Rumor debunked: Eating collagen can beautify your skin!

In today's society, as people's pursuit of beauty increases, the beauty and anti-aging markets are booming. As a well-known beauty ingredient, collagen is widely used in skin care products, health products and food. Many people believe that oral collagen supplements or eating foods rich in collagen can effectively improve skin elasticity, reduce wrinkles, and even delay aging. However, is there any scientific basis for this statement? Can eating collagen really improve beauty? This article will analyze this widely circulated health misunderstanding from a scientific perspective to help the public correctly understand the relationship between collagen and beauty.

1. The physiological role and importance of collagen

Collagen is the most abundant protein in the human body, accounting for 25%-35% of the total protein in the human body. It is widely present in connective tissues such as skin, bones, tendons, and cartilage, and is an important component for maintaining skin elasticity and structure. The fibrous structure of collagen gives skin and tissue strength and elasticity, while playing a key role in wound healing and tissue repair.

As we age, collagen synthesis in the human body gradually decreases, leading to signs of aging such as wrinkles, looseness and sagging on the skin. Therefore, supplementing collagen seems to be a "shortcut" to fight aging. However, whether oral collagen can really achieve beauty effects still needs to be analyzed from a scientific perspective.

2. Digestion and absorption mechanism of collagen

To understand whether oral collagen can improve beauty, we first need to understand the digestion and absorption process of collagen in the human body. Collagen is a large molecule protein with a molecular weight of usually more than 100,000 Daltons. When people ingest collagen, it is broken down into smaller peptides and amino acids in the gastrointestinal tract.

Studies have shown that collagen is broken down into small peptides and free amino acids by digestive enzymes such as pepsin and trypsin in the gastrointestinal tract. These small peptides and amino acids are then absorbed into the blood circulation and transported to various tissues throughout the body. However, after entering the blood circulation, these small peptides and amino acids are not directly deposited in the skin in the form of collagen. Instead, they are taken up by cells and resynthesized into proteins needed by the human body, including collagen.

Therefore, oral collagen does not directly replenish collagen in the skin, but works indirectly by providing the amino acids required for collagen synthesis. However, whether this indirect effect can significantly improve skin elasticity and reduce wrinkles still needs further verification.

3. The relationship between oral collagen and skin health

In recent years, a number of scientific studies have explored the effects of oral collagen on skin health. The results of these studies are inconsistent, with some studies showing that oral collagen may have a certain improvement effect on the skin, while other studies have found no significant effect.

1. Research supporting the beauty effects of oral collagen

Improved skin elasticity and moisture content

A study published in the Journal of Skin Pharmacology found that after taking collagen supplements for 12 weeks, the subjects' skin elasticity increased significantly and their skin moisture levels also improved. Another study also pointed out that oral collagen peptides can significantly reduce skin wrinkles and improve the overall appearance of the skin.

Stimulation of collagen synthesis

Some in vitro experiments have shown that collagen peptides can stimulate the activity of skin fibroblasts and promote collagen synthesis. This suggests that oral collagen may indirectly promote the production of skin collagen by providing the amino acids required for collagen synthesis.

(II) Research questioning the beauty effects of oral collagen

Lack of long-term effects

Although some short-term studies have shown that oral collagen may improve skin, these effects are usually temporary and do not appear to improve skin in the long term.

Individual Differences

The effects of oral collagen vary from person to person and are affected by factors such as individual genes, lifestyle, and dietary habits. Some people may respond better to collagen supplements, while others may not see significant effects.

Lack of high-quality evidence

Currently, most studies supporting the cosmetic effects of oral collagen are short-term studies with small sample sizes, lacking large-scale, long-term clinical trial support. In addition, many studies did not adopt a double-blind control design, which may have certain biases.

4. Why can’t oral collagen be used directly for beauty treatments?

Although oral collagen may have some indirect effects on the skin, its cosmetic effects have many limitations:

1. Limitations of digestion and absorption

During digestion, collagen is broken down into small peptides and amino acids. After these components enter the blood circulation, they cannot be directly deposited in the skin. The synthesis of skin collagen is a complex biological process involving the regulation of multiple cell signaling pathways and gene expression. It is difficult to directly promote the synthesis of skin collagen simply by taking oral collagen supplements.

2. Complexity of skin aging

Skin aging is a complex biological process that is affected by many factors, including genes, environment, lifestyle, and hormone levels. Ultraviolet exposure, environmental pollution, smoking, and poor eating habits can accelerate skin aging. Simply relying on oral collagen supplements cannot fully solve the problem of skin aging.

3. Lack of Targetedness

Oral collagen supplements provide non-specific amino acids that can be used by the body to synthesize a variety of proteins, not just skin collagen. Therefore, the effects of oral collagen lack specificity and it is difficult to directly improve skin elasticity and wrinkles.

5. Truly effective beauty method: Maintain a healthy lifestyle

Although oral collagen may have some indirect effects on the skin, its cosmetic effect is not significant. Really improving skin health and delaying aging requires comprehensive lifestyle changes, including a proper diet, sun protection, moderate exercise and good living habits.

1. Healthy diet

Foods Rich in Antioxidants

Antioxidants can neutralize free radicals and reduce oxidative stress damage to the skin. It is recommended to eat more foods rich in vitamin C, vitamin E, selenium and flavonoids, such as fruits, vegetables, nuts and green tea.

High-quality protein intake

In addition to collagen, other high-quality proteins, such as fish, lean meats, beans, and eggs, are also beneficial for skin health. These foods provide amino acids that the body uses to build collagen and other proteins.

Omega-3 fatty acids

Omega-3 fatty acids have anti-inflammatory effects and can improve skin elasticity and radiance. It is recommended to consume 2-3 servings of foods rich in omega-3 fatty acids per week, such as deep-sea fish, flax seeds, and walnuts.

2. Sun protection

UV rays are one of the main causes of skin aging. Long-term exposure to UV rays can cause wrinkles, spots, and sagging of the skin. It is recommended to use sunscreen every day and avoid going out during the period when UV rays are strong (10 am to 4 pm). In addition, wearing a hat and sunglasses can also effectively protect the skin.

3. Exercise moderately

Moderate exercise can promote blood circulation and increase blood supply to the skin, thereby improving the nutritional status and metabolic function of the skin. It is recommended to do at least 150 minutes of moderate-intensity aerobic exercise per week, such as brisk walking, jogging or swimming.

4. Good living habits

Quit smoking and limit alcohol consumption

Smoking and excessive drinking can accelerate skin aging, leading to wrinkles and spots. Quitting smoking and limiting alcohol consumption can help improve skin health.

Get enough sleep

Lack of sleep can lead to dull skin and increased wrinkles. It is recommended to maintain 7-9 hours of high-quality sleep every day.

Managing stress

Chronic stress can accelerate skin aging. Managing stress through meditation, yoga, or deep breathing can help keep your skin healthy.

VI. Conclusion

Collagen is an important component for maintaining skin health, but oral collagen supplements do not have significant cosmetic effects. Scientific studies have shown that collagen is broken down into small molecule peptides and amino acids during digestion, and these components cannot be directly deposited in the skin after entering the blood circulation. To truly improve skin health and delay aging, comprehensive lifestyle changes are required, including a proper diet, sun protection, moderate exercise, and good living habits.

[Fund Project] Shanghai Rehabilitation Medicine Association "Health Management Research Fund" Science Popularization Project (No.: 2024JGKP03), Shanghai Pudong New Area People's Hospital Science Popularization Talent Capacity Improvement Project (No.: PRYKP202501)

[Author] Chen Ye, Dong Yafen, Jin Hui, Shanghai Pudong New Area People's Hospital