Benefits and side effects of collagen supplements

Do Collagen Supplements Work?

We see collagen typically advertised as an important ingredient in beauty products, which promise to provide healthy, youthful skin. But it’s also in nearly all of the meat that we eat, and extremely abundant in our body.
But what exactly is collagen? How does it contribute to healthier skin?
And are there benefits to taking it as a supplement?


What is Collagen?

Collagen is a protein made up of amino acids formed into a triple-helix structure. It is abundant in humans, making up 25 – 30% of the protein content in each of our bodies, more than any other protein. In fact, it is the most abundant protein in the entire animal kingdom.

There are 16 different types of collagen, by molecular make up, but their main purpose, generally speaking, is to protect tissues from stretching too much. Collagens bind together to form thin, long, and very strong fibers that arrange themselves together in parallel bundles to provide structure and strength as they connect tissues and bones throughout the body.

Perhaps the best understanding of the function of collagen can be seen in our skin. We can stretch our skin quite a bit, but it’s doesn’t tear easily, and snaps back in place once released. As we grow older, our skin loses its resiliency as a result of losing collagen. It doesn’t snap back as easily, creating wrinkles and rough patches that we associate with aging. This process can be accelerated by cigarette smoke, excess sunlight, and high blood sugar.

It can also be accelerated by stress, which produces cortisol. Cortisol impedes collagen production in the body, which is likely why those who are overworked or anxious often appear to age faster.

The collagen in our skin is also responsible for healing wounds, by guiding the connective tissue and interacting with blood platelets to stop bleeding. These properties are what make collagen, typically taken from humans, cows, or pigs, so useful for surgeons performing skin grafts.

It has plenty of non-medical uses, as well. Many foods contain collagen, where it is often referred to as gelatin. In the musical world, many appreciate the sound that collagen provides when used for violin or guitar strings. Beauty products may also have collagen, as do several shampoos.

However, the use most associated with collagen is likely glue, which was often produced by collagen derived from horses. In fact, the name collagen comes from the ancient Greek kóllagen: “Producing glue.” Today, these animal glues are rarely used outside of specialized fields.

We get collagen in our diet any time we eat foods with gelatin in them, though our body can produce its own collagen out of amino acids, most importantly glycine and proline, which are found in most foods we eat including (but not limited to) most meats, nuts, seeds, dairy products, and healthy greens.

Collagen and Vitamin C

Collagen requires ascorbic acid (Vitamin C) to form. When deprived from the essential vitamin, collagens can’t form into their triple helix structure or combine with other collagens to create fibers. As a result, blood vessels become weaker and break more easily, causing bleeding and bruising, skin becomes rougher, and gums lose their ability to hold teeth — all symptoms seen in patients suffering from scurvy, a vitamin C deficiency. Today, in industrialized countries, scurvy is very rare, though it was more common in past centuries, particularly in sailors who didn’t have access to citrus fruits on their long journeys.

Skin Benefits

Recent studies have found evidence that collagen, either applied externally and orally ingested, has positive effects on the skin, increasing moisture and elasticity, while decreasing both roughness and wrinkles. These studies, on the whole, are fairly small scale, only having on the order of 100 participants or less, typically. However, the results are statistically significant and, at least according to one study, visibly noticeable.

One promising study looked at the effect of collagen supplementation on cellulite levels and found that a 2.5 g daily collagen supplement significantly decreased the appearance of cellulite in all participants. This decrease was especially pronounced in participants with a body-mass index (BMI — a way of measuring and comparing weights for people of different heights) below 25, indicating that they were not overweight. However, there was a statistically significant reduction in all groups when compared to appropriate controls. Though, like the previous studies, this one suffered from small sample size (97 participants), it had extremely strict protocol, requiring subjects refrain from using any oily skin products or expose themselves to excess UV rays during the experiment as well as demanding they not visit spas or saunas, participate in intensive sports, or receive professional massages.

Based on these small studies, it’s not unreasonable to believe that supplemental collagen can improve skin health, but it’s unclear whether or not long-term collagen use can prevent wrinkles or cellulate from ever occurring. Large-scale studies over twenty-year periods or more haven’t been carried out at this point in time.

Collagen and Muscle Repair

A study looking at men older than 65 who experienced age-related muscle loss found that they could rebuild muscle if they participate in a guided fitness training program. However, the study found that those who took a collagen supplement along with the program rebuilt more muscle and lost more fat. Again, this study suffered from small sample size (fewer than 60 participants in total), and though the results are promising, they’re considered controversial by the scientific community at large, in part because there’s no clear explanation of how the administered dosages of collagen could have accounted for the change.

Collagen for Osteoporosis and Osteoarthritis

Again, in small studies, collagen supplements have improved conditions for those suffering from osteoporosis and osteoarthritis. This is complicated because, although both diseases relate to bone — with osteoporosis characterized by weak bones and osteoarthritis a result of joint damage between bones — they’re not positively associated with each other. In fact, the presence of osteoarthritis can reduce the risk of osteoporosis, though it is still possible for a person to suffer from both.

It’s also complicated because there’s not a clear proven mechanism for why collagen may reduce symptoms of either condition, though there are several candidate hypotheses.

One suggests that, by taking oral supplements and exposing the body to more collagens, one develops a tolerance for the protein, which reduces an immune response. The problem with this idea is that, unlike other forms of arthritis, osteoarthritis isn’t an autoimmune disease, and neither is osteoporosis, so it’s unlikely that this explains the success of oral supplements.

Another idea is that ingested collagen is used as the building blocks for bone and cartilage, thus preventing deterioration around joints, though studies have produced conflicting results, some of which support this idea and some that appear to contradict it. Other proposed ideas offer a more indirect approach, suggesting that collagen lowers blood pressure which, in turn, improves symptoms.

Overall, regardless of the reason, there are studies that seem to suggest that supplemental collagen may help those suffering from osteoporosis, osteoarthritis, or both, with relatively limited risk. However, these supplements should only be taken alongside physician recommended medications and never as a substitute for them.

Collagen Supplementation

One of the main sources of skepticism behind all of these proposed benefits attributed to collagen supplementation is the question of whether or not collagen can even be absorbed into the blood, rather than just passed through the digestive system. However, multiple studies have demonstrated that ingested collagen can make its way into the bloodstream. One of these studies administered a collagen labeled with a radioactive form of carbon and found that not only was it absorbed into the mouse’s system, detectible levels remained there for over a week.

Studies involving mice are easier to control but suffer from the problem that what’s true for mice may not be true for humans. Follow-up studies looking at humans revealed increased collagen levels in the blood after about 30 minutes of ingesting various forms of gelatin. It remained at elevated levels for at least a few hours after taking the supplement before petering out, but the experiment demonstrates that collagen can be absorbed by the intestines and provides a mechanism for how supplementation could produce benefits. Other studies have found that several hours of fasting followed by a high collagen meal resulted in detectible levels of collagen in human plasma, as well, giving even more support to the idea of the protein being the responsible agent behind the observed benefits.

Collagen Side Effects

Though more and better research would be helpful to determine the healthful benefits of collagen, it’s clear that, in low doses, there’s little risk involved in taking it as a supplement. It’s worth noting, however, that it is possible to have an allergy to particular types of collagen. In many cases, these result in mild symptoms such as skin irritation, though flu symptoms have also been reported and, in extreme cases, patients have needed hospitalization following severe swelling and, in at least one case, anaphylaxis after a child was given cold medicine in the form of a gel capsule. Though these cases are rare in isolating collagen, it’s possible that there are more out there where the allergic reaction may not be appropriately attributed, and collagen is the true cause. One study, for instance, found that as many as 50% of fish allergies could be related to collagen.

Overall, though, collagen is safe. In order to be cautious, it’s best to start with low dosages and, in topical solutions, apply a small amount to test areas on your skin before using it on your face.

Do Collagen Supplements Work?

Collagen is a protein produced by many animals, often found in bone and cartilage, but also prevalent throughout the body. It’s been used to produce glue, but today can be found more commonly in desserts and beauty products. Several studies have looked into its benefits, but they haven’t been fully explored.

Overall, studies have suggested that collagen may have anti-aging properties on the skin and has the potential to reduce symptoms of osteoporosis and osteoarthritis in addition to aiding in rebuilding strength in older men who have lost muscle due to age. The main risks associated with supplemental collagen are allergic reactions, which are rare and generally not severe, though they can be, so exercise some caution when using collagen, particularly if you have fish allergies.


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