Strong bones are important for healthspan and lifespan, reducing frailty and fracture risk as we age. Yet conditions characterized by low bone mass, namely osteoporosis and osteopenia, affect many people—and not just women. According to Healthy People 2030, it is estimated that 50 million people aged 50 or older have osteoporosis, 2 million being men. In addition, 43 million people, including 16 million men, have low bone mineral density which puts them at a greater risk for osteopenia. [1]
Let’s address the role of bone mineral density for health, its use as an indicator for healthful aging, how to understand your risk for low bone mass, and tips to build bone strength.
Key takeaways:
- Bone mineral density (BMD) is a measurement of the mineral content in bones, including calcium and phosphorus.
- A higher BMD is indicative of stronger bones and a lower BMD is associated with weaker bones.
- Peak bone mass occurs around age 30, so bone building is particularly important in your earlier years to ensure optimal stores to draw from as bone growth continues through adulthood.
- Lifestyle, nutrition, and physical activity all play important roles in supporting bone strength throughout the lifecycle.
- InsideTracker’s Bone Mineral Density genetic insight shows your genetic potential for having higher bone mineral density.
What is bone mineral density?
Bone mineral density (BMD) is a measurement of the mineral content in bones, including calcium and phosphorus. Measuring bone mineral density helps determine bone strength, with a higher BMD being indicative of stronger bones, and a lower BMD being associated with weaker bones, osteoporosis, and increased risk of falls and fractures.
Low BMD contributes to injury and mortality
Falls come with a number of negative health outcomes, especially as we age. According to the Centers for Disease Control (CDC) one out of every five falls in older adults results in injury and out of about 36 million falls reported by older adults each year, at least 32,000 of them result in death. [2]
How is BMD measured?
Bone mineral density is measured using a DEXA scan or Dual energy x-ray absorptiometry, usually in the hip and the spine. The results of a DEXA scan can help predict and determine the risk for bone loss and hip fractures.
T-scores are also used to determine bone health and strength based on data from DEXA scans. A T-score is determined by taking the individual BMD and the mean BMD in young females, aged 20-29 years old, divided by the standard deviation of the reference population.
The ranges for bone mineral density as defined by the World Health Organization in T-scores are: [3]
- Normal: T-score of -1.0 and above
- Low bone mass (osteopenia): T-score between -1 and -2.5
- Osteoporosis: T-score at or below -2.5
- Severe or established osteoporosis: T-score at or below -2.5 with fractures
How bone mineral density changes as you age
The activity of bone building in the body happens when we are younger, through around age 30. After age 30, when we hit peak bone mass, bone degradation begins to overtake bone formation with a process called bone resorption. Bone resorption occurs when bones are broken down to release minerals, such as calcium and phosphorus, for use in other physiological processes like muscle contraction and nerve conduction. Bone resorption is normal, but it becomes an issue when it happens at a higher rate than bone formation, especially for individuals with low peak bone mass.
While bone health is crucial for everyone, it's particularly important for women to support healthy bones as they enter perimenopause. As perimenopause begins, hormone levels, such as estradiol levels, begin to fluctuate and then decline. This change in estradiol levels leads to an increased risk of osteoporosis.
Factors that influence BMD
When it comes to bone health and strength, a number of factors can impact us such as lifestyle, environment, and genetics. These include:
- Lifestyle: According to the National Osteoporosis Foundation, lifestyle choices play a notable role in achieving optimal peak mass; these health habits can impact 20-40% of peak bone mass in adults. [4] If lifestyle choices around physical activity and nutrition are poor in early adulthood, peak bone mass can be compromised.
- Aging: As the aging process occurs, there is an increase in bone resorption paired with a decrease in bone formation. This leads to a decline in BMD in both men and women, with menopausal women more significantly impacted due to the decline in estrogen associated with menopause. [5]
- Nutrition: Certain nutrients help support bone growth throughout the lifespan. Calcium, vitamin D, protein, and potassium, among other vitamins and minerals, are critical to bone formation. [6,7] While it’s preferable to obtain these nutrients from your diet, sometimes supplementation—particularly of calcium and vitamin D—are necessary for bone health and to reduce fracture risk.
- Physical activity: Weight-bearing activities, including resistance training and weight-bearing aerobic exercise like walking, stimulate not only muscle growth, but also bone growth. When stress is placed on the bones during weight bearing exercise, it promotes the production of new bone cells. Additionally, strength and resistance training can support areas more susceptible to fractures, including the hips, spine, and wrists. [8]
- Genetics: Bone health and strength is impacted by nutrition, lifestyle, and other environmental factors, but some of the risk of low BMD lies in our genetic profile. [9] This video explains how:
How does DNA contribute to BMD?
When it comes to the relationship between DNA and BMD, research suggests that genetics may account for about 50-85% of our skeletal health. [9] The InsideTracker BMD genetic score is composed of gene variants that influence bone qualities such as porosity, strength, and mineralization. [10]
Knowing what your DNA says about your potential for high bone mineral density can provide empowering insight, and lead to better lifestyle choices.
Who is at risk for low BMD?
Low bone mineral density can impact a wide variety of individuals, so knowing the risk factors of low BMD can help tailor nutrition and lifestyle choices to support strong bones. There are both modifiable and non-modifiable risk factors when it comes to bone health—these include but are not limited to a family history of osteoporosis, smoking, alcohol consumptions, poor diet, and low levels of physical activity. [11]
Fortunately, there are blood biomarkers tested with InsideTracker that can help you determine a potential risk for low BMD:
- Vitamin D: A nutrient that aids in calcium absorption from the digestive system; long-term low intake can lead to the demineralization of bones.
- Calcium: A key mineral used in bone-formation, which provides the skeleton with strength and structure.
- Estrogen: A hormone critical to bone metabolism, promoting the activity of the cells that make new bones, called osteoclasts.
- TSH: A hormone that plays a role in bone metabolism and homeostasis; unoptimized levels may indicate an increased risk for low BMD.
Benefits of optimizing BMD
A decline of bone mineral density with age is inevitable, further emphasizing the importance of building a strong bone foundation and optimizing peak bone mass in your early years. This allows the body to have sufficient stores to draw from as you age.
Prioritizing bone health and building bone mass may also decrease the risk of falls and fractures, as well as lower the severity of injury and outcomes from those falls and fractures should they occur. This enables greater freedom and the ability to continue both daily and recreational activities through the lifespan.
Tips to improve bone health
So how do you work toward building up your bone strength? Here are some science-backed ways to help you get started:
- Ensure proper nutrition. A number of dietary factors can be modified to support bone growth and strength. You'll want to eat a variety of foods, but in particular, aim to incorporate foods that contain calcium and vitamin D, like dairy products (or fortified dairy alternatives), dark leafy greens, and oily fish like salmon or tuna. Protein found in foods like eggs, fish, beef, poultry, lentils, edamame, and tofu is also critical to bone health as it's broken down into amino acids, which promote muscle repair. Lastly, consider consuming caffeine and alcohol in moderation as both can reduce calcium absorption.
- Engage in regular weight-bearing exercise, including both aerobic and strength training in your routine. Always consult your healthcare provider before starting any new exercise routine.
- Maintain a healthy body weight as a low body weight is associated with low bone mass.
- Understand your genetic impact by combining blood + DNA. InsideTracker’s Bone Mineral Density genetic insight shows your genetic potential for having higher bone mineral density. And blood biomarkers including vitamin D, calcium, TSH, and estradiol in women can be taken with your genetic score to determine how your lifestyle choices may be modifying your genetic predisposition.
References:
- https://health.gov/healthypeople/about/workgroups/osteoporosis-workgroup#:~:text=In%20the%20United%20States%2C%20an,at%20increased%20risk%20for%20osteoporosis.
- https://www.cdc.gov/injury/features/older-adult-falls/index.html#:~:text=One%20out%20of%20every%20five,falling%E2%80%94usually%20by%20falling%20sideways.
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5335887/#:~:text=As%20defined%20by%20the%20World,%E2%88%921%20and%20%E2%88%922.5%20SD.
- https://pubmed.ncbi.nlm.nih.gov/26856587
- https://pubmed.ncbi.nlm.nih.gov/22870496
- https://www.tandfonline.com/doi/full/10.1080/10408390500466174
- https://pubmed.ncbi.nlm.nih.gov/26510847
- https://pubmed.ncbi.nlm.nih.gov/10780864/
- https://pubmed.ncbi.nlm.nih.gov/30377780
- https://pubmed.ncbi.nlm.nih.gov/30598549/
- https://pubmed.ncbi.nlm.nih.gov/30464484
