Low Bone Density May Increase Dementia Risk by 42%, According to New Research—Here’s What To Know

By Karla Walsh  Published on March 29, 2023 Reviewed by Dietitian Jessica Ball, M.S., RD

PHOTO: GETTY IMAGES

Your bones and brain seem like two fairly separate systems, right? The brain tells the muscles how to move the bones, true. But otherwise, when you look at neurons vs. osteoblasts, smarts vs. structure; these body parts don’t seem to have a whole lot in common.

But just as gut health can help (or hurt) mood, there are some surprisingly systemic relationships within our fascinating, complex bodies.

This week, we’re learning more about a potential association between brain health and bone health, and anyone who’s getting older (ahem, all of us!), might want to listen up. According to a new study published March 22, 2023 in Neurology, the medical journal of the American Academy of Neurology (AAN), people who have low density may be at 42% higher risk for developing dementia later in life (compared to their stronger-boned peers).

Ahead, learn more about how they came to this conclusion, then discover how to start bolstering your bone strength today to benefit your sharpness and skeleton all at once.

What This Bone Density Study Found

Study author Mohammad Arfan Ikram, MD, Ph.D., professor and head of neuro-epidemiologic research at the Erasmus University Medical Center in Rotterdam, Netherlands and his team of researchers tapped into data from the Rotterdam Study, a large bank of residents in the Netherlands who have signed on to take part in research.

The 3,651 participants they analyzed were 72 years old, on average, and did not have a dementia diagnosis at the outset of the study. Every 4 to 5 years, each person received a physical exam, which included X-rays to track bone density, an interview and a cognition test.

Over the next 11 years, Dr. Ikram and his team found that 688 individuals (19%) went on to develop dementia. Among the 1,211 people with the lowest total body bone density at the outset, 90 people developed dementia over the course of the following decade (about 7.4%). Among the 1,211 with the highest total body bone density, only 57 (about 4.7%) developed dementia during that same timespan.

After crunching all the numbers and adjusting for age, gender identity, medication use, education level and family history of dementia, this study found that people with the lowest total-body bone density were 42% more likely to develop dementia over the next 10 years compared to their neighbors with the strongest bones.

“Low bone density and dementia are two conditions that commonly affect older people simultaneously, especially as bone loss often increases due to physical inactivity and poor nutrition during dementia,” Dr. Ikram notes in an AAN press release. “However, little is known about bone loss that occurs in the period leading up to dementia. Our study found that bone loss indeed already occurs before dementia and thus is linked to a higher risk of dementia.”

While these results suggest that low bone density may precede cognitive decline, it’s important to note that both of these conditions always get more common with older age. The scientists admit that it’s too early to prove cause and effect, and more deeper-dives are required (involving a more racially- and age-diverse pool of participants).

For reference, osteoporosis affects about 20% of women and 5% of men over age 50, according to the National Institutes on Aging (NIA). As we reported about last fall, nearly 10% of all Americans over 65 have been diagnosed with dementia, and an additional 22% have signs of mild cognitive impairment.

“Previous research has found factors like diet and exercise may impact bones differently as well as the risk of dementia. Our research has found a link between bone loss and dementia, but further studies are needed to better understand this connection between bone density and memory loss,” Dr. Ikram admits in the press release. “It’s possible that bone loss may occur already in the earliest phases of dementia, years before any clinical symptoms manifest themselves. If that were the case, bone loss could be an indicator of risk for dementia and people with bone loss could be targeted for screening and improved care.”

The Bottom Line

This new dementia study found that those who have weaker bones appear to be at 42% higher risk for developing dementia later on in life. It’s too early to tell, though, if this is just a coincidence among these two common aging-related conditions or if it’s an actual connection.

Many of the risk factors for a decrease in brain power and bone strength overlap, so as we continue to learn more about the possible link, it certainly can’t hurt to integrate healthy habits that benefit our brain and bones all at once. Start today:

• Rack up enough physical activity, including bone-supporting resistance training
• Consume a nutritious, well-balanced diet, and keep bone-supporting calcium, vitamin D and protein intake top of mind (psst…we have a whole collection of healthy bone-supporting recipes!)
• Limit alcohol use, if you imbibe
• Don’t smoke (or talk to your healthcare team about help with quitting, if you do)
• Score 7 to 9 hours of sleep regularly
• Challenge the brain through puzzles, reading, music or other hobbies, or give the brain and the body a workout all at once through coordination-related activities like yoga, dancing or Tai Chi
• Seek treatment for symptoms of depression, if present
• Try to build in ways to stay socially connected.