Joints are amazing biological mechanisms!
Did you know that there are 208 bones and 360 joints in the human body? Somehow, we need to keep them all strong and healthy. Repairing all these bones and joints would be a major overhaul.
Joints perform work to transform energy into movement. 11They accomplish this by generating power and torque. (Hmmm, sounds like an automobile engine.) Joints move. They twist. They allow us to move our fingers to type on a keyboard, like I am doing while I type this book. Joints let us dance for joy when something wonderful happens. Joints even distinguish humans and primates from other animals. Without our thumbs, which have 2 joints, and our opposing forefingers, which have 3 joints, we could not pick up coins or write with a pen.
However, because they move and twist, joints are susceptible to mechanical damage and are convenient targets for our immune systems in immunity disorders like arthritis12. We take our joints for granted until our knees hurt when we walk upstairs or our hips hurt when we try to bend over to pick up something. Modern medicine has expended considerable energy to solve problems with joints.
In certain circumstances when the immune system and joints meet, bad things might happen (Bowman, et al., 2018). Because of the wear and tear experienced by joints, sometimes body molecules from joints that should be hidden from the immune system become exposed to the immune system. This is a problem because body molecules that should be hidden from the immune system will be viewed as intruders by the immune system. This will activate the non-specific innate immune response. (We will talk in detail about the innate and adaptive immune systems in the section, “HA plays surprising—sometimes contradictory—roles in the immune system.”) There also are cases when these previously hidden body molecules resemble intruder molecules to which the adaptive immune system has already responded. The adaptive immune system cannot distinguish between highly similar molecules that originate from an invading pathogen, versus molecules that originate from a previously hidden body site. When either of these events occur, the immune system begins to attack. This can happen anywhere in the body, but, because the previously hidden body molecules are concentrated in joints, the inappropriate immune response begins to damage the joints.
When the immune system attacks joints, various forms of arthritis can occur. There are over 100 different kinds of arthritis and arthritis-related conditions, but a common form of arthritis related to aging is “osteoarthritis”. Get ready, because, as we age, it is likely that all of us will experience osteoarthritic joints to some degree. People, like performance athletes, who place stress on their 37 joints are also at risk of osteoarthritis.13Luckily, oral Hyaluronic Acid has been shown to prevent arthritis in some, but not all, people and to improve arthritis symptoms in some other people. Osteoarthritis
Later in the “HA plays surprising—sometimes contradictory— roles in the immune system” section, we will talk about how HA binds to the surface of immune cells to modulate their function. One way that HA can modulate immune cell function is to reduce cellular processes that lead to excessive inflammation (Asari, et al., 2010).
HA has become a valuable tool for physicians to use to protect and rescue our joints from damage (Bowman, et al., 2018). Do you remember earlier, in the “Hyaluronan is an essential bodily molecule” section, we discussed how having a substance used in human clinical studies is a good indicator that a substance can benefit human health? On ClinicalTrials.gov, clinical studies using HA (or the closely related hyaluronic acid or sodium hyaluronate) in joints were retrieved by using the keywords “joint” and “hyaluronan” in a search. Two hundred and thirty current or former clinical studies were found that focused on the clinical application of HA as a therapy for preventing or fixing joint damage. 15Most peer-reviewed medical literature and practice focus on sterile HA that is injected into joints by physicians (Hermans, et al., 2019), either alone or mixed with other substances. 16Injections have been shown in many clinical studies to be effective treatment for joint pain caused by arthritis and injury (Bowman, et al., 2018), but injections are painful, invasive, and expensive. Also, injections are intended to fix problems after they occur but not prevent problems from occurring in the first place.
15https://bit.ly/2YFMTbF. Retrieved June 13, 2020
16HA-TOPSHELF is an oral, over the counter HA supplement. Do not use the product for injections.
Injections always should be performed only by a qualified, licensed physician.
Earlier in this book, we discussed the importance of preventative medicine. It would be much better for our joints if we prevented joint damage before it occurred. We can do that by taking care of our joints to prevent injury. We also can eat a diet intended to maintain joint health. Oral HA dietary supplements have been shown in peer-reviewed clinical studies to improve joint health and to help joints heal after damage (Moriña, et al., 2018; Tashiro, et al., 2012). Taking oral HA is less invasive, less expensive, and more convenient for patients. As osteoarthritis progresses, both the concentration and the molecular weight of HA remaining in arthritic joints decrease (Maheu, et al, 2016). Taking a high molecular weight HA supplement might be important to replace lost high molecular HA. It is unlikely that taking oral HA alone will prevent or solve all joint problems. However, oral HA is an important preventative health measure that is easy and convenient to apply to prolong the health of joints and to optimize other joint treatments, including exercise, surgery, and injections. That is a pretty good trade-off since an ounce of prevention is always better than an expensive, painful cure.
Oral HA has been shown to have many benefits for arthritis (Oe, et al., 2017; Sanchez, et al, 2014; Yoshimura, et al., 2012). One of the main difficulties that people with arthritis experience is chronic, sometimes debilitating, pain. A clinical study was conducted to observe whether oral high molecular weight HA relieved pain in people who had degenerative joint disease and other rheumatic conditions, including arthritis. People in the clinical study who took oral high molecular weight HA experienced more pain relief compared to people who took a placebo supplement. The extra pain relief lasted for two weeks. After two weeks, people in the treatment group started to become more active because they were pain-free. Physical activity is an important preventative health measure. The added activity caused their pain to increase again, albeit not to the level that they had experienced prior to oral HA treatment. This study indicates that oral HA, especially high molecular weight HA, relieves chronic pain and reduces use of pain medication (Jensen, et al., 2015). Less pain can lead to downstream benefits, including increased physical activity. Interestingly, people who previously had taken oral HA were excluded from this clinical study because of the known pain-relieving effects of oral HA, which would have complicated analysis of the data.
A similar clinical study demonstrated that oral HA of unknown molecular weight, when combined with other substances not only relieved pain but also improved the quality of life for people with knee osteoarthritis (Kalman, et al., 2008; Maia, et al. 2019). A clinical study demonstrated that the combination of oral high molecular weight HA and therapeutic exercise was particularly effective in alleviating symptoms of osteoarthritis (Tashiro, et al., 2012). Importantly, studies have shown that the pain-relieving effects of high molecular weight HA are long-lived. Forty months after injection of HA into knees, more patients who received an HA injection in their knees reported pain relief compared to patients who received a placebo injection in their knees (Maheu, et al, 2016).
Knees and joints also contain a tissue called cartilage. In osteoarthritis, the immune system often damages cartilage (Kaux, et al., 2016). High molecular weight HA appears to protect cartilage cells from damage by modulating both immune cell function to reduce attacks on cartilage and by protecting cartilage cells from dying due to damage (Chiou, et al., 2018; Honda, et al., 2017; Kaux, et al., 2016). So, HA functions in many ways to keep joints healthy and pain free.
In the next sections, we will tell you a case study of how HA reduced joint pain and stiffness. Then, in “No bones about it: HA is important”, we will discuss how HA strengthens bones.