Osteoporosis is a sneaky disease that is often diagnosed too late and should be prevented already at early ages. Not everyone knows that our bones reach their maximum calcification level at 20. After then, a gradual but steady bone loss occurs all along our life. To avoid a high risk of fractures in older ages, it is imperative to keep appropriate calcium intake early in life and an active lifestyle at all ages. However, there is much more to know about this disease. In this article, I have summarized the main concepts you will need to familiarize yourself with to prevent (or manage) this common health condition.
Bone loss, or bone resorption, is the breaking down and reabsorption of bone tissue. It is a physiological process that occurs throughout life but becomes more pronounced with age.
Several factors can contribute to exacerbating bone loss, some of them are preventable, whereas others are not:
- Aging: Our bodies naturally produce less bone as we age, which can lead to bone loss.
- Hormonal changes: Changes in hormone levels, particularly in women after menopause, can cause bone loss. Estrogen helps to maintain bone density, and the decline in estrogen levels after menopause can lead to bone loss.
Although there is not much you can do to slow aging and the related hormonal changes, you can at least keep in mind that you can reduce the risk of osteoporosis already in early ages, a time when most people usually do not think about preventing this health condition.
- Lack of physical activity: A lack of physical activity can contribute to bone loss. Regular weight-bearing and strength-training exercises can help build and maintain bone density. Interestingly, a recent meta-analysis of the studies that investigated strength training, found that the lattes is also associated with a higher longevity, independently on whether one also performs aerobic training or not.
- Poor nutrition: A diet low in calcium and vitamin D can contribute to bone loss. Besides dairy products, other calcium-rich foods include kale, broccoli, fortified vegetarian milk, fortified tofu, and seeds. Some mineral waters can also represent a good source of calcium. As for vitamin D, consider eating more fatty fish (e.g., salmon) and sun exposure during summer and spring. Supplementation is also an option if your blood levels are constantly below the recommended ones. Check this post about osteoporosis and menopause that I published on my post some time ago to know more about these foods.
- Certain medications: Some medications, such as corticosteroids (used for inflammatory conditions) and anticonvulsants, can cause bone loss.
- Medical conditions: Certain medical conditions, such as hyperthyroidism and anorexia, can also cause bone loss. Consider discussing with your doctor the possibility of testing your bone health with a DEXA scan.
All in all, maintaining a healthy lifestyle and seeking medical attention are vital if you risk bone loss or osteoporosis.
Signs of Osteoporosis
Unfortunately, osteoporosis has usually no symptoms until a fracture occurs. Fractures occur more easily than expected among individuals who experienced significant bone loss. A fracture from a minor fall or from sneezing or coughing represent common warning that your bones deserve attention.
However, besides fractures, possible other signs include:
- Loss of height or a stooped posture
- Back pain caused by a fractured or collapsed vertebra
- A bone that breaks more easily than normal
If you are experiencing any of these signs or have a family history of osteoporosis, you should talk to your doctor. He or she can recommend lifestyle changes or medications to help prevent or treat osteoporosis.
Osteoporosis prevention: How to increase bone density
There are several things you can do to help prevent osteoporosis. As I wrote above, the earlier you start with these changes, the greater the chances to delay bone loss. Here are some useful suggestions:
- Get enough calcium and vitamin D: Calcium is essential for strong bones, and vitamin D helps your body absorb calcium. Good sources of calcium include dairy products, green leafy vegetables, and calcium-fortified foods and beverages. You can get vitamin D from sunlight, fatty fish, and fortified foods.
- Exercise regularly: Weight-bearing and strength-training exercises can help build and maintain bone density. Walking, jogging, dancing, and lifting weights are good choices.
- Don’t smoke and limit alcohol consumption: Smoking and excessive alcohol consumption are both enemies of your bones.
- Eat a balanced diet: A diet that includes a variety of fruits, vegetables, and protein can help support bone health.
- Consider taking a bone-building medication: If you are at high risk of osteoporosis or have already been diagnosed, your doctor may recommend a medication to help prevent or treat osteoporosis.
If you suspect you have osteoporosis or osteopenia (i.e., lower than normal bone mass or mineral density), you could consider monitoring parathyroid hormone levels in your blood. Parathyroid hormone (PTH) is a hormone produced by the parathyroid gland that helps regulate calcium and phosphorus levels in the body. It plays a vital role in bone metabolism, helping to maintain a balance between bone resorption and bone formation.
When calcium levels in the blood are low, PTH is released and stimulates the osteoclasts, cells that break down bone tissue, to increase bone resorption. This releases calcium and other minerals into the bloodstream, helping to raise calcium levels. At the same time, PTH also stimulates the production of a hormone called calcitriol, which is the active form of vitamin D. Calcitriol helps the body absorb calcium from the diet and increases the production of osteoblasts, which are cells that build bone tissue (see the last section of this article for more details about this).
By the above mechanisms, PTH helps to stimulate both bone resorption and bone formation, helping to maintain a balance between the two processes and supporting healthy bone density. However, excessive PTH production can lead to bone loss and increase the risk of osteoporosis. Maintaining a healthy balance of PTH and other hormones is essential to support healthy bone metabolism.
Many people use bisphosphonates to treat osteoporosis. Therapy by bisphosphonates, denosumab, hormone therapy, and selective estrogen receptor modulators (SERMs) inhibit osteoclasts, which are the cells responsible for breaking down and reabsorbing bone tissue.
However, recent studies suggest a role for bioactive peptides in bone health. The latter seem to exert a wide range of bioactivities. IRW, in particular, has attracted the interest of scientists. It is a tripeptide composed of three amino acids: isoleucine, arginine, and tryptophane derived from ovotransferrin, a glycoprotein from egg white albumen. This peptide was initially discovered because it can reduce systolic and diastolic BP in hypertensive laboratory animals. However, more recent research revealed that IRW can also act on Akt protein kinase B activation, an enzyme connected to bone formation via the proliferation, differentiation, and mineralization of bone cells.
It also activates insulin signaling pathways in osteoblasts. Therefore, IRW function depends on the insulin receptor, and IRW could activate the insulin receptor and, consequently, PI3K and Akt effects, which are related to bone formation. Activation of insulin signaling pathways in osteoblasts (i.e., cells that build bone tissue) can have several effects on bone metabolism:
- Increased bone formation: Insulin can stimulate the production of osteoblasts and increase bone formation.
- Increased bone density: By increasing bone formation, activating insulin signaling pathways in osteoblasts can help increase bone density.
- Decreased bone resorption: Insulin can also inhibit the activity of osteoclasts, cells that break down bone tissue, leading to a decrease in bone resorption.
Overall, activating insulin signaling pathways in osteoblasts can positively affect bone metabolism and help maintain or increase bone density.
Postmenopausal osteoporosis and male osteoporosis
Postmenopausal osteoporosis is a type of osteoporosis that occurs in women after menopause. The decline in estrogen levels which protect bone health during fertile ages, can lead to bone loss and increase the risk of osteoporosis after menopause.
It is more common in older women: The risk of osteoporosis increases with age, and postmenopausal osteoporosis is more common in women over 65.
It is often asymptomatic until a fracture occurs, usually in the spine, hip, and wrist.
Male osteoporosis is similar to postmenopausal osteoporosis in that weak, brittle bones and an increased risk of fractures characterize it. Various factors, including low testosterone levels, long-term use of corticosteroids, and certain medical conditions, can cause it.
However, there are some differences between the two:
- Male osteoporosis is less common than postmenopausal osteoporosis.
- Male osteoporosis tends to develop later in life than postmenopausal osteoporosis.
If you are experiencing symptoms of osteoporosis or are at risk of the condition, it is crucial to talk to your doctor. They can recommend lifestyle changes or medications to help prevent or treat osteoporosis.
The science behind bone health
Bone remodeling involves osteoclasts and osteoblasts. An unbalance between osteoblasts and osteoclasts characterizes osteoporosis.
Osteoclasts are large, multinucleated cells found in the bone tissue and are involved in the process of bone resorption, which is the breaking down of bone tissue.
Osteoblasts are cells that are responsible for building bone tissue. They are found in the bone tissue and are involved in bone formation, which is the building of new bone tissue.
Osteoblasts are formed from mesenchymal stem cells, which are cells that can differentiate into various types of cells, including osteoblasts. Osteoblasts are activated by hormones such as calcitriol, the active form of vitamin D, and growth factors such as bone morphogenetic proteins (BMPs). When activated, osteoblasts secrete proteins, such as collagen, that form the matrix of bone tissue. They also deposit minerals, such as calcium, onto the matrix to form the hard, mineralized bone tissue.
Osteoblasts play a vital role in maintaining bone homeostasis, helping to repair and regenerate bone tissue throughout life. However, an imbalance between bone resorption, the process of breaking down bone tissue, and bone formation can lead to osteoporosis, a condition in which bones become weak and brittle, increasing the risk of fractures. Maintaining a healthy balance of bone resorption and formation is essential to maintain strong, healthy bones.
Osteoclasts are formed from monocytes, a type of white blood cell. They are activated by hormones such as parathyroid hormone and cytokines, which are proteins that help regulate immune system function. When activated, osteoclasts secrete enzymes that dissolve the mineralized matrix of bone tissue and release the minerals, such as calcium, into the bloodstream.
While osteoclasts play a vital role in maintaining bone homeostasis, excessive bone resorption can lead to osteoporosis and increased fracture risk. Maintaining a healthy balance of bone resorption and formation is essential to maintain strong, healthy bones.
It is clear from this article that lifestyle factors are crucial to prevent this health condition, and a healthy lifestyle (as well as a calcium-rich diet) should be considered early in life. New preventive approaches, such as peptides, are coming up, but they cannot replace a healthy and active lifestyle. Prevention includes screening of bone mass and density. On this webpage you can see which individuals should be screened for osteoporosis by DXA. Finally, I would like to remark that men are not exempted from this health condition, although the osteoporosis narrative still focuses too often on women and menopause.