“So far, cardiovascular drugs overall are the most studied in relation to dementia risk, including medications used to treat high blood pressure, atrial fibrillation, and high lipid levels,” says Dr. Ding. The reason these have gained such attention is because the research has established strong connections between cardiovascular diseases and dementia, she explains.
One systematic review and meta-analysis of 55 observational studies involving more than seven million people found that statin use is associated with a 14 percent lower risk of dementia and an 18 percent lower risk of Alzheimer’s disease compared with not taking statins for cholesterol. Researchers say this may be linked with the drug’s ability to protect blood vessels in the brain and fight brain inflammation.
But the findings aren’t consistent. Previous reports show some statin users experience short-term cognitive decline — such as memory loss, forgetfulness, and confusion — so experts can’t say definitively whether statins have a positive impact on dementia risk.
“The evidence is not as strong as it is for blood pressure medications,” says Natasha Bhuyan, MD, a family physician who specializes in reproductive health at One Medical in Scottsdale, Arizona. “Some studies show that statins might have a moderate impact on dementia risk, which could be due to reducing inflammation and stabilizing blood vessels. But they shouldn’t be taken by people who don’t need them.”
Experts emphasize that future clinical trials are needed to better understand statins’ long-term effects on cognition.
4. Routine Vaccines
Certain routine vaccinations may offer an unexpected benefit beyond protecting against infectious diseases: They may also help support long-term brain health, with research linking several vaccines with a lower risk of dementia.
The strongest evidence so far is for the shingles vaccine. A 2025 study found that adults who received the vaccine were about 20 percent less likely to develop dementia over the following seven years than similar adults who weren’t vaccinated.
Other routine vaccinations — including annual flu shots — may also be associated with a lower dementia risk. A systematic review and meta-analysis found that those who got the influenza vaccination had a 13 percent lower risk of dementia than those who didn’t get the vaccine, though much of the evidence was observational and the studies differed considerably in their methods and findings, making it more difficult to draw firm conclusions about whether the vaccination itself lowered dementia risk.
Researchers are still working to understand the connection, but one theory is that vaccines may lower dementia risk by preventing infections that can trigger chronic inflammation and damage to the brain and blood vessels. “These are observational studies, so we can’t make a definitive conclusion, but [the shingles vaccine] has the most compelling and large-scale evidence,” Dr. Bhuyan says, noting that the shingles infection could damage brain cells and blood vessels. “So by preventing the infection, we are preventing the risk of dementia.”
Guo agrees that the findings are encouraging but should be interpreted cautiously, noting that vaccines should be taken according to public health recommendations, but not as proven dementia-prevention drugs.
5. SGLT2 Inhibitors
Researchers are also investigating whether SGLT2 inhibitors — medications used to treat type 2 diabetes, such as empagliflozin (Jardiance) and dapagliflozin (Farxiga) — may protect the brain by improving blood sugar control, reducing inflammation, and supporting heart health.
The evidence so far has been mixed. One recent review of available research found that SGLT2 inhibitor use in people with type 2 diabetes was consistently associated with a lower risk of dementia than in those not taking the medications. But a separate meta-analysis of 26 randomized clinical trials did not find a significant reduction in dementia risk with SGLT2s.
Guo says for people with type 2 diabetes, the findings that diabetes medications may contribute to lower dementia risk are promising, but not definitive. “However, randomized trial evidence remains limited, and we cannot assume the effect applies to people without diabetes,” she says.
Bhuyan agrees. “The evidence is not as strong here,” she says. “These medications likely have an impact on both blood sugar control and reducing the risk of heart failure, but they do not help people without diabetes.”
