Complete Guide to Collagen Supplements
Not a year goes by that the world of health and fitness isn’t overcome with some new trendy (“fad”) diet, supplement, or training protocol.
From the diet realm, recent trends include keto, carnivore, and something called the “Wildatarian Diet.” Fitness circles have been dominated by at-home, on-demand training programs, such as those offered by the cycling sensation Peloton, where individuals seek to recreate the group-training dynamic from the comfort of their own home.
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For much of the past year, the supplement industry has been entranced in a fascination with both CBD and collagen supplements. In fact, market estimates expect U.S. consumers are to spend upwards of $122 million on collagen products this year. 
Today, we take a look at the latter and see if collagen supplements have anything worthwhile to offer or if it's yet another cash-grab from the supplement industry at large.
Let’s start by reviewing the basics.
What is Collagen and What Does it Do?
Collagen is the most abundant protein in the body and serves as the primary structural protein for your skin, bones, muscles, tendons, ligaments, blood vessels, and GI system and tendons. In fact, collagen may account for up to 35% of whole-body protein content.
As such, you can think of collagen as the “glue” that holds your body together.
The structure-building protein is comprised of 19 different amino acids, but four “main” players are: 
Glycine and proline are the two non-essential amino acids of note here, as they play pivotal roles in wound healing, immune response, joint health, cardiovascular health, and antioxidative reactions. [2,3]
Additionally, glycine also serves as an important building block of creatine and DNA.
Do I Need Collagen Supplements?
You might be wondering at this point that since our bodies naturally produce collagen, why in the world would we need to supplement with it?
Because you want the luscious locks of Fabio! (kidding…)
The truth is that while we do produce collagen each and every day, much like natural testosterone production, collagen synthesis starts to dwindle as we age. Beginning around age 25, our bodies break down more collagen than we make (due to the actions of the enzyme collagenase. This is also why wrinkles, crow’s feet and other signs of skin aging begin to show as we progress in years.
In addition to aging, prolonged exposure to direct sunlight, excessive sugar consumption, drinking alcohol, and smoking all have both been noted to negatively affect collagen synthesis. [4,5,6]
Furthermore, the typical Western diet isn’t particularly abundant in collagen-rich foods, unless you’re in the habit of regularly consuming organ meats and/or bone broth, that is.
So, if sipping on bone broth or having some liver and onions doesn’t sound particularly appetizing, then collagen supplements may provide a quick and convenient means to increasing your body’s production and supply of collagen.
But, picking a collagen supplement isn’t as simple as it may seem.
You see, there are 16 different kinds of collagen present in the body, and not all collagen supplements contain the same kind of collagen. 
For what it’s worth, types I and II account for the lion’s share of the collagen in your body.
Type I collagen is found in tendons, ligaments, scar tissue, skin, and bones, while Type II collagen is the form that preserves and protects joints.
Where Do Collagen Supplements Come From?
Since collagen is the primary structural protein of mammals, it should come as no surprise that the collagen used to make supplements come from animal sources.
Typically, the bones, skin, and connective tissue of cows, pigs, chickens, and fish are used as the sources for collagen.
Do Collagen Supplements Work?
Collagen research is still in its infancy, but preliminary evidence indicates supplementing with collagen may reduce aches and pains associated with arthritis, improve skin health, promote wound healing, and guard against muscle loss.
Let’s now take a deeper look at each of the potential benefits of collagen supplementation and see what the research actually says.
Supports Joint Health
As we mentioned above, collagen serves as the main structural protein for both your external structures (skin) and in your internal ones (bones, ligaments, tendons, etc.), and as we age our natural collagen production abilities dwindle, which puts our bodies at a heightened risk for developing joint disorders such as osteoarthritis. 
Intense exercise (usually done with poor form) also can put additional wear and tear on our joints, ligaments and connective tissue, providing a double whammy to our ability to move without pain.
Researchers have theorized that supplementing with collagen may help stimulate the body’s endogenous production of collagen, which may help reduce inflammation and joint pain while simultaneously providing the building blocks (amino acids in collagen) to fortify our internal structures.
And, based on preliminary findings, collagen supplements may actually help alleviate joint pain. [9,12,13]
A study in healthy athletes found that those who consumed 10g of collagen hydrolysate per day for 6 months experienced a significant reduction in joint pain both at rest and while walking compared to the control group. 
Another study, this time in healthy adults suffering from osteoarthritis, noted that participants who consumed 2g daily of BioCell UC-II Collagen for 70 days experienced significant improvements in visual analogue scale (VAS) for pain and Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores compared to the placebo group. 
Note: WOMAC is a standardized questionnaire used by healthcare professionals to assess the condition of patients with osteoarthritis of the hip and knee. Variables tracked by WOMAC include stiffness, pain, and physical function of the joints.
Subjects in the above study also reported that they were more apt to participate in physical activity than those receiving the placebo. 
If you want to test the potential pain-relieving effects of collagen for yourself, the current body of evidence suggests supplementing with ~10g collagen hydrolysate per day or 2g BioCell UC-Collagen.
Note: BioCell Collagen contains a naturally derived matrix of Type 2 Hydrolyzed Collagen + Hyaluronic Acid + Chondroitin Sulfate noted to increase levels of all three major collagen types (I, II, & III) as well as reduce joint pain and discomfort.
Promotes Healthy Skin
Not only does collagen provide structural support for the skin, it also plays a role in hydration and elasticity. The declining collagen production that coincides with aging is one of the primary reasons we develop wrinkles as well as dry skin.
If you spend any time researching collagen supplements, you’ll likely encounter countless anecdotes attributing improved skin appearance and quality.
And as it turns out, there is some research to back up these numerous “n=1s”.
A number of clinical trials conducted in healthy humans have found that supplementing with collagen or collagen peptides (2.5-5 grams per day) can help reduce skin dryness and wrinkling as well as improve the elasticity of the skin, slowing the visible aging of the skin. [15,16,17]
As we mentioned when discussing collagen’s impact on joint health, researchers attribute these “anti-aging” effect to collagen supplements ability to stimulate our bodies to produce more collagen. [15,18]
On top of that, consuming supplemental collagen may also boost the production of elastin and fibrillin, two other proteins that provide structural support for the skin.
Aids Cardiovascular Health
While the majority of scientific evidence backing the use of collagen lies in the areas of joint pain and skin health, further research is starting to unearth some other potential benefits of the versatile protein.
One of the more intriguing areas where collagen supplements may help is cardiovascular-related conditions.
Since collagen serves as a fundamental structural protein for your arteries, having insufficient levels (or production) of collagen may lead to weakening of the arteries and eventual atherosclerosis. 
An open-label, single-dose trial including 32 healthy adults (16 males and 16 females) investigated the effects of six months daily supplementation with collagen tripeptides on markers of atherosclerosis. Individuals taking part in the trial had not previously received treatments for cardiovascular disease or diabetes.
Subjects consumed 8 grams of collagen tripeptides twice daily (16 grams in total per day) daily for six months.
At the end of the 6-month trial, researchers documented significant improvements (avg. 6% increase) in “good” HDL cholesterol as well as significant reductions in measures of artery stiffness compared to baseline measurements. 
Within the study, researchers also postulate that since collagen tripeptides may have potential benefit for the prevention of diabetes since the main component of it (glycine, proline, and hydroxyproline) inhibit dipeptidyl peptidase-IV (DPP-4) activity. 
In case you weren’t aware, DPP-4 inhibitors are a class of oral hypoglycemic drugs doctors prescribe in the treatment of diabetes. DPP-4 inhibitors reduce glucagon, increase insulin secretion, decrease gastric emptying and lower blood glucose levels. 
More studies are needed vet the full potential of collagen supplement and cardiovascular health, but for now, the findings of this one study are more than enough to pique the public’s interest.
May Prevent Bone Loss
As we age bone mass (and collagen) deteriorates, setting up the potential for the development of osteoporosis as well as an increased risk of bone fractures. [22,23]
Several human studies have found that ingesting collagen supplements may help prevent bone breakdown that leads to osteoporosis.
Two different studies, both involving women who consumed 5 grams of collagen daily for 12 months, documented increases in bone mineral density compared the those receiving a placebo. [24,25]
As you may know, bone mineral density is an important marker used by doctors to measure the mineral content of your bones. Individuals with low bone mineral densities typically have frail bones and develop osteoporosis.
Much like the collagen supplements-cardiovascular health link, preliminary findings on the role of collagen supplements in bone health is intriguing, but far from making it a “proven commodity.”
Potential Muscle Protector
Collagen makes up between 1–10% of skeletal muscle tissue. 
Research in subjects with sarcopenia (age-related muscle wasting) has found that supplementing with 15 grams of collagen peptides daily for 12 weeks (in conjunction with a structured exercise program) gained significantly more muscle and strength compared to the control group who only exercised but received no collagen. 
Individuals receiving the collagen peptides also lost more body fat than the group that exercised by didn’t receive collagen.
Researchers theorized that the supplemental collagen may have fostered greater creatine production, since glycine is one of the building blocks used to make the muscle-building compound and collagen is particularly rich in glycine.
It’s worth noting that there hasn’t been much research in young, healthy, resistance-trained individuals and collagen supplementation. Due to the low leucine content of collagen, it’s not nearly as powerful of a mTOR pathway stimulator as whey protein, but collagen isn’t really being billed so much as a “muscle building” supplement as it is a joint and beauty one.
Other Potential Benefits
The two benefits or “claims” for which there is the largest body of evidence with regards to collagen supplements are in the areas of joint health and skin care. That being said, collagen is often recommended to improve a number of other things, including:
Gut Health: collagen plays a major role in the function and integrity of your digestive system. Namely, it regulates the amount of gastric juices released into the stomach, regulating the amount of stomach acid, which helps protect against heartburn, stomach ulcers, and other painful GI issues.
Additionally, glycine and proline are two of the main building blocks of collagen and have been noted to help heal the lining of the gut. And, low levels of collagen have been associated with various gastrointestinal disorders, such as IBS. Supplementing with collagen may help reinforce the gut lining and improve gut health, but more research is needed to validate these ideas.
Immune Function: Glycine is an important immunomodulator and it’s believed that supplementing with collagen will increase glycine concentrations in the body to help promote healing and limit unhealthful, chronic inflammation. Again more research is needed to vet these claims.
Improved Sleep: the reason collagen is recommended by some for sleep is again due to its high glycine content. Glycine has been shown in a few studies to improve sleep latency (how fast you fall asleep), reduce fatigue, improve mental clarity the morning after, and how “deep” your sleep is. [30,31]
Liver Health & “Detoxification”: again it’s glycine that’s at the forefront it is needed to produce glutathione production, one of the most powerful antioxidants in the body. 
The liver also uses glycine for “phase 2 detoxification” -- one of the main pathways involved in detoxifying the body. Phase-2 detoxification converts fat-soluble toxins into water-soluble chemicals that can then be excreted out through urine and bile.
Collagen is the most abundant protein in the body, impacting everything from your appearance to your joint health.
From the current body of evidence, the two claims that have the most backing are in support of collagen for joint health and skin care. If you’ve been dealing with cranky knees and elbow for some time or looking to restore the “glow” of your youth, supplementing with collagen may be something worth trying out.
As for the rest of the claims surrounds collagen, the jury is still out from the research communities point of view.
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