Does heat destroy collagen?

The factory's heat: what collagen's structure is, what heat does to it, and why a supplement arrives already past the point the question worries about

Does heat destroy collagen is a question that is asked about three different things by three different readers, one stirring a scoop into coffee, one wondering about the oven and the stock pot, one sitting in a sauna, and the honest page answers for each because the answer differs and the shelf's usual reassurance covers only the first. The place to start is the factory, because the factory's heat is the one that does destroy collagen's structure, and it does so deliberately, before the tub is sealed. Native collagen, the collagen in a cow's hide, a fish's skin or a reader's own tendon, is a triple helix: three long chains of amino acids, each a thousand or so long with glycine at every third position, wound around each other into a tight rope, with the ropes packed side by side into fibrils and the fibrils into fibres, and the whole held together by hydrogen bonds between the chains and by cross-links between the ropes. Heat breaks the hydrogen bonds. At around sixty degrees or so in water, the exact temperature depending on the source and the conditions, the helix unwinds, the three chains separate and uncoil into a tangle of single strands, and the structure that made collagen a tough, insoluble fibre is gone; the tangle of unwound strands is gelatin, the protein that dissolves in hot water and sets a jelly as it cools because the strands partially re-tangle, and it is why a long-cooked joint falls apart and a stock sets in the fridge. The manufacture of a collagen supplement is exactly this process carried further. Cattle hide, bovine bone or fish skin is cleaned and treated with acid or alkali to loosen the matrix, the collagen is extracted with heat into gelatin, the gelatin is then treated with enzymes that cut the long unwound strands into short peptides of a few to a few dozen amino acids, and the result is filtered and spray-dried into hydrolysed collagen, the powder in the tub or the capsule, which dissolves in cold water and tastes of nothing precisely because the helix and the long strands that would have made it gel are gone; the difference between the two stages, gelatine against hydrolysate, is on the gelatin and collagen page. So the collagen in a supplement has already been heated past the point the question worries about, twice over: its helix was unwound in the extraction and its strands were cut in the hydrolysis, and what arrives in the capsule or the scoop is a collection of peptides and free amino acids with no structure left for any further heat to destroy. The shelf's reassurance that collagen peptides are heat-stable is true and is true for this reason, which is not the reason the shelf gives: they are stable not because they are tough but because the destruction has already been done, and a reader who worries that heat will damage their collagen supplement is worrying about damaging something the factory damaged on purpose and sold them the pieces of.

The kitchen's heat and the body's heat: what a kettle, an oven and a stock pot do to peptides, the one passenger that heat does hurt, what a sauna does to a tendon, and the worked example

The kitchen's heat is the one the first reader means, and the honest page can now answer it in a sentence and then explain the sentence: hot coffee, hot soup, a hot smoothie or an oven does nothing to the collagen in a supplement. The peptides in hydrolysed collagen are already unwound and already cut, and a kettle cannot unwind what has no helix or cut what is already short; their amino acids, which are the units the body absorbs, are small molecules that survive the far higher temperatures of ordinary cooking in every protein food a reader has ever eaten, the roast, the grilled fish, the fried egg, with the exception of a few that brown and react at high dry heat over long times, which is the chemistry of a crust and not of a cup of coffee at ninety degrees for five minutes; the coffee myths for collagen and creatine together are dispatched on the collagen, creatine and coffee page. A collagen scoop can be stirred into any hot drink, added to soup or porridge, or baked into something, and the collagen that reaches the gut is the same peptides and amino acids it would have been cold. Bone broth is the kitchen's heat doing the factory's first job at home: simmering bones and skin for hours unwinds the collagen in them into gelatin and draws it into the liquid, which is why a good stock sets when cold, so that the stock pot is heat extracting collagen rather than destroying it, and the gelatin in a bowl of broth is collagen at the first stage of the process the supplement completes. The one thing in a collagen capsule that kitchen heat does hurt is not the collagen. Vitamin C, the passenger that lets the label carry its collagen formation sentence, is the least heat-stable of the common supplement ingredients, degrading with heat, light, air and time, so that a reader who empties the capsules into boiling water or bakes them into something loses some fraction of the 12mg of vitamin C and none of the 1200mg of collagen; since a reader eating fruit has vitamin C to spare and 12mg is a label threshold rather than a dose, the loss matters to the label's sentence and not to the reader, and the two durations of a bottle, in use and on the shelf, where the vitamin C is again the thing that ages, are on the how long a bottle lasts page. The body's heat is the third reader's question and the simplest. A sauna at eighty or ninety degrees heats the air and the skin's surface, and the body's core climbs by a degree or two before the reader leaves; hot yoga, a fever, a hot bath or a heatwave do the same or less; and a body at forty-two degrees is a medical emergency long before any tissue approaches the sixty degrees or so at which collagen's helix unwinds, so that the collagen of a reader's skin, tendons, ligaments and bone is exactly where it was after any heat a living person survives, and the sauna neither destroys nor, as the other half of the shelf claims, stimulates it. What heat does to the body's collagen over years is indirect and runs through a different mechanism: the sun's ultraviolet light, which is not heat but radiation, switches on the enzymes that degrade dermal collagen, and that destruction is real and large and is on its own page. The worked example is the already-heated, already-cut protein with its heat-sensitive passenger, stated on its true terms: two capsules, 1200mg hydrolysed type 1 marine collagen with 12mg vitamin C at 15% of its reference value plus zinc, 120 for £16.99 at 28p a day, lab tested and UK made, the collagen indifferent to any kitchen heat and the vitamin C degraded by it, carrying vitamin C's collagen formation sentence and no claim for the collagen, which is swallowed whole from the capsule or emptied into anything hot or cold with the same result. Does heat destroy collagen: yes, at the factory, on purpose, into the peptides that are the product; no, in the kitchen, where only the vitamin C suffers; and no, in the body, where no survivable heat comes near the temperature that matters.

What to check on the label