The health of your bones and the health of your brain probably don’t seem too closely connected.
So the suggestion that low bone density could be linked to dementia may not make a lot of sense.
You may already be aware that as we age, our bone mineral density tends to decrease, which can lead to a higher risk of fractures and other health issues.
And also, as we age, our risk of experiencing age-related cognitive decline increases.
A new study published in the journal Neurology this week has opened the door to a deeper understanding of how these two conditions may be related.
The Rotterdam Study
The Rotterdam Study is a long-term, ongoing population-based cohort study that started in 1990 in Rotterdam, Netherlands. It aims to investigate the determinants of various age-related diseases, including cardiovascular, neurological, ophthalmological, endocrine, and psychiatric disorders, in an elderly population.
The study initially enrolled about 8,000 participants aged 55 years or older, with the primary goal of examining the risk factors and occurrence of atherosclerotic cardiovascular diseases, dementia, and other neurological conditions. Over time, the study has been expanded to include new participants and a broader range of age-related diseases.
The Rotterdam Study collects a wealth of data on its participants, including detailed medical histories, interviews, physical examinations, and biological samples. Researchers analyze these data to better understand the etiology, progression, and outcomes of various age-related diseases.
Low Mineral Density and Higher Dementia Risk
The Rotterdam study has resulted in over 1600 scientific publications and reports and has contributed significantly to our understanding of the risk factors, genetic influences, and other determinants of age-related conditions.
This newly published analysis looked at the bone mineral density data from 3,651 participants who were free of dementia in the early 2000s. As of January 1, 2020, 688 (18.8%) of those participants had developed dementia.
The researchers were then able to observe that the group of people with the lowest bone mineral density scores had the highest rates of dementia. People who had higher bone mineral density scores had lower rates of dementia.
Although it’s not a conclusive guarantee that people with low bone density will develop dementia, the findings indicate that people with low bone density are 12% more likely to develop dementia than people with normal or higher density.
Possible Mechanisms Linking Bone Health and Dementia
While the precise mechanisms connecting low bone mineral density and dementia are still being investigated, several explanations have been proposed.
Both low bone mineral density and dementia share common risk factors or underlying processes. For example, inflammation and oxidative stress have been implicated in both bone loss and neurodegeneration. Certain hormonal imbalances, such as reduced levels of estrogen in women, may also contribute to both osteoporosis and dementia.
A sedentary lifestyle has also been linked to a higher risk of osteoporosis and fractures, as well as cognitive decline. Exercise not only helps to maintain bone mass but also promotes the release of chemicals in the brain that support learning and memory.
Similarly, poor nutrition can negatively impact both bone health and cognitive function. A diet lacking in essential nutrients, such as calcium and vitamin D, can lead to a decrease in bone mineral density. At the same time, an inadequate intake of nutrients like omega-3 fatty acids and antioxidants can contribute to cognitive decline and dementia.
Low Bone Density as an Early Warning Sign
The insights of this new research suggest that low bone mineral density may serve as an early warning sign for dementia—like the canary in the coal mine.
For example, if a physician has a patient with low bone density, this may indicate a need to take additional steps to screen for cognitive decline and address shared risk factors such as poor nutrition and physical inactivity.
Further studies are needed to better understand the underlying mechanisms that connect low bone density and dementia risk.
This could lead to the development of new strategies to prevent or delay the onset of dementia by addressing bone health before cognitive decline gets too severe.