shot may lower Alzheimer’s risk.

Immune system and Alzheimer’s: Background

Systemic immune responses can have long-lasting brain effects and modulate Alzheimer’s risk.

The available research demonstrates a lower chance of developing dementia with previous exposure to various adult vaccinations. Examples include tuberculosis, diphtheria, tetanus, pertussis, polio, shingles (herpes zoster), and influenza vaccinations.

On the other hand, a higher probability of cognitive decline is associated with various infectious diseases. Such conditions include the flu, herpes infections, chronic periodontitis, COVID-19 infections, pneumonia, and more.

While flu vaccination appears to lower the risk of dementia, we have not historically had a large sample representing the general United States population. Researchers thus sought to determine if an association between influenza vaccination and Alzheimer’s disease exists in a group of insured 65-and-older adults.

Immune system and Alzheimer’s: New evidence

Researchers used existing claims from patients 65 years and older. None had dementia during the six-year look-back period.

The study authors created two groups: The first cohort had received the flu vaccine while the second group had not. After matching for demographics, medications, and health conditions, researchers discovered these findings:

Patients who received at least one flu vaccination had a 40 percent lower chance of developing Alzheimer’s disease over the four-year follow-up period than those who had not received the vaccine.

The risk appeared lowest in those who had received a flu vaccine every year over the six-year look-back time frame.

While the study results confirm previous findings that flu vaccination is associated with a lower risk of Alzheimer’s disease, caregivers do not yet recommend using the flu vaccine as a tool to reduce dementia risk. Association is not causality, as my readers know.

I am delighted that my annual flu shot is associated with more than a reduction in my chances of getting the flu. Thank you for joining me in looking at the relationship between influenza vaccination and Alzheimer’s disease risk.