Bone drugs linked to lower Alzheimer's risk in study of 121,000 older adults

A large observational study of 121,492 adults age 60 and older found that nitrogen-containing bisphosphonates, a class of drugs widely used to treat osteoporosis, were associated with a 16% lower risk of Alzheimer's disease and related dementias compared with patients who took no osteoporosis medication. Against patients on other osteoporosis drugs, the risk gap reached 24%. The study, published in Alzheimer's & Dementia, stops short of claiming the drugs prevent dementia, and the authors are calling for a clinical trial to confirm the signal.

The research was conducted in Hong Kong. Every participant had recently been diagnosed with osteoporosis or had suffered a serious fracture in the spine, humerus, wrist, or hip, and none had previously received osteoporosis medication. Common nitrogen-containing bisphosphonates include alendronate, ibandronate, risedronate, and zoledronate.

The bone-brain connection

Ching-Lung Cheung, associate professor in the Department of Pharmacology and Pharmacy at the University of Hong Kong's Li Ka Shing Faculty of Medicine and a study author, pointed to what researchers call a "bone-brain axis." The idea is that bone health and brain health are closely connected. His group's prior work, and research by others, found that people with low bone mass or osteoporosis are more likely to develop dementia later in life, Cheung told Fox News Digital.

The study's design is observational, which means the association cannot be taken as proof that bisphosphonates reduce dementia risk. Cheung was explicit: confirmation in a clinical trial is required before the finding can be considered established. Generalizability also remains an open question, since all participants came from a Chinese population.

Limitations and what comes next

The researchers lacked baseline cognitive testing data, raising the possibility that patients who had already begun to experience cognitive impairment were less likely to receive osteoporosis treatment. They also had no information on osteoporosis severity or fracture severity, and no data on participants' use of over-the-counter calcium or vitamin D. External factors including education level, social isolation, air pollution, and vision loss could have influenced the dementia outcomes.

Although the association with lower dementia rates is present in the data, the authors said prescribing bisphosphonates specifically to prevent or treat Alzheimer's disease is not yet warranted. The next step Cheung identified is a clinical trial, with attention to whether gender plays a role in the observed risk reduction.