Dear Miranda. I am no expert in this area. But I have my doubts on such research. Let me explain my thought. Is one thing when the product is natural, and another when it is grown artificially. I think that this issue is not addressed in the studies. Then it is possible to strike at the an artificial product.

We know that by the time we reach 25 or 30, the stores of collagen are reduced, leading to several manifestations of aging.  Is consuming collagen products a right answer at all?  Is there evidence?  Perhaps men and women are all concerned about this matter, and not just the women only.

Dear Miranda. I am no expert in this area. But I have my doubts on such research. Let me explain my thought. Is one thing when the product is natural, and another when it is grown artificially. I think that this issue is not addressed in the studies. Then it is possible to strike at the an artificial product.

I am not also a specialist on this topic, but the fact that TV has so many advertisements about collagen makes me suspicious, since most of the times TV products are just expensive 'garbage'. I am waiting the opinions of the experts with interest...

Dear Miranda,

like Vyacheslav, I´m no expert. But I´ve learned my lessons. Collagen and other proteins are digested in the human intestinum. During this process they are divided into amino acids. That means, that the original structure of these long-chained molecules is destroyed. So I have no idea, how these proteins could help to modify the human skin, if they are eaten and stomached.

Dear friends, @Vyacheslav, @ Demetris: I'm also waiting for 'evidence'. My old students went for training at community pharmacies.  They are doing the Bachelor of Pharm Sciences.  All of them informed me that collagen products are selling like hot cakes :)

I have been very careful in some ways.  I stopped drinking a lot of coffee because that seems to dehydrate the skin, and prevents great prolonged sleep till morning.  Good sleep means good skin.

Dear Hanno, all of us have the protein breakdown enzymes and protein synthesis enzymes.  Normally the amino acid sequences of proteins in humans only differ slightly from animals.  But we need the raw materials, and the enzymes need to be active to do the job.  Let's see if the dermatologists and the doctors and biology based researchers can enlighten us.  (I'm not even allowed to research these areas.)

Dear Miranda,

yes let´s wait. I´m very convinced, that collagenes are bestsellers, but their impact?

Dear Miranda

I am not an expert, but the information from my reading is here. Collagen is the most abundant structural protein in the body. It represents about 70% of the body connection tissue and is necessary for the creation of skin, muscle, bone and cartilage. This protein has a recognised position as functional ingredient thanks to its well known and identified health promoting properties. Its use will be progressively raising according to the gain in popularity that is constantly achieving.

Collagen from fish origin is considered to bring the same benefits than the one obtained from mammalians with the added value of its universally accepted origin.

Here are a few research reports of use:

http://www.nutritionladder.com/articles/Circulation2002(106)omega3.pdf

Dear Cecilia, thanks, it's done!  Collagen would be part of the bone matrix, so strengthen the bones.  May be good for those who complain of weak knees :)  Do you have the softcopy or online link for this article?

Friends, it's not just ladies buying collagen like hot cakes :)

Thanks Prof N.  You are the first to find evidence.  I will go through all the links. Thanks also for this: 'Collagen is the most abundant structural protein in the body. It represents about 70% of the body connection tissue and is necessary for the creation of skin, muscle, bone and cartilage. This protein has a recognised position as functional ingredient thanks to its well known and identified health promoting properties. Its use will be progressively raising according to the gain in popularity that is constantly achieving.

Collagen from fish origin is considered to bring the same benefits than the one obtained from mammalians with the added value of its universally accepted origin.' KOSHER :)

My dear @Miranda, here I am after two days absence. As many of my predecessor, I am not an expert in the field and the question of benefit of consuming fish collagen or silk peptides. But, I do have some skills to find papers, articles, comments...etc about the issue!

About skin health :"A preclinical study investigated the effects of oral ingestion of hydrolyzed collagen, along with vitamin C and glucosamine, suggested that the moisture content of skin, its viscoelastic properties, and smoothness benefit.The mechanism of action of ingested hydrolyzed collagen on skin may be the increased density of collagen fibrils and the fibroblasts' density (the fibroblasts being the main cells of the dermis, and those producing collagen). It may be that that the peptides of ingested hydrolyzed collagen have chemotactic properties on fibroblasts or an influence on growth of fibroblasts."

http://www.ntlab.co.uk/#!fish-collagen-peptides/c1mrf

http://www.ntlab.co.uk/#!stemsilk/c7vd

Thanks dear friends @Profs Ljubomir, Nageswara, Cecilia et al.  This is going to be so helpful to anyone with weak knees, back aches etc.

For our friends who prefer wholesome food: 'Deriving its name from the Greek word kolla, collagen is indeed a vital element that helps to keep the body functioning. Fortunately, there are a number of foods that help to support the creation of collagen within our bodies. Here are a few examples of the many different foods that provide the building blocks for the collagen production.

Soy products such as soymilk and cheese contain an element known as genistein. The presence of genistein gives soy products their collagen production qualities, as swell as helping to block enzymes that tend to break down and age the skin. Just about any soy product contains enough genistein to be helpful, including soy products that have been developed as substitutes for meat products.

Dark green vegetables are also excellent examples of foods containing collagen producing agents.'

http://www.wisegeek.org/which-foods-contain-the-most-collagen.htm

From Prof Ljubomir's link, on silk peptides:

'Silk peptides are a mixture of amino acids obtained from the cocoon of the Silk Worm Bombix Mori. The mixture of amino acids is very high in the amino acids serine and aspartate, and some versions are rich in tyrosine as well.  

The protein can be found in a hydrolyzed (pre-digested) form known as Sericin-S, or as a undigestible form known as Sericin-L. The undigestible form appears to exert protective effects on the colon and intestinal tract, whereas the hydrolyzed form can beneficially affect systemic (post-intestinal) metabolic functions.

Sericin also appears to beneficially affect the skin, in both a protective sense (anti-oxidation, anti-UV radiation) as well as increasing moisture content.'

http://www.ntlab.co.uk/#!silk-peptides/c1xhj

From the same link, this is on fish collagen peptides:

'Fish Collagen Peptides

Collagen is an important protein that exists ubiquitously in the body. It is naturally contained in high amounts in the skin, bone, joint cartilage, blood vessels, tendons, and teeth and occupies one third of total body protein maintaining youthfulness, health and beauty.

As we become old, our body's collagen production reduces which results to wrinkles, joint problems, and arthritis. But, these signs of aging can be treated if not permanently at least the process of the aging can be slowed down if supplement is taken. Most collagen supplements claimed to provide the answers in helping you looking young and feeling young as these supplements replenish the reducing supply of natural collagen in our body.'

http://www.ntlab.co.uk/#!fish-collagen-peptides/c1mrf

From the same link' on plant stem cells (apple and grape are described).

'Plant Stem Cell

Plant stem cells are characterized by two distinctive properties: the ability to create all differentiated cell types and the ability to self-renew such that the number of stem cells is maintained. Plant stem cells never undergo aging process but immortally give rise to new specialized and unspecialized cells, and they have the potential to grow into any organ, tissue, or cell in the body. Thus they are totipotent cells equipped with regenerative powers that facilitate plant growth and production of new organs throughout lifetime.'

http://www.ntlab.co.uk/#!plant-stem-cell/cqxa

It is a banned substance which had been claimed for aesthetic builder for facial and muscle tone.... enclosed a FDA report.

http://www.fda.gov/ucm/groups/fdagov-public/@fdagov-foods-gen/documents/document/ucm267039.pdf

Dear Krishnan,

thanks for the really interesting documents.

Prithvi, this is what I get to read from the springer link you sent:

'Dietary supplements (vitamins, polyphenols, micronutrients and proteins) have demonstrated beneficial effects on skin health. The classical route of administration of active compounds is by topical application and manufactures have substantial experience of formulating ingredients in this field. However, the use of functional foods or nutraceuticals for improving skin condition is increasing. The preclinical efficacy assays and bioavailability trials provide a basis from which to establish appropriate collagen hydrolysate (CH) intakes that might impact skin health outcomes.'

http://link.springer.com/article/10.1007/s00403-008-0888-4

This info is from the sciencedirect link:

'The most abundant sources of gelatin are pig skin, bovine hide and, pork and cattle bones, however, the industrial use of collagen or gelatin obtained from non-mammalian species is growing in importance. The classical food, photographic, cosmetic and pharmaceutical application of gelatin is based mainly on its gel-forming properties. ... In the last decade, a large number of studies have dealt with the enzymatic hydrolysis of collagen or gelatin for the production of bioactive peptides.'

http://www.sciencedirect.com/science/article/pii/S0268005X11000427

Thanks @Krishnan Umachandran:  I read the report on silk peptides.  GRAS means generally regarded as safe, so silk protein isn't GRAS.  

From http://www.fda.gov/ucm/groups/fdagov-public/@fdagov-foods-gen/documents/document/ucm267039.pdf; 'As discussed more fully below, your notice dated June 27, 2002, fails to support a conclusion that silk protein hydrolysate is GRAS.'  

Fish collagen has some undesirable side effects & silk peptide has not been prepared by a good safe procedure so far. I think it is better to avoid both materials. Of course, one will keep eating fish in the usual normal way  removing bones & possibly skin. Some food supplements are a "business" seeking profits & not aiming at better human health.

As always, Kamal's reply is very helpful.

Prof Kamal, do you have a softcopy of the second article, 'Utilization of seafood processing by-products: medicinal applications. Adv Food Nutr Res. 2012;65:495-512. doi: 10.1016/B978-0-12-416003-3.00032-9.'?  It will be useful, thanks.  

Thanks Prof Kamal, I will wait for it.  And please send some copies on Ethics or Bioethics, if you happen to have some.  Thanks so much.