Can you take collagen if you have keloids?

Supply and signal: what a keloid is, why every treatment acts on the signal, and what eaten collagen is

Can you take collagen if you have keloids is one of the most sensible worries a reader brings to a collagen supplement, because a keloid is made of collagen, too much of it, and the instinct that eating more collagen might feed it is the instinct of someone who has understood what a keloid is; the honest page respects the worry and answers it by separating two words that it runs together, supply and signal. Start with the keloid. When skin is wounded, by a cut, a piercing, acne, a burn, a surgical incision or a vaccination, fibroblasts arrive at the wound and deposit collagen in response to transforming growth factor beta and the other signalling molecules of wound healing, and in most people the signals switch off as the wound closes, the deposition stops and the scar flattens over the following year. In a keloid-prone person the fibroblasts in that patch of skin over-respond to the same signals, deposit far more collagen than the wound needs, deposit it in thick, disorganised, whorled bundles rather than the orderly basket-weave of normal dermis, and keep depositing beyond the edges of the original wound for months or years, producing the raised, firm, often itchy or tender scar that is a keloid and that distinguishes it from a hypertrophic scar, which stays within the wound's edges and tends to settle. What drives the over-response is local and inherited: keloids run in families, occur at much higher rates in darker skin, and favour particular sites, the chest, the shoulders and upper back, the earlobes and the jawline, so that the same person may form a keloid on the chest and a flat scar on the forearm, which is itself the proof that the problem is in the fibroblasts of that patch rather than in anything circulating through the whole body. Every treatment that works acts on that local signalling and deposition. Corticosteroid injected directly into the scar suppresses the fibroblasts' collagen synthesis and softens and flattens the keloid over a course of injections. Silicone sheets and gels worn over the scar for months reduce its growth by mechanisms that are still debated. Pressure garments and pressure earrings after earlobe keloid surgery do the same. Cryotherapy freezes the scar tissue. Lasers target its vessels and its bulk. And surgery alone is avoided, because cutting out a keloid creates a new wound in keloid-prone skin and the signalling restarts, often producing a larger keloid than the one removed, so excision is combined with injected steroid, radiotherapy or pressure to suppress the response. Now the collagen supplement. Eaten collagen, whether marine or bovine, hydrolysed or gelatin, is a protein, and the gut treats it as it treats every protein: the enzymes of the stomach and small intestine cut it into amino acids and short peptides of two or three amino acids, which are absorbed into the blood and join the body's general amino acid pool, the same pool that every meal's protein joins and from which every cell in the body draws what it needs. The collagen supplement is a supply of glycine, proline and hydroxyproline to that pool, and a supply is not a signal.

Why supply does not drive a keloid, what the literature does and does not say, the three-part honest answer, and the worked example

The reason supply does not drive a keloid is that a keloid fibroblast is not short of anything. The glycine, proline and hydroxyproline that collagen is made from are among the most abundant amino acids in the body, made by the body itself from other amino acids as well as eaten, and a fed person's amino acid pool contains far more of them than any fibroblast could use; a fibroblast that is overproducing collagen in a keloid is doing so because of the signal it is receiving and over-responding to, not because the supply of raw material has risen, and it would overproduce at the same rate on a diet of eggs, chicken or lentils, all of which supply the same amino acids through the same pool. The same separation answers the scleroderma worry, in which the whole body's fibroblasts are driven by an autoimmune signal, on the scleroderma page, and the body's own overproduction conditions, from keloids through Dupuytren's to frozen shoulder, are set out by site on the producing too much collagen page, all of them signalling conditions in which supply plays no part. What the literature says is consistent with the biology: the keloid pathogenesis and treatment literature, which is large, has not identified dietary protein intake or oral collagen as a cause, a risk factor or an aggravating factor for keloid formation or growth, and the dietary factors it does discuss are speculative and unrelated to protein. What the literature does not say is the other half of the honest answer: no trial has enrolled keloid-prone people and given them collagen supplements to measure what happens to their scars, because no one has had a reason to run one, so there is no direct evidence of safety to point to either, only the absence of any signal of harm in a condition that has been studied for a century and a biology that gives no route by which harm would occur. The collagen safety record in general, trials dosing daily for up to a year with adverse events no different from placebo, is on the is collagen safe page, and none of those trials excluded or reported on keloid-prone participants. The honest answer therefore has three parts and the page gives all three rather than the comfortable two. Nothing in the biology or the literature says no: a keloid is a local signalling problem and eaten collagen is systemic amino acid supply, and the two do not meet. No trial has enrolled keloid-prone people to say yes with data: the reassurance is from mechanism and from absence of any signal, not from a trial designed to find one. And a reader with active or growing keloids, or one facing surgery, a piercing or a procedure at a keloid-prone site, asks the dermatologist treating them before adding any supplement, because that dermatologist knows the scar, its activity and the treatment plan, and because a reader whose keloid changes while taking anything new will want to have had that conversation first; the dermatologist may also have views on the vitamin C and zinc in a collagen capsule, both involved in wound healing at sufficiency and neither a keloid driver, and on the fish source for anyone with a fish allergy. The worked example is 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, at a dose below the 2.5 to 10g skin trials and carrying vitamin C's collagen formation sentence for normal skin function and no scar, keloid or healing claim, with the label read by the reader's dermatologist if keloids are active. Can you take collagen if you have keloids: the biology and the literature give no reason not to, no trial gives a reason to be certain, and the dermatologist who treats the keloids is the person to ask.

What to check on the label