Hyaluronic Acid: Much More Than Just Cosmetics

What is Hyaluronic Acid?

Hyaluronic acid (also known as hyaluronan) is a polysaccharide found in all vertebrates, including humans, throughout the body. It is a molecule that can consist of 250 to 50,000 disaccharide units and forms highly branched networks. This spatial structure and its negatively charged ions give hyaluronic acid its unique ability to bind large amounts of liquid. One gram of hyaluronic acid can bind up to six liters of water! This results in a highly viscous gel that serves as a lubricant and shock absorber for our joints and moisturizes our skin.

In our body, the total content of hyaluronic acid is about 15 grams. It is primarily found in connective tissue, the vitreous body of the eye, and articular cartilage, and is a central component of synovial fluid. Approximately 30 percent of our hyaluronic acid supply is nonspecifically metabolized and broken down each day, while the remaining 70 percent is systematically metabolized. Hyaluronic acid ingested through food remains in the body for a maximum of three days, requiring our body to continuously replenish it.

How Was Hyaluronic Acid Discovered?

The roots of hyaluronic acid date back to 1880. The French scientist Portes first noted that the mucin he studied in the vitreous body of the eye differed from that in the cornea and cartilage, naming it "hyalomucin". Mucins are components of the mucus in many organisms with important protective and structural properties.

It was not until 1934 that German scientists Meyer and Palmer managed to isolate a new molecule from the vitreous body of cattle. It contained a uronic acid and an amino sugar, prompting them to call the molecule hyaluronic acid—a combination of the terms "hyaloid" (vitreous body) and "uronic acid". Since the 1940s, the physicochemical properties of hyaluronic acid have been intensively studied, and its structure was ultimately elucidated by Meyer and Weissmann in 1954. The growing understanding of its role in our body has led to increasing interest in its production and use in products for various applications. Initially, the focus was on extraction from animal tissues. However, as the removal of impurities proved problematic, attention increasingly turned to the production of hyaluronic acid through bacterial fermentation and chemical synthesis. In the 1990s and 2000s, optimizing bacterial fermentation techniques became a priority to specifically produce molecules of defined sizes. Special attention was also paid to the exact metabolic mechanisms of hyaluronic acid and the identification of the enzymes involved. Today, hyaluronic acid is a popular ingredient in numerous medical, pharmaceutical, nutritional, and cosmetic applications. Therefore, it continues to be intensively researched to uncover synthesis and metabolic pathways, optimize its production, and improve its application.

How Is Hyaluronic Acid Formed in Our Body?

Three enzymes are responsible for the body's own synthesis of hyaluronic acid from glucose or fructose. This is unusual and exciting, considering that hyaluronan is a simply constructed compound consisting of only two molecules (we remember: one amino sugar and one uronic acid). Two of the enzymes synthesize hyaluronic acid with a molecular weight of > 2,000 kilodaltons, while the third generates compounds with a size of 100 to 1,000 kilodaltons. The balance between the synthesis and breakdown of hyaluronic acid plays an important regulatory role in our body and changes throughout life.

High vs. Low Molecular Hyaluronic Acid

Numerous studies have been conducted on hyaluronic acid, yet despite this intensive research, little is known about its exact biological properties depending on molecular weight. The vast majority of our body's hyaluronic acid is present in high molecular form with a size of > 500 kilodaltons. Our hyaluronic acid also falls into this high molecular range. Molecules with sizes of 10 to 500 kilodaltons are referred to as low molecular. Results from scientific studies indicate that particularly the structural properties seem to depend on molecular size. Regarding other parameters, high and low molecular hyaluronic acid did not significantly differ in their effects in many studies. Hyaluronic acid with particularly low molecular weight is mainly used in skin creams to fill and support the connective tissue between skin cells.

Hyaluronic Acid in the Joints

As you have already learned, hyaluronic acid is an important component of our joints, bones, teeth, and skin. Collagen is another central building block of connective tissue and, with its fibrous properties, belongs to the so-called structural proteins. It constitutes more than 30% of all connective tissue and is also present in cartilage, bones, and our skin. In total, we have more than 140 joints that can withstand loads of up to 1,500 kg. It is only through a finely coordinated interplay of bones, cartilage, muscles, tendons, and ligaments that we are able to move at all. Running, jumping, dancing—none of this would be possible without our joints. We often only realize how important our musculoskeletal system is when certain movements suddenly do not go as smoothly as we are used to. With regular physical activity and a balanced diet, we can actively maintain our mobility. Certain nutrients can also specifically support joint function.

A true joint is a movable connection between two bones, enveloped by a joint capsule made of supportive connective tissue. In the joint space, there is cartilage and synovial fluid. The latter serves as a lubricant for smooth movement, while the cartilage, due to its high pressure elasticity, takes on a shock-absorbing function. It consists of many individual cartilage cells and collagen fibers that form a dense and elastic network. The joint fluid supplies it with important nutrients since it is not directly connected to the bloodstream. The saying "Who rests, rusts" can be taken literally here, as every movement pumps nutrient-rich joint fluid into the joint space. This is necessary for specific cells to form and to some extent repair the cartilage.

As part of normal wear and tear in the joints, the thickness of the cartilage layer decreases. Initially, this does not lead to complaints, and most people do not even feel it. However, strong stresses, recurring injuries, metabolic diseases, and inflammations can cause premature wear of the joint cartilage. This results in osteoarthritis. In this case, not only does the cartilage thickness decrease, but the consistency of the synovial fluid also changes, and the cushioning effect gradually diminishes. Once the cartilage is worn down, it cannot be rebuilt, and the joint surfaces would rub against each other like sandpaper. Therefore, it is all the more important to prevent and slow down wear and to ensure the supply of nutrients to the joints. To support the normal function of your joints and counteract premature wear, we have developed our CartivoPro Capsules with hyaluronic acid, vitamin C, and copper for you.