Collagen and diet: what to eat boost and protect your skin.
Collagen is the protein that structures our dermis. Over time, its reduction is responsible for skin slackening. Our diet can influence its production, protecting it or, on the contrary, accelerating its degradation. To find out more, see our dossier on the best collagen supplements.
Three levers to act through the plate.
As we age, our bodies naturally produce less collagen, resulting in the appearance of wrinkles. Added to this are external aggressors - sun, pollution, tobacco - which generate collagen-destroying free radicals. More bad news: the quality of collagen produced also declines. Hence the importance of a diet that encourages collagen production, combined with a good anti-ageing skin care routine.
The bricks
Proteins rich in proline and lysine, vitamin C, sulfur and zinc, which help build collagen.
The existing
Antioxidants (vitamins A, E, lycopene) and isoflavones defend collagen already present.
Enemies
Unhealthy industrial fats and sugar, which accelerate collagen breakdown.
Understanding collagen.
Collagen belongs to the family of structural proteins that build the body's architecture. It is essential to skin firmness, and alone represents a quarter of the protein mass of our organism.
There are many types of collagen, but their manufacture varies little. Its basic structure, tropocollagen, consists of a triple helix of polypeptides made up of amino acids such as glycine, proline, hydroxylysine and hydroxyproline. Multiple reactions are required to arrive at the final form of collagen.
One of these reactions, the hydroxylation of lysine and proline, requires vitamin C. That's what this article is all about: identifying the foods that provide the right amino acids, those that help make collagen and those that protect existing collagen. Severe vitamin C deficiency is the cause of scurvy, a disease linked to a defect in collagen production, which struck sailors deprived of fruit and vegetables during long crossings. (role of vitamin C in collagen synthesis).
The formation of the helix also requires disulfide bridges, which explains the importance of sulfur-rich foods, as we'll see later. Once the triple helix has been formed, procollagen leaves the cell and completes its maturation in the extracellular environment.
Foods that provide collagen building blocks.
Very few foods contain collagen as such: there's bone broth, eggs, gelatin, crustacean shells and the skin of fish such as salmon. But it's far more relevant to turn to the foods essential to its production, rich in protein and key amino acids such as lysine and proline.
Proline
The body knows how to manufacture it. But since collagen represents a quarter of our protein mass, our needs are considerable, and a dietary intake is still necessary.
Lysine
Our bodies can't synthesize it: it has to come from our diet. Very important for collagen production, it also reduces the frequency of herpes labialis outbreaks.
The complements of collagen peptides.
Let's tackle a controversial subject: supplements containing collagen peptides. Peptides are associations of several amino acids, in this case those present in natural collagen.
Some studies suggest that it may be of interest. Researchers have shown, for example, that hydroxyproline intake can increase hyaluronic acid production in vivo, and clinical trials have reported improvements in elasticity, hydration and fine lines. But these studies remain few in number, sometimes contradictory, and often financed by the laboratories that market these supplements.
Data are limited and do not allow us to make a definitive statement. If your diet is well-balanced, these supplements are probably not necessary. If your diet is less balanced, an occasional course of treatment may be justified. It's up to each individual to make an informed choice.
Other foods with anti-aging action.
Citrus & vitamin C
Vitamin C contributes to the formation of the collagen triple helix. It is also an antioxidant against free radicals - beneficial when consumed as an applied serum.
Garlic & sulphurous foods
Garlic boosts collagen: in addition to its anti-inflammatory properties, it is rich in sulfur, essential for collagen's disulfide bridges.
Zinc
Zinc-rich foods are useful, although it's rare to run out.
Soy isoflavones
They slow down the action of collagenase, the enzyme that breaks down collagen. (Sin BY, Kim HP, 2005). Also known as phytoestrogens, they partially compensate for the drop in ovarian estrogens, but more modestly than synthetic estrogens: around 30 % of relieved women, versus 70 %. Long-term use has not been studied.
Like all hormone-mimetic foods, soy can be both beneficial and problematic. A 2018 study advises against isoflavone supplementation, on the precautionary principle, for pregnant women, people with thyroid disorders or a history of breast cancer. Soy can also promote acne via an increase in IGF-1: avoid in cases of acne-proneness.
Rich foods in antioxidants.
After the foods that make collagen, let's move on to those that protect existing collagen: antioxidants, which defend it against free radicals.
Orange vegetables
Important for collagen synthesis and repair. Vitamin A and beta-carotene have antioxidant and radiance-enhancing properties. However, vitamin A supplementation is not recommended: the risk of overdosing makes it potentially more harmful than beneficial.
Red fruit & vegetables
Lycopene is one of the most powerful antioxidants, helping the body to fight off external aggression.
Avocado, salmon, almonds
This antioxidant protects the skin from UV rays and prevents damage caused by free radicals.
Green leaf vegetables
Folic acid is involved in amino acid metabolism and DNA production. Particularly useful for rapidly-renewing cells, including skin cells, it plays a role in cell repair.
Essential fatty acids
Monounsaturated omega-3, omega-6 and omega-9 contribute to the lipid cement between epidermal cells. Anti-inflammatory, they help combat collagen degradation, promote the absorption of vitamins A and E, and boost hydration.
The food to avoid.
Bad fats
Those of industrial origin, often indicated by the words «partially hydrogenated» on the packaging. They raise bad cholesterol (LDL), lower good cholesterol (HDL) and create inflammation that accelerates aging and collagen degradation.
Sugar & glycation
Sugar causes protein glycation the binding of sugar to proteins. Once glycated, they swell and can no longer be eliminated. They accumulate, degrading elastin and collagen, and accelerating skin ageing.
What you need remember.
Protecting and stimulating collagen through diet is based on three pillars.
Bring the bricks
Protein rich in proline and lysine, vitamin C, sulfur, zinc.
Protecting existing assets
Antioxidants (vitamins A, E, lycopene) and isoflavones, with the precautions mentioned.
Avoiding enemies
Bad industrial fats and sugar.
Nutrition remains a complementary lever in a good anti-aging skin care routine, never a substitute.
Your questions about collagen and nutrition.
Which foods help build collagen?
Are collagen peptide supplements effective?
Is soy good or bad for the skin?
Which foods accelerate collagen breakdown?
Is diet enough to preserve collagen?
Information for educational purposes only. It does not replace a medical consultation. This article summarizes data on the role of diet in the production and protection of skin collagen; levels of evidence vary, and certain avenues (peptide supplements, isoflavones) remain debated. Any supplementation or major change in diet, particularly in the case of pregnancy, thyroid disorders or a history of hormone-dependent cancer, should be discussed with a physician. No commercial partnership links this page to the products or supplements mentioned. BeautyDecoded - Independent information. Dr Sylvain David, Plastic and aesthetic surgeon - Founder of BeautyDecoded.