Gut healing properties of gelatin?
In light of increasing social and general media hype about the gut-healing properties of gelatin (or gelatine, depending where you come from) I decided to investigate the properties of gelatin, in case it was going to be of benefit to those with functional gut conditions like Irritable Bowel Syndrome (IBS).
What is gelatin?
It turns out there is nothing too special about gelatin in terms of composition, being made up of the same component parts as its “parent” collagen. It is nearly pure protein, with the majority being the non-essential amino acids glycine and proline (which can be made by the human body)(2). While gelatin is not special because of what it is made up of, it does have some unique qualities. Gelatin has been used throughout history for its useful gelling power, not only in cooking but in photography, medicine and glue-making. The amino acids in collagen from animal bones, cartilage and skin change their formation to become gelatin when boiled then cooled, and this process sets surrounding liquids.
How is gelatin digested?
But does this mean that gelatin can “heal the gut” by forming a protective barrier between the outside world and the blood stream and internal organs? Unfortunately I think the answer is no, it does not. Why not? Gelatin is digested back to a liquid by the enzyme gelatinase in the stomach, forming smaller proteins called polypeptides, before eventually being broken down to amino acids before entering the blood stream from the intestine. Gelatin itself does not make it beyond the stomach in digestion, so it can’t get to the place where it could heal the gut, nor in a form that could heal the gut.
If it is so obvious that gelatin does not make it intact to the intestine, one of the parts of the body that it is claimed to have the most action, and is made up predominantly of amino acids that can be easily produced by the body from any old protein food, then why is there so much mis-information about it’s amazing curative, restorative and preventative properties?
I have come to the conclusion that much of the mis-information about gelatin/gelatine comes from the readily accessible information on the internet about the medication gelatine tannate. This combined form of modified gelatin and tannic acid has scientific evidence to support its role in the treatment of gastro-intestinal conditions. For example, gelatine tannate has been shown to confer protection to the bio-barrier membrane by forming a protective adhesive film in both adults (3) and children (4). In capsule form the medication resists systemic digestion (normal digestion of gelatin in the stomach) and the combination of (mainly) tannic acid and gelatin actions exert effect in the intestine. It requires a long stretch of the imagination to therefore assume that edible gelatin in the form of gummy bears or set jellies or bone broths will result in the same gut actions.
We need more evidence
If anyone can find some rock solid evidence that gelatin, on its own in edible form does resist digestion in the stomach, make its way to the small intestine and exert some preventative or restorative influence, I would love to see it, but in the meantime I will stick to eating foods that contain gelatin purely for their culinary qualities rather than nutritional ones.
(1) Freli V, Moreira da Silva R, Pescio P. New insights into the mechanism of action of gelatine tannate for acute diarrhoea. Part 1: film-forming effect. Presented as oral communication at the 33rd edition of the Congress from the Groupe Francophone d’Hépato-Gastroentérologie et Nutrition Pédiatriques in Nantes, France, on 30th March 2012 http://www.tasectan.ie/wp-content/uploads/2012/10/1.1_Abstract_GFHGHP-2012_1stPart.pdf.
(2) Gelatin Manufacturers Institute of America Gelatin Handbook 2012 Massachusetts USA Accessed on 12/12/15 from http://www.gelatin-gmia.com/images/GMIA_Gelatin_Manual_2012.pdf
(3) Allegrini A, M Costantini M. Gelatin tannate reduces the proinflammatory effects of lipopolysaccharide in human intestinal epithelial cells J Gastroint Dig Syst 2012, 2:3
(4) Esteban Carretero J, Durban Reguera F, Lopez-Argueta Alvarez S, et al. A comparative analysis of response to vs. ORS+ gelatin tannate pediatric patients with acute diarrhea. Rev Esp Enferm Dig. 2009;101:41–48.