Hyaluronic acid, also known as hyaluronan or hyaluronate, is a substance found in almost every cell of the human body. Its primary functions include lubrication, structural support, and water retention. In addition to its common cosmetic applications, it plays a crucial role in reducing friction within joints to facilitate smooth movement, and it is an essential component for maintaining lubrication and preventing dryness in the eyes.
What is hyaluronic acid?
Hyaluronic acid (also known as hyaluronan) is widely present in connective tissues, epithelial tissues, and neural tissues. Particularly in the skin, hyaluronic acid constitutes about half of the body’s total content. Additionally, it is found in high concentrations in joints, eye sockets, and other tissues. It plays a role in retaining collagen, increasing hydration, and providing elasticity and flexibility.
The Size, Characteristics, and Applications of Hyaluronic Acid
Hyaluronic acid has the remarkable ability to hold 500 to over 1000 times its weight in water, making it widely recognized as one of the best hydrating ingredients. It is extensively used in skincare and cosmetic products. Apart from being a component of the extracellular matrix, hyaluronic acid exhibits various physicochemical properties in different parts of the body, which hold significant implications for anti-aging treatments.
- Beauty and Skincare: Due to its water-retention properties, hyaluronic acid is now a foundational ingredient in face masks and skincare products.
- Medical Aesthetics: It’s frequently used in subdermal injections to fill depressions, scars, increase volume, and reduce wrinkles.
- General Medical Use: Injected into joints, it enhances lubrication, reduces discomfort from joint friction, and alleviates knee pain.
- Oral Supplements: Orally consumed hyaluronic acid gets digested and absorbed, then transported to the tissues requiring hyaluronic acid for utilization.
Hyaluronic acid comes in different molecular weights, each with distinct applications:
- High Molecular Weight Hyaluronic Acid: Ranging from 1 to 2.2 million Daltons, it is suitable for providing structural support.
- Medium Molecular Weight Hyaluronic Acid: Ranging from 50,000 to 1 million Daltons, it aids in softening the skin’s stratum corneum and maintaining its health.
- Low Molecular Weight Hyaluronic Acid: Ranging from 5,000 to 50,000 Daltons, it helps retain moisture within the stratum corneum, preventing dryness.
What is the composition of hyaluronic acid?
Hyaluronic acid is a polymer of disaccharides, composed of D-glucuronic acid and N-acetylglucosamine, linked through alternating glycosidic bonds. The length of this polymer can extend up to 25,000 disaccharide repeats.
Hyaluronic acid exhibits a wide range of molecular sizes. The average molecular weight in synovial fluid of the body is around 3 to 7 million Daltons, while hyaluronic acid purified from human umbilical cord is typically around 3 million Daltons.
Hyaluronic acid also contains silicon, its concentration varying depending on its location within the biological organism. Different molecular sizes are crucial for various functions of hyaluronic acid. Larger molecules are found in healthy tissues and contribute to controlling reactions such as inflammation/free radical damage and dehydration (anti-angiogenesis and immunosuppression).
Conversely, smaller hyaluronic acid polymers can signal the immune system and trigger inflammatory responses to aid in wound healing.
Recommended Evidence-Based Benefits of Hyaluronic Acid
1. Promotes Healthier, Softer Skin
Around half of your body’s hyaluronic acid is present in your skin, where it binds to water to aid in hydration. Supplementing with hyaluronic acid can counteract the natural aging process and reduce its decline in the skin due to exposure to factors such as UV rays, tobacco smoke, and pollutants.
💡 Hyaluronic acid supplementation can help increase skin hydration and reduce the appearance of fine lines and wrinkles. [1][2].
💡 Topical hyaluronic acid treatments can alleviate redness and skin inflammation[3] [4][5].
💡 Injectable hyaluronic acid can enhance skin tightness and firmness [6] [7].
2. Accelerates Wound Healing
Hyaluronic acid naturally exists in the skin and plays a critical role in wound healing, with its concentration increasing when repair is required [8] [9].
💡 Direct application of hyaluronic acid to open wounds can help expedite the recovery process. Applying it to skin wounds has been shown to reduce wound size and alleviate pain[10][11] [12][13].
💡 Hyaluronic acid also possesses antibacterial properties, reducing the risk of infection when applied directly to open wounds[14][15].
💡 It is also effective for eliminating ulcers and accelerating healing after dental procedures when used topically in the oral cavity[16].
3. Maintains Joint Lubrication and Alleviates Joint Pain
Hyaluronic acid is present within joints, aiding in maintaining proper lubrication between bones.
💡 Hyaluronic acid is highly beneficial for individuals with osteoarthritis. Research indicates that for patients between 40 and 70 years old, daily consumption of 80-200 milligrams for at least two months can significantly reduce knee joint pain in osteoarthritis patients[17][18] [19][20].
💡 Direct injection of hyaluronic acid into joints is also used to alleviate pain[21] [22].
4. Relief for Gastroesophageal Reflux Symptoms
Research indicates that hyaluronic acid can help alleviate symptoms of gastroesophageal reflux, aiding in the accelerated recovery of the damaged esophageal lining.
💡 Combination supplements containing hyaluronic acid and chondroitin sulfate have been shown to help reduce symptoms of gastroesophageal reflux [23] [24] [25].
5. Alleviation of Dry Eye Syndrome and Discomfort
Hyaluronic acid’s exceptional moisturizing properties make it effective for treating dry eye syndrome.
💡 Eye drops containing 0.2-0.4% hyaluronic acid have been proven to alleviate dry eye symptoms and improve eye health [26][27][28].
💡 Extended-release contact lenses containing hyaluronic acid are also being developed as a potential treatment for dry eye syndrome[29][30].
💡 Hyaluronic acid eye drops are commonly used in ophthalmic surgery to reduce inflammation and accelerate wound healing[31][32].
6. Maintenance of Bone Strength
High doses of hyaluronic acid contribute to the prevention of bone loss.
💡 Animal studies have shown that hyaluronic acid can help slow down the rate of bone loss in rats[33] [34].
💡 Cellular research results also suggest that high doses of hyaluronic acid can enhance the activity of osteoblasts, which are bone-forming cells[35][36].
7. Prevention of Bladder Pain
Research has found that direct insertion of hyaluronic acid into the bladder via a catheter helps alleviate pain and frequent urination associated with interstitial cystitis or painful bladder syndrome[37] [38][39].
Currently, the exact mechanisms through which hyaluronic acid helps alleviate these symptoms are not fully understood. However, researchers speculate that it might assist in repairing damaged bladder tissue, thus reducing its sensitivity to pain[40] [41].
Which is Better: Topical or Oral Hyaluronic Acid?
The effectiveness of hyaluronic acid depends on its molecular weight and intended use. The choice between topical application and oral consumption should be based on your specific needs. For skincare, orally consumed hyaluronic acid can help with maintaining moisture in the deeper layers of the skin, enhancing structural support, and providing plumpness. On the other hand, using hyaluronic acid in facial masks or skincare products can assist in locking in moisture on the outer layers of the skin.
Ultimately, both oral consumption and topical application have their merits. It’s recommended to try both methods and determine which one suits you best based on your personal experience and the desired results.
Sources of Oral Hyaluronic Acid
There are two common sources of hyaluronic acid in dietary supplements, both of which are approved by the professional organization. These sources include “chicken comb extract” from natural origins and “Streptococcus zooepidemicus fermentation product” from bacterial fermentation. The daily maximum recommended intake is 80mg.
Both of these sources of hyaluronic acid have been studied for their potential benefits in joint health, beauty, and skin hydration. Therefore, they are both viable options for consumption.
Are there any side effects of Hyaluronic Acid?
Hyaluronic acid is generally considered safe when used as a dietary supplement. However, the following groups are advised to consult a doctor before using it:
- Pregnant or breastfeeding individuals: The impact of hyaluronic acid in these situations has not been thoroughly studied, so it’s recommended to consult a doctor before consumption.
- Individuals with a history of cancer or currently diagnosed with cancer: It’s advisable to avoid its use or consult a doctor before consumption.
