What foods are rich in glycine?

Glycine-Rich Foods

The richest dietary sources of glycine are animal-derived proteins, particularly gelatin, bone broth, and collagen-containing foods, followed by meat, poultry, fish, and dairy products. 1

Primary Glycine Sources

Highest Glycine Content (Animal Products)

• Gelatin provides the highest amount of glycine (10-35% of total protein), making it the single best dietary source 1
• Bone broth and collagen supplements are exceptionally rich in glycine due to their high collagen content 1
• Feather meal, fish meal, meat and bone meal, and poultry byproducts contain 10-35% glycine of total protein 1

Excellent Glycine Sources (Protein-Rich Foods)

• Lean meats, poultry, and fish should be consumed 1-3 servings daily (alternating), with each serving providing 1 oz cooked meat 2
• Fish and shellfish (2 or more servings per week, 3.5 oz per serving) are rich protein sources containing glycine 2
• Eggs (1-3 servings daily, alternating with other proteins) provide glycine as part of complete protein 2
• Dairy products (2-3 servings daily) including milk, yogurt, and cheese contain glycine 2

Good Glycine Sources (Plant-Based)

• Legumes (beans, lentils, split peas) consumed 1-3 times daily provide glycine along with other amino acids 2
• Nuts and seeds (4 servings per week, 1 oz per serving) contain moderate amounts of glycine 2
• Peanut meal and cottonseed meal have notable arginine content but lower glycine compared to animal sources 1

Clinical Context and Supplementation Considerations

Glycine Insufficiency

• Endogenous glycine synthesis (approximately 3 g/day) plus typical dietary intake (1.5-3.0 g/day) may fall short of metabolic needs by about 10 g/day in a 70 kg adult, particularly for collagen synthesis 3
• Glycine is considered a semi-essential amino acid because synthesis from serine cannot meet total body demands, especially for collagen production 3

Therapeutic Benefits

• Glycine supplementation has demonstrated protective effects in cardiovascular diseases, inflammatory conditions, obesity, cancer, and diabetes 4
• Glycine acts as a cell-protecting antioxidant and reduces cytokine production in inflammatory diseases 5
• Glycine may enhance peak power output, reduce lactic acid accumulation, and improve sleep quality and recovery in athletes 6

Practical Dietary Recommendations

• Prioritize high-quality protein foods (PDCAAS or DIAAS close to 100) including meat, poultry, fish, dairy, eggs, beans, and nuts at two or more meals daily 2
• Include bone broth or gelatin-based foods regularly to maximize glycine intake 1
• Consume 0.4 g protein/kg body weight per meal to stimulate muscle protein synthesis, which can be achieved through the protein sources listed above 2

Safety Considerations

• High doses exceeding 500 mg/kg body mass could induce cytotoxic effects and contribute to acute glutamate toxicity 6
• Adequate protein intake from varied sources is essential, as plant-based proteins alone (corn, soybean) have lower glycine content compared to animal sources 1