Collagen is the most plentiful protein in the body.
It has important roles, including providing structure to your skin and helping your blood clot.
In recent years, it has gained popularity as a nutritional supplement and ingredient in shampoos and body lotions.
But what is collagen? And what is it good for? This article gives you a thorough overview of this important protein.
Collagen is the most abundant protein in your body, accounting for about a third of its protein composition.
It's one of the major building blocks of bones, skin, muscles, tendons and ligaments. Collagen is also found in many other body parts, including blood vessels, corneas and teeth.
You can think of it as the "glue" that holds all these things together. In fact, the word comes from the Greek word "kólla," which means glue.
Below is an illustration of collagen's molecular structure:
Bottom Line: Collagen is a protein that provides structure to much of your body, including bones, skin, tendons and ligaments.
There are at least 16 types of collagen. The four main types are type I, II, III and IV ().
Here's a closer look at the four main types of collagen and their role in your body:
- Type I: This type accounts for 90% of your body's collagen and is made of densely packed fibers. It provides structure to skin, bones, tendons, fibrous cartilage, connective tissue and teeth.
- Type II: This type is made of more loosely packed fibers and is found in elastic cartilage, which cushions joints.
- Type III: This type supports the structure of muscles, organs and arteries.
- Type IV: This type helps with filtration and is found in layers of your skin.
As you age, your body produces less and lower-quality collagen.
One of the visible signs of this is in your skin, which becomes less firm and supple. Cartilage also weakens with age.
Bottom Line: There are at least 16 types of collagen. It's found throughout your body, providing structure and support.
All collagen starts off as procollagen.
Your body makes procollagen by combining two amino acids: glycine and proline. This process uses vitamin C.
You may be able to help your body produce this important protein by making sure you get plenty of the following nutrients:
- Vitamin C: Large amounts are found in citrus fruits, bell peppers and strawberries ().
- Proline: Large amounts are found in egg whites, wheat germ, dairy products, cabbage, asparagus and mushrooms ().
- Glycine: Large amounts are found in pork skin, chicken skin and gelatin, but glycine is also found in various protein-containing foods ().
- Copper: Large amounts are found in organ meats, sesame seeds, cocoa powder, cashews and lentils (, ).
Bottom Line: Four of the nutrients that help produce collagen are vitamin C, proline, glycine and copper. Also, eating high-quality protein gives your body the amino acids it needs.
Perhaps it's even more important to avoid the following collagen-destroying behaviors:
- Sugar and refined carbs: Sugar interferes with collagen's ability to repair itself. Minimize your consumption of added sugar and refined carbs ().
- Too much sunshine: Ultraviolet radiation can reduce collagen production. Avoid excessive sun exposure ().
- Smoking: Smoking reduces collagen production. This can impair wound healing and lead to wrinkles ().
Some autoimmune disorders, such as lupus, can also damage collagen.
Bottom Line: You can help your body preserve and protect collagen by avoiding behaviors that damage it. These include eating excessive amounts of sugar, smoking and getting sunburned.
Collagen is found in the connective tissues of animal foods. For example, it's found in large amounts in chicken and pork skin.
One particularly rich source is bone broth, which is made by boiling down the bones of chicken and other animals.
Gelatin is basically cooked collagen, so it is very high in the amino acids needed to produce it.
But there's debate over whether consuming collagen-rich foods actually increases the levels in your body.
When you eat protein, it's broken down into amino acids and then reassembled, so the collagen you eat wouldn't translate directly into higher levels in your body.
Bottom Line: Animal products such as bone broth, gelatin, chicken skin and pork skin are very high in collagen.
Two types supplements are gaining popularity: hydrolyzed collagen (collagen hydrolysate) and gelatin. Gelatin is created when collagen is cooked.
These have already broken the large protein down into smaller peptides, which are more easily absorbed in the body.
There aren't many studies on collagen supplements, but those that exist show promise for benefits in the following areas:
- Muscle mass: A 2015 study in elderly men showed that a combination of collagen peptide supplements and strength training increased muscle mass and strength more than a placebo ().
- Arthritis: Another study gave supplements to people suffering from osteoarthritis. They experienced a significant decline in pain over the 70-day study, compared to those who took a placebo ().
- Skin elasticity: Women who took a supplement showed improvements in skin elasticity in a 2014 study. Collagen is also used in topical treatments to improve the appearance of skin by minimizing lines and wrinkles (, ).
Some alternative medicine practitioners also advocate using collagen supplements to treat leaky gut syndrome.
Bottom Line: According to studies, supplemental collagen may help improve skin texture and muscle mass and reduce osteoarthritis pain.
So far, there's not very reliable information on the safety or efficacy of collagen supplements.
The potential side effects of gelatin supplements include a lingering unpleasant taste and sensations of heaviness and heartburn.
Also, if you're allergic to the source of the supplement, then you could have an allergic reaction.
Bottom Line: There are no substantial reports of side effects. However, you could have an allergic reaction if you're allergic to the supplement source.
Collagen peptide comes in a powder that can be easily incorporated into foods.
The peptide form does not gel, so you can mix it into smoothies, soups or baked goods without affecting the texture.
You can use gelatin to make homemade jello or gummies. Check out .
When considering supplements, you should look for a high-quality source. Marine collagen, which is made from fish skin, is also available.
Bottom Line: You can find supplements in pill or powder form. The powder can be easily added to food.
Collagen has many uses, from food to medicine to manufacturing.
For thousands of years, it was used to create glue. Today, it's still used to create strings for musical instruments.
In food, it's heated to create gelatin and used to make casings for sausages. In the medical field, it's used as a filler in plastic surgery and as a dressing for severe burns.
Bottom Line: Collagen has many uses, including as a dressing on burns and in making strings for musical instruments.
Collagen is an important protein that provides structure for many parts of the body.
Interestingly, the foods and nutrients you eat can help your body make this protein.
Alternatively, collagen supplements may be beneficial as well. Some preliminary studies show that they may improve skin quality, muscle function and reduce the pain associated with osteoarthritis.