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Older adults who got two shots of the shingles vaccine had less than half the rate of dementia compared to those who didn’t get the vaccine—so the shingles shot might be linked to a lower risk of memory problems.
Correlational
People who got two shots of the shingles vaccine were about half as likely to develop dementia later on, no matter how old they were or what race or ethnicity they belonged to.
Getting two shots of the shingles vaccine doesn’t seem to increase or decrease your risk of getting dementia — and any link people thought they saw was probably just a fluke in how data was collected, not because the vaccine actually affects the brain.
People who got the shingles vaccine twice were less likely to develop dementia later on than people who got a different vaccine (Tdap), and this isn’t just because they’re generally healthier or more likely to visit the doctor — the shingles vaccine might be doing something special to protect the brain.
People 65 and older who got two shots of the shingles vaccine were about half as likely to be diagnosed with dementia later on, compared to those who didn’t get the vaccine — but this doesn’t prove the vaccine prevents dementia, just that the two are linked.
Researchers found that people just above and just below the age cutoff for getting the shingles vaccine were pretty similar in their health before getting the shot—so any differences in outcomes later are likely due to the vaccine, not pre-existing differences.
Descriptive
Getting the shingles vaccine didn’t make people start going to the doctor more for other things or change how they took care of their health overall—so if people who got the vaccine had less dementia, it’s probably because the vaccine itself helped, not because they became healthier in other ways.
In Australia, when people turned the right age to get a free shingles shot, way more of them got it than people who were just one year younger and didn’t qualify yet—so making the vaccine free at that age really worked to get more people vaccinated.
Causal
People who were eligible for the shingles vaccine seem to be less likely to get diagnosed with dementia later on—and this link holds up no matter how researchers tweaked their study rules, which makes it look pretty real.
Scientists compared people who were just barely eligible for the shingles vaccine with those who were just barely ineligible—and found they were equally healthy in other ways, so any differences in health later on can likely be blamed on the vaccine, not other factors.
Getting the shingles vaccine didn’t make people go to the doctor more for other things or change how often they were diagnosed with common long-term illnesses like diabetes or high blood pressure—so if people who got the vaccine had less dementia, it’s probably because the vaccine itself helped, not because they got better overall care.
When the government decided who could get a shingles shot based on birth date, people born just after the cutoff date were way more likely to get vaccinated—13% more—because the rule suddenly let them in, showing the policy worked as intended.
People born right after November 2, 1936, got a free shingles shot when they turned 60, and over the next 7.5 years, fewer of them got dementia than people born just before that date—suggesting the vaccine might help protect the brain.
Taking a supplement called betaine can lower a substance in your blood called homocysteine, which is linked to a higher chance of getting Alzheimer’s—so this supplement might help protect your brain.
Taking a daily vitamin and mineral pill for two years might help older adults think more clearly and remember things better—like turning back their brain’s clock by two years.
If you're older and have trouble hearing, using hearing aids might help keep your brain sharper and lower your chances of developing dementia.
A form of lithium called lithium orotate may help fix low lithium levels in the brain, slow down harmful brain changes linked to Alzheimer’s, and even clean up the sticky proteins that cause memory problems in mice.
Mechanistic
Some vaccines made with weakened viruses don’t just protect against the specific disease—they might also give your whole immune system a boost that could help protect your brain from damage, unlike other vaccines that only target one part of the virus.
People in their late 70s who got the shingles shot were 20% less likely to develop dementia over the next seven years compared to those who didn’t get it — that’s about 3.5 fewer cases of dementia per 100 people.
If kids born just before and after a vaccine eligibility cutoff get vaccinated at different times, scientists can compare them to see if getting the vaccine early helps prevent dementia later in life — like a real-life experiment without random assignment.
Getting the shingles shot when you're 65 or older might help lower your chances of developing dementia by about a third over the next several years.
If you can stop the chickenpox virus from waking up again in your nerves, it might calm down brain swelling and reduce harmful protein buildups that lead to memory problems and dementia.
When a virus infects the brain, it can cause swelling and inflammation that makes the brain produce too much of a sticky protein called amyloid-beta, which clumps together and damages brain cells faster, leading to memory loss and dementia.
Taking a daily supplement called betaine (4–6 grams) can quickly lower a substance in your blood called homocysteine—within about a month—and keeping it up keeps the levels low.