Should you believe the buzz on collagen?

Fans claim that adding this protein to your diet can improve joint health, erase wrinkles, even help you shed pounds. Before you scoop collagen powder into your morning smoothie, read this scientific review.

Powders and pills and potions, oh my! From social-media feeds to late-night infomercials, fans are touting collagen as a next-generation superfood that can reverse skin aging, ease arthritic joint pain, even accelerate weight loss. According to one forecast, the global market for dietary collagen products could balloon to $7.5 billion by 2027.

Despite collagen’s trendy status, however, questions remain about whether it delivers on its popular health claims. Here’s what independent nutrition experts had to say about the science—and the hype—behind collagen supplements.

What is collagen, exactly?

First things first: Collagen is the most plentiful protein in the human body. It’s the main component found in our connective tissues, including skin, bones, tendons, and cartilage—almost like a glue that holds the body together.

Collagen levels decline with age, generally beginning in our 20s, says registered dietitian Lauren Slayton, MS, founder of Foodtrainers in New York City. The body produces collagen at a slower rate over time; research suggests that by age 80, we’re producing about 25% less collagen than we were in early adulthood.

Existing collagen is also damaged more easily as we grow older. Research suggests that sun exposure, cigarette smoke, and environmental pollution are factors that can hasten the breakdown of collagen in the body’s tissues.

Given collagen’s importance in human physiology, it makes sense to wonder: Could boosting collagen in your diet help offset the body’s losses and support overall health?

Collagen in your diet vs. collagen in your body

In addition to being integral to the human form, collagen is also found in foods such as meats, fish, egg whites, and spirulina. Bone broth contains a concentration of collagen thanks to its extended simmering time. And as noted, collagen supplements have become top-selling nutrition products.

An important fact to know before we go further: The collagen you consume does not directly translate into an equal measure of collagen in the body, says Whitney Linsenmeyer, PhD, RD, LD, a spokesperson for the Academy of Nutrition and Dietetics and assistant professor of nutrition at Saint Louis University in Missouri. “Collagen is digested into individual amino acids, which contribute to the body’s total amino acid pool,” Dr. Lisenmeyer explains. “The liver then draws from this pool to synthesize thousands of proteins the body needs.” Collagen is just one kind.

Are collagen peptides more effective?

Sold in supplement form and frequently used as food additives, collagen peptides are shorter amino acid chains that dissolve easily in liquids. “To use a gross analogy, it’s sort of like collagen that’s already been chewed,” Slayton says.

As a selling point, some marketers claim that the body can absorb collagen peptides (a.k.a. hydrolyzed collagen) more readily than intact collagen. But that’s a straw-man argument, Dr. Lisenmeyer says—there’s no evidence that collagen peptides offer an advantage in boosting the body’s actual collagen stores.

Health claims of collagen: Fact or fiction?

Here’s a closer look at some of the most common health claims associated with collagen.

Claim 1: Collagen reduces joint pain

So far, the quality of evidence is low as to whether dietary collagen can help soothe creaky knees and hips, Dr. Linsenmeyer says.

A 2018 meta-analysis published in International Orthopaedics looked at five studies comprising 519 volunteers and determined that collagen was associated with “significant” improvements in osteoarthritis symptoms. But Dr. Lisenmeyer notes that 519 volunteers are considered a small pool, and the studies looked at various formulations of collagen for different periods of time (anywhere from 10 to 48 weeks). So the jury’s out on what might work best—or whether any effects last for more than a few months.

On that matter, a 2017 systematic review published in the British Journal of Sports Medicine looked at the results of 69 studies investigating 20 oral supplements and their effects on pain reduction for patients with osteoarthritis of the hand, hip, or knee. Researchers found that while some types of collagen seemed to reduce pain in the short term, they showed no clinical effect in long-term follow-up analysis. (None of the supplements did, for what it’s worth.)

“The reality is that results are mixed,” Dr. Linsenmeyer says. “When this is the case, typically the scientific community doesn’t broadly recommend use of an intervention.”

Claim 2: Collagen can make skin look “younger”

Some fans joke that collagen works like “edible Botox,” smoothing out wrinkles and plumping up mature skin. But the science, despite hinting at some promise, is far from definitive.

A May 2020 review in the Journal of Cosmetic Dermatology looked at 10 randomized controlled trials that lasted between 8 and 12 weeks. Almost all found an association between supplemental collagen and improvements in skin health. Another review, published in the Journal of Drugs in Dermatology, looked at 11 studies encompassing 805 patients and found that oral collagen increased skin elasticity, hydration, and dermal collagen density. Researchers reported no adverse events, a good sign for general safety.

It’s still too soon to draw hard conclusions from those findings, however. Dr. Linsenmeyer notes that the studies cited above all used small sample sizes and were not consistent in the forms of collagen they evaluated.

Claim 3: Collagen can speed weight loss

No single food or ingredient has special powers to melt pounds. That being said, collagen is a protein, which can support healthy weight management in a general sense. “Dietary protein helps us to feel full,” Dr. Linsenmeyer explains. In terms of satisfying appetite, there’s insufficient evidence to support the theory that collagen is superior to other proteins, she says.

A 2009 study of 24 volunteers published in Clinical Nutrition compared collagen with other protein types to explore differences in subsequent calorie intake. Subjects who ate a breakfast that included collagen (in the form of gelatin) ate 20% fewer calories at lunch than subjects whose morning protein was casein, whey, or soy.

A paper published in The Journal of Nutrition the same year supports those findings: When 23 people were instructed to follow various diets over 36 hours, those who got 10% of their calories from gelatin reported feeling 44% less hungry than subjects who got 10% of their calories from casein.

Still, Dr. Lisenmeyer notes, these studies were small and of limited scope, with no evaluation of actual body weight over time.

How to support the body’s collagen production

Given that consuming more collagen doesn’t necessarily impart an equal-size collagen boost in our connective tissue, most of us would do better to focus on supporting our body’s natural collagen production, Dr. Linsemeyer says. Here, she outlines the nutrients the body uses to produce collagen:

  • Protein: Dr. Lisenmeyer recommends opting for an array of protein sources, including meat, poultry, seafood, tofu, tempeh, eggs, nuts, pulses, and dairy. This will provide the diversity of amino acids your body needs to synthesize its own proteins, including collagen.
  • Vitamin C: This nutrient is found in most fruits and vegetables, especially bell peppers, citrus fruits, cantaloupe, strawberries, blueberries, and broccoli.
  • Zinc: You’ll find it in shellfish, beef, pork, poultry, and beans.
  • Sulphur: Overlapping with zinc, sulphur is found in beef, poultry, and beans, plus fish and eggs.

Lifestyle measures may make a positive difference, as well. Research suggests that you may be able to reduce the breakdown of collagen in the body by consuming less added sugar, being mindful of sun exposure, and avoiding smoking.

The upshot: Can dietary collagen improve health?

The jury is still out on whether collagen supplements, as well as foods containing collagen, can offset age-related declines in the body’s collagen production. Most studies seeking to explore potential health benefits have been limited in size and scope, and findings have been mixed. Eating a variety of whole foods can help provide the nutrients your body needs to produce collagen. While collagen supplements are generally considered safe, check with your doctor if you’re thinking about trying one.

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Leslie Pepper is a freelance health and lifestyle journalist in New York.