Collagen Peptide Clinical Evidence

Shokuhin-To-Kaihatsu. 
Koyama Y. Effects of collagen peptide ingestion on the skin. 2009:44:10-12.

Topic: 
What are the effects of collagen peptide on the skin?

Background:

Women have been using gelatin, a form of collagen, to enhance the health of their hair, skin, and nails for ages. Can it be clinically validated that collagen ingestion improves the condition of the skin?

Study Type:

Human clinical intervention trial.

Study Design:

Placebo-controlled, double-blind. Subjects took either collagen peptide dissolved in a beverage or a placebo drink daily. At 3 and 7 weeks subjects discussed the condition of their skin with a dermatologist, who was blinded as to which subjects were assigned to which group. The water content of the stratum corneum (the outermost layer of the skin) and the skin barrier function were also measured.

Subjects:

Healthy females, aged 40-54.

Dosage:

5 g or 10 g/day for 7 weeks.

Results:

At 3 weeks, 41% of subjects in the group taking the lower dose reported that the condition of their skin had improved, while 62% of subjects taking the higher dose reported improvement. Only 10% saw improvement in the placebo group. Results were even more marked at 7 weeks. In the 10-gram group, 81% of women reported their skin condition was better, while 74% of women in the 5-gram group did. Of those in the control group, however, only 20% perceived an improvement. Interestingly, measurements of the water content in the stratum corneum and the skin’s barrier function showed no differences between the treatment groups and the control group.

Conclusion:

“These results suggest that ingestion of collagen peptide improves the function of deeper regions of the skin rather than function of the outermost epidermal regions.” 

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Journal of Agricultural and Food Chemistry. 

Iwai K, et al. Identification of food-derived collagen peptides in human blood after oral ingestion of gelatin hydrolysates 2005;53:6531-6. 

Topic: 
Do collagen peptides enter the bloodstream after ingestion of gelatin hydrolysates?

Background:

Is gelatin, in the form of collagen peptides, absorbed by the human body? 

Study Type:

Human clinical intervention trial.

Study Design:

Subjects ingested gelatin from pig skin, chicken feet, and cartilage after fasting for 12 hours. 

Subjects:

Healthy subjects 

Dosage:

9.4-23 g, dose 

Results:

At baseline, only negligible amounts of the peptide form of hydroxyproline (Hyp) were found. After the subjects ingested collagen, Hyp levels increased significantly, reaching a peak of blood levels of 20-60 nmo/ml at 1-2 hours and then falling to half that level at 4 hours. Pro-hyp was the major constituent of collagen peptides detected. Other peptides, such as Ala-Hyp, Ala-Hyp-Gly, Pro-Hyp-Gly, Leu-Hyp, Ile-Hyp, and Phe-Hyhp were found at “small but significant” levels. 

Conclusion:
Collagen peptides are absorbed, as evidenced by their presence in human blood 1-2 hours after ingestion. 

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Arch Dennat and Syph. 

Rosenberg S, et al. Further studies in the use of gelatin in the treatment of brittle nails. 1957:76:330-5. 

Topic: 
Can taking collagen improve the quality of brittle nails?

Background:
Brittle nails are common among women. Can collagen help? 

Study Type:
Human clinical intervention trial.

Study Design:
Subjects’ nails were assessed at baseline, upon trial completion, and after cessation of collagen treatment. 

Subjects:
50 subjects 

Dosage:
7 g/day 

Results:
43 subjects (86%) saw improvement in the quality of their nails. Additionally, when the treatment ceased, the nail defects returned. 

Antibiotic Medicine and Clinical Therapy. 

Schwimmer M and Mullnos M. Salutary effects of gelatin on nail defects in normal subjects. 1957:4:403-7. 

Topic: 
Can taking collagen improve nail defects?

Background:
Can collagen build strong, healthy nails? 

Study Type:
Human clinical intervention trial.

Study Design:
Subjects’ nails were assessed before and after taking collagen. 

Subjects:
Healthy subjects 

Results:
80% of subjects saw improvement in their nails after taking collagen peptide. 

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Nutritional Reports International. 
Scala J et aI., Effect of daily gelatine ingestion on human scalp hair. 1976:13:579-92. 

Topic: 
Does a daily dose of collagen improve hair health?

Background:
Hair, nails and the stratum corneum level of the skin are all made of the same substance: keratin. Previous studies have shown that taking collagen can have a beneficial effect on nail health. Does it work for hair as well? 

Study Type:
Human clinical intervention trial.

Study Design:
Subjects took collagen for 62 days. The thickness and strength of their hair was measured at baseline, upon trial completion, and after cessation of collagen treatment. 

Subjects:
Male and female adults 

Results:
Thickness and strength of the hair increased significantly. The increase in thickness was greater for women than for men, possibly because the women’s hair was thinner at the onset of the study. After treatment stopped, hair thickness returned to its original level.

Collagen Peptide Mechanism of Action:

Collagen peptide contains amino acids, such as proline and cysteine, which serve as the building blocks of keratin (the main structural protein of the hair, nails, and stratum corneum). The skin uses amino acids to repair damage and to replace skin cells and collagen tissue. Supplementation with collagen peptide not only increases levels of collagen in the skin — which makes skin more firm and supple — but also reduces the activity of the enzyme collagenase, a matrix metalloproteinase that breaks down collagen in the extracellular matrix (or the spaces between cells). 

Interestingly, while most proteins are digested and absorbed as amino acids, at least part of collagen is absorbed intact as oligopeptides. These oligopeptides are believed to reduce UVB damage and support the skin’s recovery from UVB exposure by using cells’ signaling pathways. Writing in the Journal of Agricultural and Food Chemistry in 2009, Shigemura and associates wrote that “…collagen peptide exhibits its effects on health and beauty through mechanisms unique to collagen peptide” and that “Collagen has unique properties that are not found in other proteins, and these properties may be the reason for the effects of collagen peptide ingestion on bones, joints, skin, hair and nails.”