Introduction
When most people think of bone, they think of the long bones of body, such as those of the arm or leg. However, bone is a highly complex tissue that functions to make up the over 200 individual bones of the skeletal system. In fact, there exist four distinct types of bones including: long bones, such as the bones of the arm and leg, that provide leverage to facilitate movement; short bones, that facilitate movement and strength in complex joints such as the wrist and ankle; flat bones, such as the skull, sternum, ribs, and hip—considered the armor of the body; and irregular bones, such as facial bones and vertebrae, that are neither long, short, nor flat.
Bone is a rigid body tissue that consists of cells that are embedded within a hard intercellular material. Over time, bone mineral density and content can decrease, and this leads to osteopenia and eventually, osteoporosis. With advanced osteoporosis, there is a heightened risk for fracture, as bone becomes weak. Lifestyle factors such as exercise and nutritional interventions can help to develop and maintain bone health throughout the lifespan.
Bone is comprised of two main components. These include collagen and calcium phosphate. Collagen is a fibrous protein which provides flexibility to the bone, so that it can resist fracture. Calcium phosphate is a mineral that makes bones hard, rigid, and strong—again, capable of resisting fracture. At the microscopic level, bone consists of four cell types including osteoblasts, osteocytes, osteoclasts, and undifferentiated bone mesenchymal stem cells.
Bone has several different functions. It provides structural support for the mechanical action (movement) of soft tissues including the skeletal muscle and lungs. It provides protection to internal organs and tissues. For example, the skull provides protection for the brain, while the sternum provides protection for the heart and lungs. Bone also serves as a mineral reservoir (for calcium and phosphate), and in this way it helps to regulate the amount of these minerals in the circulation. Within the yellow marrow adipose cells, lipids are stored. Within the red marrow, blood cells are produced, including platelets, white cells, and red cells.
The majority of bone mass is developed early in life, prior to age 25, and bone is constantly changing, with new bone being made and old bone being broken down. The question of many is twofold: 1) how can I fully develop bone so that levels are heightened early in life and 2) what can I do to maintain bone health with aging. The text below addresses these questions.
Factors that Impact Bone
As bone density and strength varies across individuals, it is important to understand what contributes to these differences. First, the age of the individual greatly impacts bone health, as bones become thinner and weaker as we age. Race and family history also have an impact, with the greatest risk of osteoporosis for those who are White and Asian, as well as for those with a family history of bone weakness. Women have a higher risk of osteoporosis than men, mainly due to having less bone tissue—possibly related to the type and quantity of physical activity done during the early years of life, as well as differences in body size and hormone levels. We know there is an increased risk of osteoporosis for those who are very thin (with a body mass index of 19 kg/m2or less) due to having less bone mass to sustain function with aging. From a lifestyle perspective, we know that tobacco and alcohol use contributes to weaker bones and the increased risk of osteoporosis. Nutritional intake plays an important role, with a diet low in calcium and vitamin D contributing to diminished bone density, early bone loss, and an increased risk of fracture. Finally and perhaps most importantly from a lifestyle perspective, physical activity and structured exercise is crucial, as we know that people who are physically inactive have a higher risk of osteoporosis than do their more-active counterparts.
Exercise
As stated above, regular and strenuous exercise is vitally important if the goal is to develop and maintain bone mass and strength. Weight-bearing exercise is required—which may include both cardiovascular and strength training. From a cardiovascular point of view, exercise should include impact activities such as running, stepping, climbing, and playing sports such as tennis and basketball. While activities involving running and stepping will be helpful, heavy resistance exercise may be the best approach. This includes strength training exercise and should be done with heavy loads and using the long bones of the body. This would include exercises such as squats, deadlifts, standing press, and bench press with free weight, body weight, or machines. While balance exercise will not necessarily help to build bone, it may help to prevent falls, which will reduce the risk of fractures—the ultimate goal.
Nutritional Intake
Multiple factors are at play when it comes to nutritional intake. It is important to have an adequate intake of calories in order to maintain muscle mass. It is also important to have a regular intake of calcium and vitamin D (at the RDA or higher), in addition to quality sources of protein, to help develop and maintain bone. Emerging data indicate that the intake of certain vitamins and minerals is important—including magnesium, potassium, phosphorus, zinc, vitamin C, vitamin K, B vitamins, carotenoids, and phytochemicals. While the above should ideally be consumed through a variety of whole foods, doing so may prove difficult—in particular at the dosages needed. In such situations, it may be necessary to resort to the use of dietary supplementation.
Dietary Supplementation
Dietary supplements can help to fill in the gaps that may be present when attempting to consume all nutrients through whole food. They are a convenient, and usually economical, source of nutrients. Protein powders can be used as a readily-available and low fat source of high-quality protein. Calcium is important and possibly the most widely-utilized dietary supplement for purposes of bone health. Other vitamin supplements such as vitamin D, vitamin K, vitamin C, and B vitamins are commonplace and may support bone health. Emerging data indicate that pre and pro-biotics can influence the microbiome, which can have an impact on bone health. As with all supplements, it is important to select high quality products, with high absorption characteristics, at the correct dosage. This will ensure that the correct amount of nutrients are available to support the desired outcome.
Conclusion
Bone is an important tissue that is constantly turning over, with a noted overall decrease in bone density with aging. A variety of factors can influence bone growth, maintenance, and loss over time—some of which we have no control over but others which we can regulate through lifestyle interventions. Factors such as exercise, nutritional intake, and the use of dietary supplements are highly influential and can have a profound impact on bone health. Regular, weight bearing exercise is of utmost importance, ideally including heavy resistance training. Whole food nutrition, inclusive of high-quality protein and a variety of vegetables and fruits (to provide vitamins, minerals, and phytochemicals) should be a focus for enhancing bone health. Finally, select dietary supplements can complement a high quality, whole food diet and should be considered by those who desire optimal health through nutrient ingestion.
Disclaimer
The material presented on these slides is for general information purposes only. The information is not intended to provide medical advice but rather to provide individuals with information to better understand the value of lifestyle factors to support bone health. Individuals should consult with their healthcare provider prior to beginning any new exercise, dietary or supplementation program. No liability is assumed by CalerieHealth.
