A rigorous, long-term study of over 1,400 older women has definitively debunked concerns linking calcium supplementation to an increased risk of dementia. The findings, published by researchers at Edith Cowan University (ECU), provide strong reassurance to both patients and clinicians regarding the safety of calcium supplements for long-term use. This matters because millions of people, especially women over 70 (roughly 20% of this demographic experience osteoporosis), take calcium to prevent bone fractures, and previous observational studies had raised unsubstantiated fears about cognitive decline.
The Study Design and Key Results
The research was a post-hoc analysis from a five-year double-blind, placebo-controlled randomized clinical trial. Participants – 730 women receiving calcium supplements and 730 receiving a placebo – were followed for an additional 14.5 years. Crucially, even after accounting for diet, lifestyle, genetic factors, and dosage, no statistically significant link between calcium supplementation and dementia risk was found.
According to ECU PhD student Negar Ghasemifard, the results “provide reassurance to patients and clinicians regarding the safety of calcium supplements in the context of dementia risk for older women.” This is a critical point: the original concerns were largely based on weaker, observational data prone to confounding variables. The controlled nature of this trial significantly reduces that risk.
Why Observational Studies Can Be Misleading
Earlier research suggesting a link was “purely observational,” explained ECU Senior Research Fellow Dr. Marc Sim. This means scientists observed correlations without actively controlling variables, making it impossible to prove cause and effect. For example, people who take calcium supplements might also have other health habits (or conditions) that influence dementia risk.
This new study’s design—a randomized controlled trial with a long follow-up period—offers much more reliable data. It’s still epidemiology (study of populations), not direct intervention, but it’s stronger evidence than previous claims.
What This Means for Future Research
While the findings are encouraging, researchers emphasize the need for further investigation. Professor Simon Laws, Director of ECU’s Centre for Precision Health, notes that the study focused on older women, and the results may not generalize to men or younger individuals.
To confirm these findings definitively, future trials should:
- Include men and women starting supplementation at different ages.
- Combine calcium with vitamin D (often taken together).
- Prioritize brain health as a primary outcome measure.
Expert Confirmation
Dementia Australia Honorary Medical Advisor Professor Blossom Stephan confirms the importance of these findings. “Given calcium’s critical role in multiple physiological functions, including bone health, these results provide reassurance that long-term calcium supplementation did not increase dementia risk in older women.”
The takeaway is clear: based on this robust study, older women can continue taking calcium supplements to prevent osteoporosis without undue worry about cognitive decline. More research is needed, but the long-held myth linking calcium to dementia has been effectively debunked.
