Bone Loss Linked to Brain Issues in New Study

The health of your bones may be connected to the health of your brain.

New research based on more than 700 older adults suggests that those with lower bone density were more likely to experience faster deterioration of cognitive function as they aged as well as accelerated age-related injury to brain tissue.

“A scan you already had may be telling you more than it was ordered to,” says lead study author Sara Momtazmanesh, MD, a postdoctoral research fellow in the department of radiology and radiological sciences at Johns Hopkins University in Baltimore.

“Bone density from a routine chest CT tracked with how people’s brains changed over the following years, suggesting bone and brain age together rather than separately,” she adds.

Bone Loss May Indicate Brain Trouble Ahead

“What was missing was whether bone density measured today tells you anything about what happens next,” says Dr. Momtazmanesh. “To our knowledge, this is the first study to follow people over time and link a baseline bone measurement to the actual rate of change in white matter structure and in cognition.”

The research team also looked at the microscopic organization of the brain’s white matter, which can reveal damage earlier compared with visible lesions.

For the study, published this week in Radiology (the journal of the Radiological Society of North America), the authors analyzed bone density data derived from the noncontrast chest CT scans of 715 adults, ranging in age from 65 to 75 (397 men and 318 women).

The MRIs revealed associations of low bone density with microstructural changes in areas of the brain known to be vulnerable to vascular and metabolic injury. These tiny changes appeared without a change in total lesion volume (visible abnormal tissue in the brain) — indicating that subtle tissue disruption existed even before visible damage.

Momtazmanesh highlights that participants in the lowest quarter of bone density accumulated white matter lesions in the corpus callosum (a thick band of nerve fibers in the center of the brain) about 15 percent faster per year than those in the highest quarter.

Less Bone Density Associated With Lower Cognitive Performance

The cognitive testing for the study assessed overall thinking ability, covering factors such as memory, language, attention, and the speed at which someone can process information under time pressure.

Those in the lowest quarter of bone density were linked to a 0.3 percent faster decline in their global cognitive score compared with those in the highest quarter bone density group, according to Momtazmanesh.

Diabetes Appears to Especially Heighten Risk

The connection was strongest for people with diabetes, according to Deborah Kado, MD, professor of medicine specializing in geriatrics at Stanford University and co-director of the Stanford Longevity Center in California.

“I would probably focus on highlighting the importance of diabetes patients optimizing their healthcare by making sure they are screened for osteoporosis and talk to their doctor about any cognitive concerns,” says Dr. Kado, who was not involved in the research.

While the study did not explore the cause of this association, Kado suggests that it may simply be two signs of deterioration that are occurring in parallel: “As people age, they tend to lose the calcium in their bones and gain calcium in their arteries, including in the small arteries that are in our brain,” she says.

Bone density testing may help flag those at risk for simultaneous skeletal and neurologic decline, allowing earlier screening and risk-factor management, she says.

The Study Has Some Limitations

Kado praises the new research for including a large, diverse multi-ethnic population and using state-of-the-art measures, but she views the magnitude of the differences measured as very small, bringing into question their clinical relevance.

Also, because the study is observational, it could not demonstrate whether bone loss causes brain change, but simply that there appears to be a link.

Momtazmanesh says that she’d be curious to see future research on the impact of osteoporosis medications on brain changes that occur with aging.

There Are Ways to Keep Bones and Brain in Better Shape

There are likely many shared risk factors for different diseases that might not seem related, such as osteoporosis and dementia, according to Kado.

That suggests that taking steps toward adopting healthy lifestyle behaviors might decrease the risk of multiple diseases at once.

These measures that may simultaneously help bone and brain health include:

• Following a diet of minimally processed foods
• Getting regular physical activity, including weight-bearing resistance training
• Not smoking
• Keeping alcohol consumption to a minimum
• Checking vitamin D levels with a healthcare provider and taking supplementation if indicated (Vitamin D helps the body absorb calcium. Vitamin D also plays an important role in brain health and cognitive function.)

  [5]

  [6]

• Keeping diabetes and blood pressure well managed to protect blood vessels in both the bones and the brain

“Anyone with risk factors should talk with their doctor about formal bone density testing, since low bone density causes no symptoms until something breaks,” says Momtazmanesh.

If you’ve had a chest CT scan — for a lung cancer screening, calcium scoring, nodule follow-up, or other reason — your physicians may already have useful information about your bone density.

“These scans could provide an opportunistic measurement of bone density from the spine that is associated with a loss of cognitive function,” says Momtazmanesh.