What is in foods that contain collagen?
Foods containing collagen provide proteins, amino acids, peptides and minerals. In animal sources this specifically includes the structural protein collagen, and as a supplement, hydrolysed collagen is the most studied form for skin health.
Foods that naturally contain collagen consist largely of proteins and amino acids, supplemented by inorganic minerals. Collagen itself is a protein found in animal products such as tendons, cartilage and connective tissue. The collagen in those products can be broken down into smaller protein fragments called peptides, which are biologically active.
Snails are a lesser-known example of collagen-rich food. Snail meat contains high-quality proteins, essential amino acids (amino acids your body cannot make on its own), minerals and omega-3 fatty acids. Snail slime also contains glycoproteins (proteins with a sugar molecule attached) and hyaluronic acid, a substance the body uses to keep connective tissue hydrated.
Collagen in dietary supplements is extracted from animal sources such as fish and cattle, but also from milk and sometimes plants. Manufacturers break the collagen into small fragments (at that point it is called hydrolysed collagen or collagen peptides), making it easier for the body to absorb. These peptides have properties that help reduce swelling and irritation, and are being studied for their effects on joints and bones.
Collagen is not a complete protein for building muscle. Taking 15 grams of collagen peptides per day stimulates collagen production, but for building muscle tissue other proteins work considerably better. If you want to use collagen for your skin, take 2.5 to 5 grams of hydrolysed collagen per day for at least 8 to 12 weeks. Checking the label? Look for 'collagen peptides' or 'hydrolyzed collagen'; whether it comes from fish, cattle or pigs does not matter.
This answer is based on four reviews combining many studies. The descriptions of the composition of collagen-rich foods are fairly consistent across those sources, but the studies mainly describe what is in foods (descriptive), not what their effects are. The researchers draw no firm conclusions about consuming collagen-rich whole foods; studies on effects focus almost exclusively on concentrated supplements.
Which peptides occur naturally in food?
Almost all protein-rich foods, from legumes to fish and dairy, naturally contain peptides that are released during digestion and can be biologically active. Studies show promising effects, but how much of that actually occurs in people has been only limitedly researched.
Are there dietary patterns that have been proven to reduce your risk of cancer?
The Mediterranean diet and sufficient vegetables and fruit are consistently associated with a lower cancer risk, although the effects are modest and the findings are associations. The evidence is strongest for colorectal cancer; ideally combine diet with other healthy habits for the greatest effect.
Which fermented foods are the healthiest?
Yoghurt has the strongest support: regular consumption is linked to a lower risk of diabetes and heart and vascular disease. Cheese follows at a reasonable distance; for kefir, the evidence from studies in people remains limited.
Is eating organic food really healthier?
Eating organic demonstrably leads to lower pesticide exposure and less contact with antibiotic-resistant bacteria through meat. Whether this translates into less disease in the long run remains unclear.
Which type of collagen is best to take?
For the skin, hydrolysed collagen peptides (2.5 to 5 grams per day for at least 8 to 12 weeks) are the best-supported option. For knee pain, you can try UC-II (40 mg per day) or hydrolysed collagen (10 grams per day) for six months, but the only independent study found no effect.
How much collagen per day is worthwhile?
For the skin, 2.5 to 5 grams of hydrolysed collagen per day demonstrably works after at least 8 to 12 weeks: pay attention to the active peptide content, not just the grams on the label. For knee complaints, a completely different product has been studied, so look carefully at which form you buy.