Here’s a bunch of studies on the dietary collagen and photoaging prevention:
Conclusion: Meta-analysis of 11 different randomized, placebo-controlled trials involving 805 subjects total testing a variety of different types and doses of oral collagen supplements found that all of the studies’ results showed oral collagen supplements improve wound healing, skin aging, skin elasticity, skin hydration, and skin collagen density.
A Collagen Supplement Improves Skin Hydration, Elasticity, Roughness, and Density: Results of a Randomized, Placebo-Controlled, Blind Study (2019)
Conclusion: Randomized control trial had 72 middle-aged and elderly women orally receive either a 2.5g collagen supplement or placebo daily for 12 weeks. Changes were measured in skin hydration, elasticity, roughness, and density. Results: “The test product significantly improved skin hydration, elasticity, roughness, and density. The differences between the verum group and the placebo group were statistically significant for all test parameters.” After stopping the supplementing regimen, these effects were found to be “substantially” retained in the intervention group at the one month follow up, demonstrating that the benefits are long-lasting.
Daily Oral Supplementation With Collagen Peptides Combined With Vitamins and Other Bioactive Compounds Improves Skin Elasticity and Has a Beneficial Effect On Joint and General Wellbeing.(2018)
Conclusion: Randomized, double-blind, placebo-controlled trial had 120 participants orally consume either a fish collagen supplement or a placebo daily for 90 days. Results: “Subjects consuming the test product had an overall significant increase in skin elasticity (+40%; P < .0001) when compared to placebo. Histological analysis of skin biopsies revealed positive changes in the skin architecture, with a reduction in solar elastosis and improvement in collagen fiber organization in the test product group. As reported in the self-perception questionnaires, these results were confirmed by the subjects’ own perceptions in that participants agreed their skin was more hydrated and more elastic. In addition, the consumption of the test product reduced joint pain by -43% and improved joint mobility by +39%. Oral supplementation with collagen bioactive peptides combined with chondroitin sulphate, glucosamine, L-carnitine, vitamins, and minerals significantly improved the clinical parameters related to skin aging and joint health, and therefore, might be an effective solution to slow down the hallmarks of aging.”
Conclusion: 35 ladies were given a daily oral collagen supplement for three months. Ultrasound analysis of their skin found that “there was a significant improvement of firmness and elasticity and an increase in dermal thickness.”
Effect of Collagen Hydrolysates from Silver Carp (Hypophthalmichthys Molitrix) Skin on UV-induced Photoaging Mice: Molecular Weight Affects Skin Repair (2017)
Conclusion: Scientists tested the ability of silver carp fish skin collagen to repair and prevent photodamage in mice and found that the collagen supplements were effective for significantly reducing post-UV exposure sunburn and wrinkle formation and increased skin moisture retention.
Effect of Orally Administered Collagen Peptides from Bovine Bone on Skin Aging in Chronologically Aged Mice (2017)
Conclusion: Mice were given oral collagen peptide supplements daily for 8 weeks. Scientists found that the collagen supplementation “significantly improved the skin laxity, repaired collagen fibers, increased collagen content and normalized the ratio of type I to type III collagen in chronologically aged skin.”
The Effect of Oral Collagen Peptide Supplementation on Skin Moisture and the Dermal Collagen Network: Evidence From An Ex Vivo Model and Randomized, Placebo‐Controlled Clinical Trials (2015)
Conclusion: Two studies in one.
First one: 33 middle-aged Japanese women were randomly assigned to orally receive either a placebo, a 10g fish collagen supplement, or a 10g pig collagen supplement daily for 8 weeks to test its effect on skin moisture retention. Both collagen groups enjoyed a “significant” skin moisture level increase compared to the placebo group.
Second one: 106 French white women were randomly assigned to orally receive either a placebo or 10g collagen supplement for 12 weeks to test the effect of the supplement on skin collagen density and fragmentation. The collagen group demonstrated a “highly significant increase” in skin collagen density and significantly less collagen fragmentation.
Oral Intake of Specific Bioactive Collagen Peptides Reduces Skin Wrinkles and Increases Dermal Matrix Synthesis (2013)
Conclusion: 114 middle-aged women were randomly assigned to orally receive either a 2.5g collagen supplement daily or a placebo for 8 weeks to test the effect of oral collagen supplements on eye wrinkle formation (crow’s feet) and skin levels of collagen and elastin. The collagen group enjoyed significant reduction in eye wrinkles and an increase in skin collagen and elastin. These effects were also observable a month after discontinuation of the collagen supplementation.
Oral Supplementation of Specific Collagen Peptides Has Beneficial Effects on Human Skin Physiology: A Double-Blind, Placebo-Controlled Study (2013)
Conclusion: 69 middle-age women were randomly assigned to receive a 5g collagen supplement, 2.5g collagen supplement, or placebo daily for 8 weeks to test the ability of oral collagen supplements on improving skin elasticity, skin moisture, skin moisture evaporation, and skin roughness. Both doses produced a significant improvement in skin elasticity, with slight improvements in skin hydration.
Effects of Collagen and Collagen Hydrolysate from Jellyfish Umbrella on Histological and Immunity Changes of Mice Photoaging (2013)
Conclusion: Scientists tested the ability of jellyfish collagen to repair and prevent photodamage in mice and found that the collagen was effective for improving skin moisture retention, measurably repaired skin collagen and elastin, reduced wrinkle formation and photodamage from UV exposure.
Conclusion: 29 ladies were given a 1g collagen supplement to take daily for six months and underwent facial scans at baseline, at 3 months, and then at 6 months. Results – “Participants had significant improvements in their percentage of facial pores and ultraviolet spots from baseline to 6 months. Body and skin satisfaction also improved significantly from baseline to 6 months, and were positively correlated at the baseline, 3-, and 6-month assessment points.” The supplement effectively healed photodamage.
Effects of Collagen Tripeptide Supplement on Photoaging and Epidermal Skin Barrier in UVB-exposed Hairless Mice (2012)
Conclusion: To test the ability of oral fish collagen supplements to heal photodamage, scientists induced UVB photodamage in groups of hairless mice for 14 weeks. Two groups received the collagen supplements during this time and the other groups did not. The collagen groups enjoyed fewer wrinkles, better skin hydration, less sunburn, increased skin elasticity, and reduced expression of matrix metalloproteinases (MMPs), the enzymes responsible for skin collagen breakdown.
Conclusion: Hairless mice were repeatedly subjected to photodamaging levels of UVB irradiation for 6 weeks while being given a daily oral fish collagen supplement in order to test the effectiveness of the collagens supplement on skin hydration levels, skin collagen composition, and epidermal thickness. Another group of mice received the same UVB exposure, but no collagen. The non-collagen mice experienced a significant reduction in skin hydration levels, while the collagen-supplemented group was protected from this UVB side effect and demonstrated much better skin hydration. The non-collagen mice also experienced a major reduction in the amount of type 1 collagen in their skin, while the supplemented mice maintained a type 1 collagen level that was more than double the non-collagen group.