The undisputed champion: Gelatin and collagen powder
While glycine is found in many protein-rich foods, the highest concentration is found in products derived from collagen, the most abundant protein in the body.
Why gelatin is so rich in glycine
Gelatin is produced by boiling animal bones, cartilage, and other connective tissues, which are naturally loaded with collagen. This process breaks down the collagen into gelatin, a highly concentrated source of the amino acids that make up collagen, with glycine being the most prominent. A single 100-gram serving of dry gelatin powder can contain over 19 grams of glycine.
Collagen powder, which is essentially hydrolyzed collagen, offers a similar and highly digestible concentration of glycine. The processing breaks down the collagen into smaller peptides, which are more easily absorbed by the body. This makes supplements an extremely efficient way to boost your glycine intake.
Top animal-based sources of glycine
Beyond gelatin and supplements, several animal-based foods offer a significant dose of glycine, particularly those that include bones, skin, and connective tissue.
- Pork Skin and Pork Hocks: Pork skin snacks and pickled hocks are surprisingly high in glycine due to their connective tissue content. Cooking cuts like pork hocks low and slow helps extract the glycine-rich collagen.
- Bone Broth: Made by simmering animal bones and connective tissue for extended periods, bone broth is a flavorful source of glycine. While less concentrated than pure gelatin, it is a practical and savory way to consume more glycine.
- Poultry Skin and Connective Tissue: Chicken and turkey skin, often discarded, are packed with collagen. A 100-gram serving of roasted chicken skin can provide over 3 grams of glycine.
- Tougher Cuts of Meat: Leaner muscle meats contain less glycine than the connective tissues. However, tougher cuts of beef and lamb, such as brisket or lamb shoulder, have more connective tissue and thus more glycine than a lean cut like steak.
- Dried Fish: Certain dried fish products, like dried whitefish or smelt, are also notable sources of glycine.
- Eggs: Egg whites contain a solid amount of glycine, though not as much as collagen-rich products.
Excellent plant-based sources
While animal sources are the most concentrated, several plant-based foods can help boost your overall glycine intake.
- Seeds: Pumpkin seeds, chia seeds, and sunflower seed flour are among the best plant-based sources. They can be easily added to salads, smoothies, or yogurt.
- Legumes: Soybeans, lentils, and other beans contain a decent amount of glycine, along with other essential nutrients and fiber. Fermented soy products like tempeh also contribute.
- Nut Butters and Flours: Defatted peanut flour and sesame flour offer a concentrated source of glycine from plant-based foods.
- Vegetables: While lower in concentration, vegetables like spinach and kale contribute to your daily intake.
- Soy Protein Isolate: Concentrated soy products like soy protein isolate can also be a source of glycine.
Health benefits of a glycine-rich diet
Adequate glycine intake supports numerous bodily functions.
- Collagen Production: Glycine is a primary component of collagen, which is crucial for the health of your skin, bones, tendons, and ligaments. Increased collagen synthesis can improve skin elasticity and joint health.
- Antioxidant Support: Your body uses glycine to produce glutathione, a powerful antioxidant that protects cells from damage.
- Improved Sleep Quality: Studies suggest that taking glycine before bed can improve sleep quality, help you fall asleep faster, and reduce daytime fatigue.
- Muscle Growth and Repair: Glycine helps stimulate the secretion of growth hormone and aids in the synthesis of creatine, which supports muscle growth and energy production.
- Cardiovascular Health: Higher circulating levels of glycine have been associated with a reduced risk of cardiovascular disease.
Comparison table of glycine-rich foods
| Food Source | Glycine Content (grams per 100g) | Notes |
|---|---|---|
| Dry Gelatin Powder | ~19.1 | Highest concentration, from animal connective tissue |
| Pork Skin Snacks | ~11.9 | Very high concentration, rich in collagen |
| Chicken Skin, roasted | ~3.3 | High content due to collagen |
| Defatted Sesame Flour | ~3.4 | A concentrated plant-based source |
| Dried Egg Whites | ~2.8 | High-protein source, significant glycine |
| Lamb, lean | ~1.8 | Good source, especially from tougher cuts |
| Pumpkin Seeds | ~1.8 | One of the best plant-based sources |
| Bone Broth (per cup) | ~1.7 | Practical for daily intake, but less concentrated |
| Chia Seeds | ~1.6 | Excellent plant-based source of protein and fiber |
| Soybeans | ~1.6 | A versatile and effective plant-based source |
How to incorporate more glycine into your diet
- Add gelatin or collagen powder to your coffee, tea, or protein shakes. It dissolves easily and often has a neutral or slightly sweet taste.
- Make your own bone broth using bones, skin, and connective tissues from chicken, beef, or pork. You can sip it throughout the day or use it as a base for soups and stews.
- Include animal skins in your cooking. Roast chicken with the skin on or use pork skin to make a crispy side dish.
- Sprinkle seeds like pumpkin or chia onto your salads, oatmeal, or yogurt for an easy glycine boost.
- Choose legumes and soy products as your main protein source for vegetarian options.
- Cook with tougher cuts of meat that contain more connective tissue, and consider incorporating organ meats like liver, which also contain beneficial amino acids.
Conclusion: Making informed choices for glycine intake
For those seeking the absolute highest concentration, gelatin and collagen powder are the foods with the most glycine, primarily due to their direct derivation from collagen. However, a range of natural whole foods, both from animal sources like bone broth and chicken skin, and plant sources like pumpkin seeds and soybeans, offer excellent ways to increase your dietary intake. By incorporating these foods, you can support your body’s collagen production, antioxidant defenses, and overall wellness. Whether you opt for a supplement or a diet rich in these natural sources, prioritizing glycine can lead to noticeable health benefits. Learn more about the specific functions of glycine in the body and its interaction with other amino acids here: Healthline: Methionine vs. Glycine.
