High BP linked to reduced Alzheimer's risk

People with a genetic tendency to high blood pressure (BP) have a lower risk for Alzheimer's disease, a new study has found.

But the connection may have more to do with anti-hypertension medication than high blood pressure itself.

"It's likely that this protective effect is coming from antihypertensive drugs," said co-author John Kauwe, associate professor of biology at Brigham Young University, US.

The study analysed genetic data from 17,008 individuals with Alzheimer's and 37,154 people without the disease.

The team looked for links between Alzheimer's disease and a number of health conditions -- including diabetes, obesity and high cholesterol.

But the team only found a significant association between higher systolic blood pressure and reduced Alzheimer's risk.

"Our results are the opposite of what people might think," said co-author Paul Crane, associate professor of internal medicine at University of Washington.

"It may be that high blood pressure is protective or it may be that something that people with high blood pressure are exposed to more often, such as antihypertensive medication, is protecting them from Alzheimer's disease," Crane said.

"This is to date the most authoritative paper looking at causal relationships between Alzheimer's disease and these potentially modifiable factors. In terms of the number of samples, it can't get bigger at this point," Kauwe said.

The study appeared in the journal Plos Medicine.