In the human body, collagen starts to decline from the ages of 18-29, with an annual loss of approximately 1% after the age of 40. By around 80 years of age, the total production of collagen in the body decreases by 75% compared to young individuals [1]. Numerous studies have indicated that oral supplementation of collagen can promote wound healing and improve skin aging[3], as well as aid in reducing and preventing joint pain and bone density loss [4]. If you intend to enhance your health by supplementing collagen, it is advisable to refer to the introduction provided in this article before making a purchase.
What are the types of collagen in the human body?
In general, the human body contains three main types of collagen:
- Type I Collagen, which forms fibers in various tissues except for cartilage.
- Type II Collagen, which forms fibers in cartilage.
- Type III Collagen, which is present in blood vessels and internal organs, and has a structure similar to Type I Collagen.
1. Type I Collagen: This type primarily forms collagen fibers in tissues other than cartilage. It includes fibers in bone, tendons, ligaments, and most other connective tissues except for cartilage. More than 90% of the collagen in the body is Type I Collagen. It provides strength and elasticity to structures such as bone, tendons, and ligaments. It is relatively abundant in tendons and ligaments compared to other tissues. Additionally, the content of elastic proteins and non-collagen components, like lipids, in the skin is higher compared to tendons.
2. Type II Collagen: This type primarily forms collagen fibers in cartilage. Type II Collagen plays a significant role in preventing and improving osteoarthritis. An animal study indicated that consuming Type II Collagen extracted from chicken cartilage can effectively enhance mechanical functionality in injured knee joints of mice and prevent excessive degradation of joint cartilage.[2][5][6][7]
What are the benefits of collagen?
Anti-Cancer Effects
Many studies on the extracellular matrix suggest that Type I Collagen can restrict the proliferation of cancer cells.
💡Melanoma cells respond to growth-regulatory signals from fibrous collagen, which can impede the cell cycle progression of melanoma cells, thus inhibiting cancer cell growth. However, this doesn’t directly affect cell apoptosis[8].
💡Fibrous collagen can inhibit the growth cycle of human non-small cell lung cancer cells[9].
Research integrates various experiments and indicates that the presence of Type I Collagen is necessary to restrict tumor cell proliferation[9].
Maintaining Skin Elasticity and Hydration
Collagen functions in the dermis in two distinct forms:
- Free amino acids provide the basis for the formation of collagen and elastin fibers.
- Collagen peptides, when paired with receptors on fibroblast membranes, stimulate the production of new collagen, elastin, and hyaluronic acid[11].
💡Clinical studies demonstrate that continuous supplementation with collagen for 8 weeks significantly increases skin hydration. After 4 weeks of continuous supplementation, there is a significant increase in collagen density in the dermis and a reduction in collagen fragmentation. These effects persist after 12 weeks, concluding that collagen supplementation effectively improves skin aging[12].
Improving Bone Density
Collagen plays a vital structural role in several organs, particularly in bone and cartilage.
💡Research on mice fed diets containing either 10 grams or 25 grams of hydrolyzed collagen per kilogram of body weight for 12 weeks found that the group fed the higher amount of hydrolyzed collagen exhibited significantly increased bone strength and higher bone mineral density. This indicates that hydrolyzed collagen has a positive impact on bone metabolism and can help improve bone density[14].
💡Another study involving mice showed that those receiving varying amounts of collagen daily based on body weight for 4 weeks had significantly higher bone density in the femur in the group with the highest collagen intake. Oral collagen supplementation has a beneficial impact on bone metabolism[15].
Improving Osteoarthritis
Type I Collagen has protective, anti-inflammatory, and pain-relieving effects on osteoarthritis.
💡A prospective, randomized, double-blind clinical study focused on elderly women with mild to moderate knee osteoarthritis. After six months of consuming 8 grams of collagen daily, the study found a significant reduction in joint pain and improvement in physical activity[16].
💡Another animal study observed mice with induced meniscus ligament damage in the right knee. Daily supplementation of Type I Collagen provided cartilage protection. The study observed that cartilage area, cartilage cell count, and protein polysaccharide matrix increased with higher collagen supplementation at weeks 3 and 12 post-injury. This suggests that the more collagen supplementation, the better the cartilage recovery[17].
Further Reading: 【2023】Top 5 Recommended Collagen Supplements! Benefits, Selection, and Comparison
Which foods contain Type I Collagen?
We can obtain collagen through regular diet. The richest sources of collagen include pork skin, beef skin, pork cartilage, beef cartilage, chicken feet, and chicken skin[18]. Additionally, collagen also has marine sources, such as fish and other invertebrates like fish skin and jellyfish skin[19].
However, it’s important to note that obtaining collagen from food might lead to excessive calorie, cholesterol, and fat intake. Many people nowadays have meals outside, making it challenging to obtain sufficient collagen through diet alone. Thankfully, there are many health supplements available that provide collagen supplementation, allowing us to achieve our desired health benefits without health burdens.
How to Consume Collagen and When?
Research suggests that continuous supplementation of collagen for 8 to 12 weeks, with an intake ranging from 2.5 to 10 grams, can significantly impact skin health[20][21]. Collagen is best consumed on an empty stomach for better absorption. However, some studies indicate that there might be slight gastrointestinal discomfort after collagen consumption, such as feeling full or experiencing an unpleasant taste[22]. Therefore, for those with weaker digestion, it’s advisable to take collagen after meals.
Furthermore, it’s recommended to consume collagen with vitamin C. Vitamin C plays a crucial role in collagen synthesis, assisting in its production and repair. Therefore, ensuring sufficient intake of vitamin C is also essential for collagen synthesis and repair[23].
Are There Side Effects or Contraindications to Consuming Collagen?
Collagen is a type of protein. Individuals with poor kidney function are advised to consult with a doctor or nutritionist before use. Apart from this, there are generally no significant side effects associated with collagen consumption.
Is Topical Collagen Effective? Which is Better: Topical or Oral Collagen?
Research indicates that molecules with a molecular weight less than 500 Daltons can be directly absorbed by the skin. If the molecular weight is too large, it cannot penetrate even the epidermal layer of the skin, let alone reach the dermal layer. Before hydrolysis, collagen molecules have a large molecular structure (around 100,000-300,000 Daltons), making it impossible for collagen to be absorbed through topical application to reach the dermal layer and promote collagen synthesis. At most, topical collagen might only have a moisturizing effect[24] [25] [26].
To promote skin health, it’s recommended to supplement collagen through oral consumption. After collagen is broken down and absorbed through the gastrointestinal tract, it significantly increases skin hydration, and collagen density in the dermis also increases, effectively improving skin aging[11] [12].
