Collagen is a protein that connects tissues throughout our entire body. In skin, bones, tendons and ligaments, collagen proteins are rigid and resist stretching. When we lose collagen with age, our skin may sag and our joints may feel achy.

Collagen supplements may help (see our best collagen powder picks here). But they can be pricey. So what can you do to maintain the collagen you have, and build collagen from food?

It’s important to preserve the collagen you have in joint tendons and ligaments by doing some weight training. To preserve collagen in your skin, stay out of the sun and when outside, wear sunscreen and sun-protective clothes. The sun’s UV rays cause oxidation in cells, which can slow the body’s natural production of collagen and destroy collagen in the skin. Oxidation is also caused by alcohol use and smoking.

The body also makes collagen through nutrients found in a healthful diet. Collagen is made up primarily of amino acids glycine, proline and hydroxyproline. In order for the body to synthesize collagen, it also needs nutrients zinc, copper, vitamin C and protein-rich foods containing a variety of amino acids. While research in this area is limited, eating foods that contain many of these nutrients makes sense to maintain collagen levels in the body naturally. Here are foods that can help to stop collagen loss.

Bone broth is one of the few foods that contains natural collagen. It is made by cooking and drawing the collagen out of beef, chicken or fish bones. Bone broth also contains hyaluronic acid; this component may help maintain skin elasticity by restoring skin hydration. Bone broth is simple to make, it just takes time. Or, when making long-cook stew or soup recipes, use cuts of ‘bone-in’ beef, pork or chicken; some of the collagen will be drawn into the soup. (You know your dish contains collagen when the broth solidifies into a gelatin-like liquid after the soup/stew has been refrigerated overnight.) Try Andy Liang’s Chinese Herbal Chicken Soup if you need somewhere to start.

Yes, really, eat the skin! Fish skin is a source of collagen. Some people fight for the crispy skin. Others, do not. If a grilled skin-on salmon or trout fillet is not for you, think about tinned fishes. Tinned sardines and mackerel usually contain skin; mash them like you would a can of tuna and make a sandwich or dip. Use fish skin and bones to make fish broth. For those that can get on the whole grilled fish train, start with Widza Gustin’s Epis-Marinated Grilled Red Snapper.

Remember, collagen is connective tissue. So there isn’t much collagen in chicken muscle meat, but we often eat chicken off the bone: think skin-on drumsticks, thighs and wings with the wing tip. It’s the skin, joint material and cartilage that contains the most collagen. Opt for grilling or roasting those drumsticks and wings instead of the not-so-healthful frying. Chicken meat from any cut is rich in protein and thus the amino acid building blocks of collagen.

Beef is a rich source of zinc and several amino acids found in collagen. Most bone-in cuts also contain connective cartilage which is a source of collagen. Beef liver is one of the few foods containing hyaluronic acid for restoring skin moisturize. It also contains copper, essential for synthesizing collagen.

Eggs are a source of the amino acid proline needed for the production of collagen. Proline is also one of the amino acids that helps keep skin moist – a key way to help prevent collagen loss. Eggs contain 18 of the 20 amino acids that can be used by the body to build more collagen.

Dairy foods like milk and yogurt contain protein and thus amino acids for collagen formation. They also contain small amounts of zinc and copper.

Plant foods do not contain collagen. But many plants are sources of vitamin C, which helps synthesize and stabilize the collagen we have. Vitamin C is also an antioxidant to help combat oxidation from the sun and other stressors. Eat a variety of fruit including oranges, grapefruit, kiwi, tomatoes, strawberries, mangoes and papaya. Vitamin-C containing vegetables include white potatoes, bell peppers, cabbage, Brussels sprouts and other leafy greens.

Most nuts and seeds contain copper and zinc which the body needs for collagen production. Nuts that are a good source of copper include almonds, Brazil nuts, cashews and walnuts. Sesame seeds, sunflower seeds and pumpkin seeds all contain copper and zinc. In addition, these protein-containing plant foods contribute some of the amino acids needed for collagen synthesis. (However, it’s not possible to get all the amino acids for collagen production from vegan sources of protein.) Almonds in particular were linked with skin health when researchers that found that women who ate two servings of almonds daily for six months had a decreased appearance of wrinkles and better skin pigmentation.

Green teas and ginger teas are packed with antioxidant polyphenols. These potent plant chemicals can help prevent oxidation and the loss of collagen from UV rays in skin and other inflammatory stressors that cause the break-down of collagen in skin, tendons and ligaments. Ginger contains gingerol, a potent plant phenol that can tamp down on inflammation. Green tea contains catechins which are also anti-inflammatory compounds. In addition, these teas contribute hydration for the synthesizing of collagen and for maintaining healthy skin and joint cells.