People with high blood pressure tend to have a lower risk of developing Alzheimer’s disease, but it may actually be because of the medicine patients take, not high blood pressure itself.

A study involving 17,008 Alzheimer’s sufferers and 37,154 patients who didn’t have the degenerative brain condition looked closely for links between Alzheimer’s and other health conditions, including high blood pressure and other ailments like diabetes and cancer, according to an Economic Times report.

They found that the only significant relationship was between higher systolic blood pressure and a lower Alzheimer’s risk — however, this may be due to the anti-hypertension medication that people with high BP tend to take. That means simply having higher blood pressure may not actually be the cause of the lower risk — although it could play a part, said Paul Crane, associate professor of internal medicine at the University of Washington and a co-author of the study, according to the report.

It’s the most authoritative paper to published on the causal relationships between Alzheimer’s and other diseases, and certainly is the largest with the most data points. If scientists can better understand correlation between Alzheimer’s and other ailments, it could lead to breakthroughs in treatments and a better understanding among scientists about what causes Alzheimer’s and what are some other modifying factors.

The findings were published in the journal Plos Medicine.

Alzheimer’s is one of the most significant health issues facing humanity today. This neurodegenerative disease gets worse over time and can result in the loss of memory and the ability to perform cognitive tasks. The elderly are most at risk of it, and it accounts for about two-thirds of all cases of dementia.