Most medicines can cause side effects, like headaches or upset stomach. Sometimes, a side effect can be a good surprise. New research suggests that the vaccine for shingles might also lower the chance of getting dementia.
What is shingles?
Shingles is a painful rash caused by the same virus that gives us chickenpox. The virus hides in our nerves after chickenpox and can wake up years later as shingles. Doctors recommend the shingles vaccine for people 50 or older, and for younger people with weak immune systems.
Link between shingles vaccine and dementia
Studies show that having shingles may raise the chance of dementia later on. Because of this, scientists have checked if stopping shingles with a vaccine also cuts down dementia risk. Here are some findings:
- One study of over 300,000 adults found that people 70 and older who got the shingles vaccine had less dementia than those who did not get it.
- Another study compared two types of shingles shots. Both shots lowered dementia risk over six years, but the newer shot gave more protection—about five and a half months more dementia-free time.
How a natural experiment gave more proof
A “natural experiment” looks at what happens when people get or don’t get a treatment by chance. In Wales, in 2013, only people born on or after September 2, 1933 could get the shingles shot at that time. Scientists used health records of nearly 300,000 people born just before or after that date. Over seven years they saw that those who got the vaccine:
- got shingles less often
- were 3.5% less likely to get dementia (about a 20% drop)
- had even more benefit if they were women
This type of study can’t prove cause and effect, but taken with other studies, it strongly suggests the vaccine helps protect the brain.
Why might it work?
There are some good ideas on how the vaccine could slow or stop dementia:
- Less inflammation in the body and brain because shingles is prevented.
- A stronger or better-balanced immune response after the shot.
- Fewer strokes, since shingles can raise stroke risk and strokes can lead to dementia.
Scientists still want to learn why women seem to get more protection, and whether the vaccine works better for some types of dementia than others.
What should you do?
You can lower dementia risk in many ways: eat well, stay active, and keep your mind busy. The shingles vaccine looks like another good step, especially if you are 50 or older or have a weak immune system. It can prevent painful shingles and might help keep your mind sharp.