Osteoporosis: HA’s role in a “silent pandemic”.
During the year 2020, the COVID-19 pandemic was center stage in everyone’s awareness. But there is another “silent pandemic” that has been occurring for years that affects the lives of millions of people, especially women. Osteoporosis, the loss of structural stability of the inner core of bones, has been called the world’s “silent pandemic” because of the disease’s negative quality of life, medical, and economic consequences. In an earlier section, we talked about osteoarthritis, an age- and immune-dependent joint disease. Osteoarthritis is a distinct disease from osteoporosis.
Every woman—and some men—should be worried about osteoporosis. Ten percent of people in the world and 30% of post-menopausal women suffer from osteoporosis. Osteoporosis is the main cause of bone fractures in elderly men and women (Bellar, et al., 2019). In the United States, 300,000 people aged 65 years old or older will experience hip fracture due to osteoporosis. Three-quarters of these fractures will occur in women because women more often have osteoporosis than do men.20 Hip fracture is a major cause of death among the elderly. Thirty percent of elderly people with hip fracture will die within a year of fracturing their hip (Brauer, et al., 2009; Amin, et al., 2014).
Each person’s risk of developing osteoporosis is determined mostly by genetics, which is reflected in our family histories. However, risk of osteoporosis can be influenced by lifestyle choices. Osteoporosis risk is reduced by eating healthy, getting enough calcium (Dairy products like ice cream—yum—or calcium supplements), taking vitamin D supplements, and getting lots of weight-bearing exercise (gardening and walking are GREAT exercise). Osteoporosis risk is increased by lifestyle choices that weaken bones. These include drinking excessive alcohol, smoking, having an eating disorder, and taking illicit steroid drugs without physician supervision. Long-term exposure to high doses of prescription steroid drugs, such as prednisone, also can lead to osteoporosis, which is why it is so important to take all steroid drugs according to a doctor’s prescription.
The way that hip bones are structured make hips highly susceptible to breaks in the elderly. The femoral head (the part of the hip bone that projects from the femur leg bone into the hip joint) is joined to the femur leg bone by a narrow neck. That narrow neck must be very strong to withstand the stress placed on it. Healthy internal bone structure is essential to that strength.
In advanced osteoporosis, the internal structure of bone becomes damaged, which severely weakens bone (see the pits and holes in the femur on the right in the hip joint image). Any weakened bone can break but hip fractures among the elderly are the most concerning because hip fractures often lead to disability, loss of independence, and even death.
Most hip fractures occur as the result of falls 21but hip bones can become so weakened by osteoporosis that, even in the absence of a fall or other trauma, the femoral neck can spontaneously fracture and the femoral head will break away from the main body of the femur leg bone. 22So, if your grandma says, “My leg just gave out and I fell.” and is later found to have broken her hip, she might be telling the truth. Start thinking about bone strength while you are young, because it is important to eat healthy, get plenty of exercise, and maintain calcium and vitamin D intake so this does not happen to you!
21Centers for Disease Control and Prevention. https://bit.ly/2XVNh6R.
22Mayo Clinic. https://mayocl.in/2YoeTR3.
Healthy hip bone (left). Weakened hip bone due to osteoporosis (right).
(Purchased image used under an end user license agreement. Some annotations were
added by the authors.)
Despite clinical evidence from dentistry and basic science evidence that HA helps to rebuild bone, very little basic science or clinical research has been conducted to investigate HA in preventing or treating osteoporosis. A search of ClinicalTrials.gov using the keywords “hyaluronan” (or the closely-related “hyaluronic acid” or “sodium hyaluronate”) and “osteoporosis” returned no current or former clinical trials investigating HA in osteoporosis. The lack of clinical trials combined with the paucity of basic science research reports about HA in osteoporosis suggests that the research and clinical communities are just beginning to comprehend the importance of HA in osteoporosis23.
Thirty-six percent of Americans use integrative, alternative, and complementary medicine services. There is an oft-repeated pattern when integrative medicine treatments enter mainstream medicine: The positive benefits from what once were considered fringe medicine treatments become more widely known to clinical practitioners in their daily practices, possibly because their patients begin to ask their doctors about what they’ve heard or read about an integrative medicine technique. Then, as case study reports of the benefits of these integrative medicine practices start to enter the peer-reviewed clinical literature, additional practitioners as well as clinical researchers become aware of the techniques. Next, clinical researchers begin to design and conduct studies to determine if the reported benefits of the integrative medicine treatment are real. The awareness, validation, and acceptance of acupuncture24 as a valuable and effective alternative well-being and curative therapy is an excellent example of this process (VanderPloeg & Yi, 2009; Mao & Kapur, 2010). This probably is the status of the clinical awareness and application of HA in preventing and treating osteoporosis.
23ClinicalTrials.gov. Retrieved June 13, 2020. https://bit.ly/3hOD0B.
24Johns Hopkins Medicine. https://bit.ly/2Y6zsCB.
Examples of basic science research using HA osteoporosis include:
- In rats with artificially induced osteoporosis, oral HA decreased bone turnover leading to increased bone density (Ma, et al, 2013).
- In cultured cells, low molecular weight HA has been observed to reduce cell processes that contribute to osteoporosis, which suggests that oral HA might help to prevent and treat osteoporosis (Lee, et al, 2014).
- Some basic science studies investigate using HA’s affinity for bone to target anti-osteoporosis drugs to bone. The antiosteoporosis drug, bisphosphonate, has been delivered to bone by using the ability of HA to home in on and target bone cells (Hulsart-Billström, et al., 2013; Kootala, et al, 2015).
These studies are all conducted in animals or cultured cells and are too preliminary to predict whether oral HA is beneficial to prevent or cure human osteoporosis. However, the benefits of HA for osteoporosis suggested by these articles combined with the proven clinical benefits of HA for improving bone demonstrated in dental clinical studies provide an intriguing suggestion that adding HA to a healthy diet and exercise might help to prevent or treat osteoporosis.
In the next section, we will switch to a different organ system, the immune system. We have already discussed HA in osteoarthritis, which is partially an immune system-mediated disease. However, now it is time to delve deeply into the role of HA in the immune system. This is going to be an interesting and informative section.