Collagen is a plentiful protein and vital component of muscles, organs, skin, tendons and connective tissue, such as cartilage. Cartilage, found in the knee and throughout the body, acts as shock-absorbing padding between bones, protecting joints and facilitating movement. With age, collagen production slows and cartilage degenerates, often resulting in pain, stiffness and inflammation that can lead to osteoarthritis. Food alone can't replace collagen in your knee joints, but certain nutrients can help preserve the collagen you have and optimize your body's own collagen synthesis.
Collagen and Protein Connection
Collagen is the main protein in cartilage, ligaments and bone. Your body makes collagen by combining amino acids. Although your body can produce some amino acids on its own, others need to be derived from food. Focus on eating foods that are complete proteins, meaning that they contain all nine essential amino acids that the body can't make. These foods include red meat, poultry, fish, quinoa, soybeans, eggs, cheese, milk and yogurt.
One food trend thought to support collagen rejuvenation is bone broth, made by simmering beef, chicken or fish bones, drawing out the collagen and leaving a liquid for drinking or use in cooking. Although bone broth contains bone marrow and collagen, the Center for Nutrition Studies states that there's no scientific evidence supporting that it has more effect on joints than other protein-rich food.
Vitamin C for Preservation
Your body also needs adequate vitamin C for the synthesis of collagen. Vitamin C interacts with the amino acids in cells by adding oxygen and hydrogen, stimulating collagen production. In addition, vitamin C has antioxidant properties to protect against destruction from free radicals. Antioxidants may not regenerate collagen, but they'll help preserve the collagen you have. Vitamin C also helps convert proline to hydroxyproline, an amino acid found in connective tissue, specifically collagen, according to "Molecular Cell Biology."
Because vitamin C is water soluble, you need to consume foods rich in vitamin C every day just to reach the recommended daily value of 75 to 90 milligrams. Foods that contain the most vitamin C include kiwi, guavas, bell peppers, Brussels sprouts, strawberries, oranges, tomatoes, green chilies, papayas, broccoli, kale and snow peas.
Read More: How Much Vitamin C Can the Body Absorb?
Magnesium for Healing
All components of connective tissue, including collagen, depend on magnesium. Approximately half of the magnesium in your body is concentrated in your bones, according to the San Diego Center for Health. Magnesium helps modulate the synthesis and healing of collagen connective tissue and is necessary for the conversion of vitamin D for absorption of calcium in bone matrix. Magnesium regulates the protein compound proteoglycan, which strengthens connective tissue, and glycoprotein, involved in the healing of connective tissue.
The best food sources of magnesium are dark leafy greens, seeds, fish, whole grains, nuts, bananas, avocados, dark chocolate, beans, yogurt and bananas. Try to get at least the recommended daily value for magnesium — 320 milligrams for women and 420 milligrams for men.
Read More: The Benefits of the Magnesium Mineral
Although it's always best to get your nutrients naturally from a well-balanced diet, collagen supplements are always an option — available in several different forms, including gelatin, hydrolyzed and undenatured. Some supplements, such as collagen peptides, are promoted as beneficial for arthritis by helping your bones and joints. Gelatin and hydrolyzed collagen supplements break down the amino acids to make them more easily digested and absorbed. In powdered form, collagen supplements can be added to smoothies or other beverages, or added to baked goods.
Read More: Exercises for Damaged Knee Cartilage