Popular Bone Health Drugs Linked to Lower Alzheimer’s Risk, Study Finds

Common medications used to treat osteoporosis have been linked to a significantly lower risk of Alzheimer’s disease and related dementias, according to a new study involving more than 121,000 older adults.

Researchers found that people taking nitrogen-containing bisphosphonates, a widely prescribed class of osteoporosis medications, had a 16% lower risk of developing Alzheimer’s disease and related dementias compared with people who were not taking osteoporosis medication.

The association was even stronger when the drugs were compared with other osteoporosis treatments. Patients taking nitrogen-containing bisphosphonates had a 24% lower risk of Alzheimer’s disease and related dementias than those receiving other types of osteoporosis medication.

The findings add to growing scientific interest in the relationship between bone health and brain health. However, researchers emphasize that the study does not establish that osteoporosis drugs directly prevent Alzheimer’s disease.

Study Examined More Than 121,000 Older Adults

The research involved 121,492 adults aged 60 and older in Hong Kong who had recently been diagnosed with osteoporosis or had experienced a serious fracture involving areas such as the hip, wrist, spine or upper arm.

Importantly, participants had not previously taken osteoporosis medication when they entered the study. Researchers then examined their subsequent medication use and compared dementia outcomes among different groups.

The study was published in the journal Alzheimer’s & Dementia.

The medications at the center of the research belong to a class known as nitrogen-containing bisphosphonates, or NBPs. These drugs are commonly prescribed to slow bone loss and reduce the risk of fractures among people with osteoporosis.

Examples include alendronate, ibandronate, risedronate and zoledronate.

Rather than examining whether these drugs directly treat Alzheimer’s disease, the researchers looked at whether their use was associated with different rates of dementia over time.

What Are Bisphosphonates?

Osteoporosis causes bones to become weaker and more vulnerable to fractures. The condition becomes increasingly common with age and can have serious consequences when an older person suffers a hip or other major fracture.

Bisphosphonates work by slowing the breakdown of bone tissue. They have been used for years as part of osteoporosis treatment and fracture prevention.

The possibility that these medications could also be connected to brain health has attracted attention because scientists are increasingly studying what researchers sometimes describe as the “bone-brain axis.”

The idea is that the skeleton and brain may influence each other through biological pathways involving hormones, inflammation, metabolism and other signaling mechanisms.

“Emerging evidence points to a bone-brain axis, suggesting a close link between bone and brain health,” study author Ching-Lung Cheung, an associate professor at the University of Hong Kong, said in comments reported by Fox News.

Previous research has also found associations between low bone mass, osteoporosis and a greater likelihood of developing dementia later in life.

The Findings Do Not Prove the Drugs Prevent Alzheimer’s

Despite the size of the study, researchers caution against interpreting the findings as evidence that bisphosphonates should be prescribed to prevent Alzheimer’s disease.

The study was observational, meaning researchers analyzed patterns in existing health and medication data rather than randomly assigning patients to receive a particular drug.

That distinction is important.

An association between medication use and a lower rate of dementia does not necessarily mean the medication itself caused the reduction. Other differences between people who received treatment and those who did not could have influenced the results.

The researchers also acknowledged several limitations.

For example, the study population consisted of Chinese adults, meaning it remains uncertain whether the findings would apply in exactly the same way to other populations.

Researchers also did not have baseline cognitive testing for all participants. As a result, some people could have had cognitive impairment before entering the study without it being fully captured in the analysis.

Other potentially important factors were also unavailable, including the severity of osteoporosis and fractures and participants’ use of over-the-counter calcium and vitamin D supplements.

Why Bone and Brain Health May Be Connected

The connection between osteoporosis and dementia is becoming an increasingly active area of research.

Both conditions become more common with aging, but scientists are investigating whether the relationship involves more than simply sharing age as a risk factor.

Inflammation, hormonal changes, blood vessel health and changes in cellular signaling could potentially influence both the skeleton and the brain.

Recent scientific reviews have also examined whether existing medications could be repurposed or studied for possible effects on dementia risk. However, evidence varies considerably between drug classes and individual medications, reinforcing the need for controlled clinical research.

Researchers are particularly interested in determining whether medications that influence bone metabolism might also affect biological processes involved in neurodegeneration.

At this stage, however, the mechanism remains uncertain.

More Research Is Needed

The study’s authors say the next major step is a clinical trial designed specifically to test whether bisphosphonate treatment can influence dementia risk.

A randomized clinical trial could help determine whether the relationship observed in the Hong Kong study is causal or whether other factors explain at least part of the association.

Researchers also want future studies to include more diverse populations and investigate whether the apparent relationship differs between men and women.

For now, the findings offer another reason scientists are looking beyond the brain itself when studying Alzheimer’s disease.

Alzheimer’s remains a complex condition influenced by numerous biological and environmental factors. There is currently no evidence from this study that people should take osteoporosis medication solely to reduce their risk of dementia.

Instead, the research highlights a potentially important connection between two major health concerns associated with aging: declining bone strength and cognitive health.

If future clinical trials confirm the findings, drugs already widely used to protect bones could eventually become part of a broader discussion about dementia prevention. Until then, researchers stress that the observed association is an important lead for further investigation rather than proof of an Alzheimer’s treatment.