Curious About Collagen
Note to readers: You can listen to this article by clicking on the voiceover recording above.
Earlier this year, two women friends in my dance class asked me about collagen. They approached me separately, about two weeks apart, both for their own reasons – we are, after all, an aging dance community – a diverse group held together by a shared love of movement. In the sweaty flush that follows the class, many ideas are exchanged.
One friend felt her skin had become weak and friable, and bruised easily. The other had noticed a weakening of her connective tissue, affecting her ankles and spine and making her prone to injuries. Could lack of collagen be the reason?
Like them, I already knew collagen is crucial for healthy skin and hair, resilient connective tissue, durable cartilage, strong bones, and sturdy nails. As the most prevalent protein in the body, collagen is everywhere, providing the cellular scaffolding of your body’s blood vessels, tissues, and organs – including the largest organ, your skin. Collagen is what makes these structures strong and flexible. It supports skin hydration and elasticity, and also plays a role in athletic performance. It provides an essential protein for the formation of keratin, the structural component of hair. And it is found in dentin in teeth, and even the viscous solution of the eye.
Clearly, this protein is of paramount importance in maintaining our physical integrity. Good collagen enables us to run, walk, stand, sit, swim, dance, or do just about anything physical. Without collagen, we could not lift a child, play a guitar or piano, pivot a skateboard, swing a tennis racket, or climb a mountain. We would literally fall apart, like a frameless house. Collagen degradation is responsible for wrinkles, and may set the stage for ankle sprains, rotator cuff tears, stress fractures, spinal weakness, broken hips, or trigger finger, to name just a few. If you want your skin to be moist and resilient and your muscles and joints to serve you well, they need the raw materials to do it. Let’s take a look at the types of collagen our bodies need.
Types of Collagen
Collagen is a fibrous structural protein. It consists of amino acids – the building blocks of protein. Short chains of amino acids are known as peptides, which then form triple helixes or polypeptides that resemble a microscopic rope. Hydrogen bonds and cross-links allow for tight coiling that is strong and resilient, forming fibrils, which are like the fine filaments of a tapestry. Fibrils then bundle together to form thick fibers. Individual fibers are stacked in a staggered formation to add more stability. Collagen fibers possess great tensile strength, enabling them to stretch and recover in response to movement. Patterns of folding and linking vary from tissue to tissue, creating densely-packed fibers in tendons and looser arrangements in skin.
There are at least 28 known types of collagen. The main ones we need to consider are types 1, 2, 3, and 4.
Type 1 collagen is the most prevalent in the human body, found in up to 90% of our tissues, including skin, tendons, ligaments, bone, dentin, nails, hair, cornea, and blood vessel walls. When consumed as bovine or marine collagen, it is most beneficial to skin, hair, and nails.
Type 2 collagen is found in cartilage, joints, intervertebral discs, the gut lining, and the eye. This type of collagen provides resistance to pressure.
Type 3 collagen is found in skin, blood vessels, and hollow organs (intestines, uterus, bladder). It provides elasticity, often paired with Type 1, and also helps your body produce its own collagen by acting as signaling proteins. These remarkable proteins stimulate the activity of fibroblasts that build new collagen, and increase the density of new fibers.
Type 4 collagen makes up “basement membranes” – the fine structural mesh that underlies the mucosal lining of the gut, as well as the kidney glomeruli, lung alveoli, all epithelial cells (that form protective barriers on the outer surfaces of the body and internal organs) and endothelial cells (that line the inner surfaces of blood and lymphatic vessels).
Bovine collagen contains types 1 and 3.
Chicken is rich in type 2 collagen.
Fish skin and bones contains types 1 and 3 collagen.
Porcine collagen contains types 1 and 3, as well as trace amounts of types 4, 5, and 6.
Collagen’s Role Your Body
Collagen is found in approximately 90% of our body tissues – bones, joints, tendons, ligaments, cartilage, hair, skin, nails, fascia, interstitial tissue, dentin, arterial walls, the cornea and vitreous humor of the eye, and the lining of the gut. Clearly, in order to function optimally, every system in the body requires collagen’s strength, elasticity, scaffolding, and anchoring. Collagen is the building blocks of your skin and connective tissue. In addition, its lesser-known but equally important spheres of influence include:
Gut Health
Most interesting and overlooked is collagen’s role in the gut, for it not only makes up the sublayer of the delicate mucosal lining of the intestines, but also strengthens and repairs that lining by way of glycine and proline, two important amino acids found in collagen. The integrity of this barrier is crucial for keeping toxins and other illicit substances out of the bloodstream that may trigger inflammation or cause an autoimmune reaction, especially in the skin and joints. Thus, collagen may also strengthen these tissues by helping to heal and seal the gut. Intestinal permeability or “leaky gut” affects every aspect of health, as most chronic health conditions (including chronic good health) come from the gut. Crohn’s disease, ulcerative colitis, IBS, and acid reflux may all be eased by glycine. Collagen also contains glutamine, which further soothes the gut lining, and may also stimulate gastric juices.1
Bone strength
Collagen forms about one third of the physical matrix of bones, into which minerals are deposited, and also stimulates the activity of both osteoblasts (bone-building cells) and chondrocytes (cartilage-building cells).
Relaxation and sleep
Glycine acts as an inhibitory neurotransmitter in the brain. This amicable amino acid can cross the blood-brain barrier, where its calming effect promotes relaxation and sleep, and may even increase serotonin levels.
Amino acid balance
Glycine counterbalances the effects of methionine, another amino acid which may be too dominant in a heavily meat-based diet, and is known to be inflammatory if consumed in excess.
Blood clotting
Platelets stick to the collagen that is exposed when a blood vessel wall is damaged. Without collagen, the clotting process may not function properly, resulting in dangerous internal bleeding.
Physical activity
Collagen is both necessary for and stimulated in response to exercise. Movement is a message that tells your body it needs strong bones and connective tissue. Over time, the physical strain of exercise directly upregulates collagen gene expression. Resistance training (weight lifting, resistance bands, etc), cyclic mechanical loading (walking, cycling, swimming), and aerobic exercise all stimulate different types and phases of collagen growth, as well as post-exercise muscle recovery and repair. Consuming collagen together with a vitamin C-rich food supports this process.
Cardiovascular health
Some studies have shown cardiovascular benefits from collagen supplementation, with improvements in LDL markers and systolic blood pressure.2 This is probably due to the amino acid proline, which may support arterial resilience and prevent atherosclerosis.3 More research is needed.
Dietary Sources of Collagen
Collagen is animal protein and cannot be derived from plants. But since it is taken mostly from the skins of fish and hides of cows, the animals are not being slaughtered for that purpose – rather, it's a way of making full use of the animal.
Bone broth (slow-cooked bones, joints, tendons, and cartilage) is a superior source of collagen, especially if the animals are raised on a healthy diet of pastured plants. Bone broth made from chicken or lamb bones that have already been cooked, for example as roasted chicken or lamb chops, is another way to make full use of the animal. Add a few tablespoons of apple cider vinegar to draw out the minerals. Besides providing collagen, bone broth contains highly absorbable calcium, magnesium, silicon, sulfur, and phosphorus, as well as two familiar proteoglycans – glucosamine and chondroitin sulfate – long-chain polysaccharides (sugars) attached to proteins. The word “chondroitin” is related to “chondrocytes” – cells that build cartilage by attracting water, thus creating cushioning and providing resilience and shock absorption. Proteoglycans also act as signaling molecules, and help to regulate enzymes that control collagen breakdown. All this in a bowl of soup!
Other good sources of collagen include:
• Skin-on poultry (chicken/turkey/duck/pheasant/cornish game hen skin)
• Fish skin and bones
• Pork skin (rinds)
• Beef connective tissue (oxtail, shank, brisket)
• Gelatin (from animal collagen, used in jellies, gummies, and soups). Gelatin was once used as a significant source of collagen. With the rise of hydrolyzed collagen powders (which breaks the peptides down into more absorbable particles), gelatin has been replaced by these more user-friendly products. See below for more about collagen supplements.
• Eggshell membranes – The inner membranes of eggshells also contain collagen, but not nearly enough is found in a reasonable daily portion – you would have to consume over fifty eggshells each day! Still, I always peel the membranes from the shells and cook them with my eggs. Duck eggs have much thicker membranes, which may be cut up with kitchen scissors.
Collagen Supplements
Do collagen supplements work? For skin hydration and elasticity, studies says yes.4 For joint health, I can speak from my own experience: three months of taking a teaspoon a day of marine collagen (approximately 3-5g) led to significant improvement in my lower back, which has lacked stability and significantly limited my activities for the past three years. Despite exercising regularly and eating a diet rich in pasture-raised animal protein, my body was simply not synthesizing enough collagen. Why? Because after menopause, both nutrient absorption and protein synthesis slow down. I try to get my nutrients from food and nourishing herbal infusions, but I simply cannot make or buy enough bone broth to supply my body’s needs for collagen, especially in summer. The day came when my curiosity overcame my resistance, and I saw the value in trying collagen as a supplement. This has enabled me to not only avoid surgery, but resume my most joyful and strenuous activities – such as walking my dog, stacking firewood, and enjoying the above-mentioned dance class. Functional medicine physician Chris Kresser also shared his story of recovery from a severe back injury with the use of 20g of collagen each day.5 He’s happily skiing again. Collagen can be a game changer!
If you purchase a collagen supplement, be sure to look for hydrolyzed collagen peptides. These dissolve easily in any beverage, and are readily absorbed.
Supporting Collagen Production
To help your body synthesize collagen, the following nutrients are necessary:
Vitamin C – this is an essential cofactor for collagen synthesis (preferably not from supplements – instead, try including citrus fruit, peppers, kiwi, broccoli, apples, leafy greens, and rosehips or hibiscus tea in your diet).
Copper and manganese both support collagen cross-linking, an integral step in building its final structure. These minerals are derived from whole nuts, seeds, and grains.
Sulfur compounds from garlic, onions, and cruciferous vegetables help in connective tissue repair.
Zinc also plays a role in collagen synthesis. Foods rich in zinc include animal products like shellfish (especially oysters), red meat, and poultry, as well as plant-based foods such as nuts, seeds, and legumes. The zinc in animal foods is more easily absorbed than that found in plant-based sources, which contain nutrient-blocking lectins and phytates. This fat-soluble mineral is best absorbed together with fatty foods.
Silicon is another important nutrient that supports the production of collagen. Horsetail is an excellent source of silicon, which is also needed for strong bones. Horsetail is a common springtime roadside weed that may be gathered while young. It resembles a baby pine seedling. If you fill a jar with fresh plant material and then fill the jar again with apple cider vinegar, after 6 weeks you'll have an excellent horsetail extract to sprinkle on salads.
Nourishing herbal infusions of nettles, oat straw, and red clover contain minerals, vitamins, amino acid precursors, and other cofactors that support the production of collagen.
Preventing Collagen Breakdown
High-heat cooking (broiling, frying, grilling, smoking, air-frying, and roasting) damages collagen by way of glycation – the fusing together of proteins and sugars at high heat. The sugar sticking to the protein causes the proteins to fold abnormally, causing cross-fibers and abnormal formation of collagen. This is a major source of wrinkles. Low, slow, wet cooking techniques are best. Liquid marination prior to high-heat cooking may also reduce glycation. Use plenty of spices to add antioxidants, such as rosemary, thyme, turmeric, garlic, and basil.
Sugar and starch also damage collagen by causing free radical damage via oxidative stress (see my article It's All About Insulin for more on this subject). Reducing or eliminating refined carbohydrates from your diet is the best way to prevent this. Eating plenty of antioxidants (green tea, berries, dark chocolate, mushrooms, and herbs) can help repair the damage of oxidative stress. (See my article Activate Your Antioxidants. Both articles have voiceover recordings.)
Green tea is high in EGCG (epigallocatechin gallate) — a powerful polyphenol that protects against UV-induced collagen breakdown, and enhances skin elasticity and moisture retention, especially when consumed regularly.
Pomegranates and organic strawberries contain ellagic acid, which stabilizes collagen fibers and protects it from degradation.6 Lycopene, found in cooked tomatoes, is another antioxidant that helps prevent collagen breakdown.
As a gentle nervine, oat straw infusion helps to lower cortisol, the stress hormone that inhibits collagen repair. Red clover infusion contains isoflavones (phytoestrogens), which may help protect collagen from breakdown in post-menopausal women.
Two months after my friends asked me about collagen, one of them happily reported that her skin had much improved. Adding grass-fed collagen to her diet was the only change she had made, and she was seeing a real difference. As for the other friend, she is vegetarian, and eats only a modest amount of animal protein – but a recent diagnosis of a ruptured disc in her spine is motivating her to consider new options. These experiences as well as my own are all good examples of how nutrient deficiencies manifest differently in each individual. The weakening of body structures takes place silently as we go about our lives, setting the stage for future breakdown. The unwelcome outcome may appear suddenly, but its upstream causes began long ago.
With the right nutrition and judicious use of supplements, we can change the trajectory of our health as we age. Consistency is key in building healthy tissues, as well as diversity – for strong collagen, we need not just one convenient product but a wide range of animal proteins, as well as antioxidant- and mineral-rich plants. All are necessary to provide the best building blocks for a strong and resilient body.
Day by day, you can create the outcome that serves your lifestyle and goals. Understanding the cause and effect of nutrition enables you to make choices and establish habits that allow you to pursue your most desired activities. Patience and persistence make it possible – just like those slow-simmering bone broths I’ll be cooking on my wood stove this winter. As the season turns toward autumn, I’m looking forward to it.
To your good health –
Yael Bernhard
Certified Integrative Health & Nutrition Coach
Yael Bernhard is a writer, illustrator, book designer and fine art painter with a lifelong passion for nutrition and herbal medicine. She was certified by Duke University as an Integrative Health Coach in 2021 and by Cornell University in Nutrition & Healthy Living in 2022. For information about private health coaching or nutrition programs for schools, please respond directly to this newsletter, or email dyaelbernhard@protonmail.com. Visit her online gallery of illustration, fine art, and children’s books here.
Information in this newsletter is provided for educational – and inspirational – purposes only.
Have you seen my other Substack, Image of the Week? Check it out here, and learn about my illustrations and fine art paintings, and the stories and creative process behind them.
Axe, Dr. Joshua, Eat Dirt: Why Leaky Gut May Be the Root Cause of Your Health Problems, Harper Wave, 2016, pp. 175-178.
https://pubmed.ncbi.nlm.nih.gov/35658958/
https://pmc.ncbi.nlm.nih.gov/articles/PMC5429168/
Apple podcast: rhr-beauty-from-within-why-radiant-skin-hair-and/id372257397?i=1000720688580
Apple podcast: /rhr-everything-you-need-to-know-about-collagen/id372257397?i=1000703563440
https://pubmed.ncbi.nlm.nih.gov/20113347/