HealthyRetired · Food and Healthy Aging
Collagen appears on everything from beauty creams to expensive powders. The advertising can make it sound as though ageing is simply a shortage of something we should buy. But collagen is already part of us—and our body knows how to make it.
For those of us who eat mainly plant foods, that is useful news: we do not have to eat animal collagen to produce our own.
What is collagen?
Collagen is a family of structural proteins. Its fibres help give our tissues strength and support. Think of it as part of the body's scaffolding, rather than a vitamin or a hormone.
Different types serve different purposes. Type I is abundant in skin, tendons and bone; type II is important in cartilage; type III supports tissues including skin and blood vessels. In bone, collagen forms a flexible framework that is strengthened by minerals. Strong bones need both the framework and the minerals.
Collagen also contributes to wound healing. It is much more than something that keeps our face looking young.
What changes as we age?
Ageing changes how collagen is made, organised and repaired. Skin can become thinner, while tendons and other connective tissues may become less resilient. Sun damage and smoking can add to these changes.
There is no birthday on which collagen production suddenly stops. Nor can every wrinkle or aching joint be explained by a collagen shortage. Joint health, for example, also involves muscles, inflammation, previous injuries and the loads we put through our bodies.
The aim is to support normal maintenance, rather than promise to turn an older body into a younger one.
How do we get collagen?
There are two different questions here: where dietary collagen comes from, and how we make collagen ourselves.
Animal connective tissues contain collagen. Fish skin, meat with connective tissue, and gelatin are examples; gelatin is collagen altered by processing and heat. Bone broth can contain collagen-derived protein, but its amount varies with ingredients and preparation.
Ordinary plant foods do not contain collagen. Beans, tofu, vegetables and seeds can nevertheless supply nutrients that our body uses to manufacture it.
When we digest collagen, much of it is broken down into amino acids and small peptides. Some peptides can be absorbed, but a spoonful of collagen does not travel intact to a particular wrinkle or knee. The body processes what we eat and decides how to use it.
The building materials: protein and vitamin C
Collagen contains amino acids including glycine and proline. The body can make these, and a varied diet supplies amino acids too. We do not normally need to buy them separately.
For plant-based eaters, useful protein sources include tofu, tempeh, lentils, beans, chickpeas and soy milk. Nuts, seeds and whole grains contribute as well. Eating enough overall matters: a few seeds cannot compensate for consistently inadequate meals.
Vitamin C is essential for normal collagen production. Severe deficiency weakens connective tissue and impairs wound healing. Getting enough is important; taking far more than we need is not a proven shortcut to extra collagen. [1]
| What to supply | Useful plant foods | Practical idea |
|---|---|---|
| Protein and amino acids | Tofu, tempeh, beans, lentils, chickpeas | Include a substantial protein source in each main meal |
| Vitamin C | Guava, citrus, kiwi, peppers, broccoli | Add fresh fruit or vegetables daily |
| Copper, which supports connective-tissue enzymes | Nuts, seeds, whole grains, legumes, cacao | Choose a varied diet rather than a copper supplement |
Copper has a role in connective-tissue synthesis, but more is not automatically better. Deficiency and excessive intake can both cause problems. [2]
A simple meal might be tofu with broccoli and peppers, served with brown rice. Or try lentils with vegetables and a guava afterwards. These meals provide useful building materials without needing a product labelled “collagen booster.”
What about collagen supplements?
Most conventional collagen powders are made from cattle, pigs, fish or chickens. “Marine collagen” usually means an animal product derived from fish, rather than seaweed.
Hydrolysed collagen, often sold as collagen peptides, has been broken into smaller pieces. A product labelled “vegan collagen” may instead contain nutrients intended to support collagen production. Check the ingredients: a booster is different from collagen itself. Collagen can also be produced using biotechnology, so the label needs to explain what the product actually contains.
Skin: encouraging findings, but uncertainty remains
Some reviews report improvements in skin hydration or elasticity. However, a 2025 meta-analysis found that apparent benefits were not seen in the subgroup of trials without pharmaceutical-company funding. Study quality also affected the findings. [3]
A newer review reported benefits, particularly for hydration, while acknowledging differences between products and measurements and the predominance of short studies. [4] These conflicting assessments do not justify a promise that collagen powders reverse ageing. They do justify asking who funded a trial and whether its results apply to the product being sold.
Joints: possible symptom relief is different from rebuilding cartilage
A 2025 placebo-controlled trial of 80 adults with mild knee osteoarthritis reported better pain and function with a particular fish-derived collagen product over six months. It did not find a significant improvement in joint-space width. The manufacturer funded the study, and some authors had company affiliations. [5]
That is evidence worth considering, with limitations. It does not establish that every collagen supplement works, or that it rebuilds worn cartilage.
Collagen is also an incomplete protein—it lacks tryptophan—and should not replace balanced protein sources for maintaining muscle.
Protect the collagen you already have
Food is only part of the story. Avoid smoking, protect skin from excessive ultraviolet exposure, and remain physically active with exercise suited to your abilities. Gradually progressed strength training helps maintain the muscles that support our joints.
Collagen creams may moisturise the skin, but applying collagen to the surface does not mean it replaces collagen deeper inside it.
For HealthyRetired, the sensible starting point is enough food, varied protein sources, vitamin-C-rich produce, movement and sun protection. A powder can remain an optional purchase, rather than the foundation of healthy ageing. Our body has been making collagen for decades; it needs adequate supplies, not an advertising slogan.
Before changing your diet: Consult your doctor or another qualified health practitioner before making dietary changes based on this website, particularly if you have kidney disease or another condition affecting your nutritional needs. Ask about supplements if you take medication, and check animal-derived products for allergens such as fish. Do not replace prescribed treatment with collagen.
Sources and further reading
Sources checked on 11 October 2026. Studies concern particular products and outcomes; results should not be assumed to apply to every supplement.
- NIH Office of Dietary Supplements: Vitamin C.
- NIH Office of Dietary Supplements: Copper.
- Effects of Collagen Supplements on Skin Aging: systematic review and meta-analysis, 2025.
- Oral Collagen Peptides and Skin Rejuvenation: updated systematic review and meta-analysis.
- Park and colleagues: randomised placebo-controlled trial in knee osteoarthritis, 2025.
- Dr Michael Greger's NutritionFacts.org: collagen topic and related discussions. Included as further reading; the supplement assessment above also uses the research papers directly.