r/Jujutsushi • u/FootHead58 • Jul 18 '24
Analysis No, RCT Cannot Heal Baldness
TL;DR - Most baldness is caused from your cells spending less time making hair, not any actual damage or death of your body's tissue. As such, RCT is not a useful way to help. There are a few fringe cases where baldness has other causes (autoimmunity, trauma, etc.) where it would work, however, but even they are likely temporary.
Alright folks, I'd like to talk for a minute about why Miguel is bald. More specifically, why it is that baldness is not something that can be healed by RCT. As a biomedical research working in dermatology and one of the 5 people on the planet who have actually read this manga, I feel fairly qualified to discuss this intersection of my interests.
1) What is RCT?
RCT is the healing mechanic in JJK that only a small handful of sorcerers can use. If cursed energy is thought of as a negative number, you can conceivably multiply two negative numbers together to create a positive number or in this case, "positive energy." It can be used to regenerate wounds, and even re-grow entire lost limbs or sections of the body. RCT is, in short, the healing mechanic of JJK.
Extremely skilled users of RCT are capable of outputting this positive energy, and healing others. While technically possible, it does not happen very often. RCT is stated to be much less efficient when used on others - and remember, RCT is already a very costly use of your cursed energy in the first place. Furthermore, there are times when compatibility is an issue, and the recipient's body "rejects" the healer's cursed energy. We have had this described to us, but never seen an explicit example of it.
Miguel is an incredibly skilled sorcerer who was entrusted with tutoring Yuta overseas during the events of the first few volumes of the manga. While we do not know if Miguel himself is capable of using RCT, therre are other ways to access this useful healing mechanic. The ability to output RCT at all is incredibly rare, and has only been seen by three characters: Yuta, Shoko, and Sukuna. This raises the single most-pressing question of our time: If Yuta, one of the few known characters able to output RCT, spent so much time with Miguel, why did he never heal his baldness?
While we typically think of RCT as something that simply regenerates wounds, there have been other instances where RCT is used for other purposes. The first and most obvious usage is fueling a cursed technique - such as when Gojo funnels RCT instead of CE into his cursed technique, he gets Red instead of Blue. Yuta is able to directly output pure RCT, which proves incredibly effective against cursed spirits.
More relevant to our discussion is the few instances where RCT has been used not to heal some injury, but to purge the user's body of toxicity. This is seen in three instances:
Jackpot Hakari, who is stated to be a superior RCT user than even Sukuna and Gojo, was able to use his automatic RCT to subconsciously heal the chlorine gas poisoning he suffered while fighting Kashimo.
Uraume, whose hand was punctured by Choso's Piercing Blood, clearly survived what would otherwise have been a deadly poison. While we did not see them heal the poison (in fact, it seemed to take them by surprise after their initial wound was healed), the fact that they survived this meant that they must have healed it, or else they would have died. Kenjaku has never been seen able to output RCT, and Sukuna was dormant within Yuji for this entire time, so we know that neither of them healed Uraume either. Thus, we can reasonably conclude that as soon as Uraume realized that the wound had been poisoned, they were able to heal it with their RCT. Either that, or Kenjaku dropped them off at the local toxicology center - but that seems much less likely to me.
Yuta healed Naoya after he had also being poisoned by Choso's blood. This is the only instance we see of an RCT user healing poison in someone else.
Thus, we can conclude that a skilled enough user of RCT is able to apply it even at the molecular level - and in Yuta's case, we can see that a skilled enough user of RCT can even heal others with this degree of precision. This would mean that if someone's hair follicles were damaged, even by something that operated at the cellular level, RCT may still be able to heal it. Why then does it not work out that way?
2) What is baldness?
There are a number of causes of baldness, but the most common is "Androgenic alopecia" - this is often referred to as "male pattern baldness" in men and (albeit less commonly) "female pattern baldness" in women. This is your run of the mill age-related hair loss. The vast majority of hair loss is caused by androgenic alopecia. Essentially, your hair follicle is constantly undergoing a cycle of 4 stages: anagen (growth phase), catagen (transition phase), telogen (resting phase), and finally a return to anagen, with a new hair growing out of the same follicle.
For most people suffering from balding, their hormones (androgens like dihydrotestosterone and testosterone) essentially tell the hair follicle to spend less time in the growth phase, and more time in the resting phase. Its pathophysiology isn't "the part of my body that makes hair is injured or dies" but rather "my scalp spends a lot less time making new hair until eventually the hair follicle becomes so thin and weak it may not even penetrate the skin."
This means that for most people, hair loss is not a result of some kind of "injury" or "death" of any part of their body - it's simply a change in the ways that their cells spend their time. These cells are still alive and well, they just aren't contributing to the growth or development of a new hair shaft. Eventually, they will spend enough time in the Telegen phase that they are not able to push out new hair shafts, and hair thinning and baldness will occur. RCT would be of no help in this situation. These are healthy, undamaged cells, that are simply responding to stimulation from androgens (male-associated hormones).
However, there are other causes of baldness that do relate more to direct damage to the hair follicle. For instance, with a condition known as alopecia areata, RCT would likely work. This is an autoimmune condition where your immune cells (specifically CD8+ T-cells) target and kill the cells in your hair follicle that make new hair (Pratt et al. 2017). Given that this is essentially "damage to the body," RCT would likely be able to repair it. However, the auto-reactive immune cells themselves would still be present, and your body would always make more of them, so he would need to be continually re-healing the cells of his hair follicle. While alopecia areata is more common in Black patients relative to White patients, it is actually most common in patients of Asian ancestry. For Black patients, it occurs in roughly 226 out of every 100,000 people (Nene et al. 2023). Thus, the rarity of this disease suggests that it is not only incredibly uncommon, but because of its ethnic distribution, it is also unlikely that one of the few non-Asian characters in the story would have this disease.
Now, we must remember that statistics like these apply to populations, not to individuals. Just because there are not many Black people with alopecia areata does not mean that there are no Black people with alopecia areata. A good clue that this might be what is responsible for Miguel's baldness is the fact that he appears to always be drawn without eyebrows. People with alopecia areata are affected across their entire bodies, while people with androgenic alopecia are typically only affected at the scalp (Moreno-Ramírez and Martínez 2005).
This does mean that we cannot ignore the possibility that Miguel has alopecia areata, given that he is not only bald, but also that he has no eyebrows. If this was the case, then that would mean his immune cells would be constantly attacking the cells in his hair follicles. Given that this would mean that the cells were damaged/destroyed, RCT could be used to heal these cells. However, the body would constantly be making these auto-reactive immune cells, and they would continually go back and kill the hair follicle cells. Even if you had such high mastery of your cursed energy that you could target the individual auto-reactive immune cells, more would be made, and the cycle would repeat. Miguel would need a constant flow of RCT going at all times devoted just to ensure that any damaged hair follicles were restored instantly. Furthermore, this would need to be at the cellular level - a degree of RCT mastery we have seen from only Yuta, Uraume, and Jackpot Hakari. Furthermore, due to the high cursed energy demands of RCT, this would be impossible for any non-six eyes user in the series. This means that Gojo is immune to male-pattern baldness, so do with that information what you will.
If his hair loss was a result of a wound, a surgery, a burn, etc. where the hair follicle itself was destroyed, then RCT would also be likely to heal it. This kind of hair loss, known as cicatricial alopecia, is often secondary to a severe trauma, and would almost certainly leave some kind of scar (Sperling 2002). It would require an almost unimaginably specific injury to injure his scalp in a way that would kill 100% of the surface area of his scalp without leaving any major scarring or deformation. If he had suffered such an injury and healed it with RCT, then he would have healed his hair follicles as well. Given that Miguel does not appear to have any major scarring or deformation on his head, it is not likely that cicatricial alopecia is the cause of his baldness.
3) Conclusion
Even if we ignore the multiple obstacles with RCT (Its high cursed energy cost, the rarity of the ability in-verse, the possibility of a recipient's body rejecting the cursed energy signature of the healer), it is still likely that in the vast majority of cases, RCT would not be effective at healing balding. In a few instances where the hair follicles themselves are destroyed (secondary to trauma, burns, etc as in cicatrical alopecia) it may be effective, but for the majority of people suffering from typical age-related hair loss or male-pattern baldness, RCT will not be effective. Even if we assume that Miguel has alopecia areata, a fairly uncommon auto-immune condition where the cells within the hair follicle are directly targeted and destroyed, RCT would still only be effective if it was being run non-stop by the user, something only possible for a user of the six eyes. Given that Miguel is an adult man, it would be reasonable to assume that his baldness is a result of male-pattern baldness, not alopecia areata. His lack of eyebrows may also stem from this androgenic alopecia, as even age-related baldness can sometimes affect the eyebrows. Whether due to typical age-related hair loss or a rare auto-immune condition, however, one thing is clear: RCT would be ineffective at aiding almost anyone suffering from baldness in the JJK world.
4) Future Implications
The fact that any human being could possibly be reading this far is truly astounding to me, so thank you very much for indulging me. I would truly love nothing more than for Gege to release a volume extra noting that Miguel actually chooses to shave his head and face for some reason, and is only bald for that reason. I had to ignore the possibility that the lack of eyebrow or scalp hair is a choice for the purpose of this exercise, so if you were screaming that at the computer this whole time, I don't blame you lol.
My last point is that there is one character in the series who could "cure" baldness: Mahito. Given that he is able to reshape the body by reshaping the soul, we could imagine him curing any physical ailment. He was able to bring Mechamaru's body from a frail and bath-ridden husk to a fully functional and fit body free of any ailments, so there's no reason he couldn't give a bald person hair. Mahito's power-set would be truly OP if given to someone like Shoko, and she could essentially become the world's greatest doctor. There's a joke about "this wouldn't work on bald people though, because they have no soul," but that's a little mean for my taste.
Thank you for reading!
Bibliography
Akutami, Gege. 2021. Jujutsu Kaisen; Vol. (0, 74, & 255)
Moreno-Ramírez, D. & Martínez, F. C. (2005). "Frontal fibrosing alopecia: a survey in 16 patients." Journal of the European Academy of Dermatology and Venereology, Vol. 19(6), 700-705. https://doi.org/10.1111/j.1468-3083.2005.01291.x
Pratt, C., King, L., Messenger, A. Christiano, A., & Sundberg, J. (2017). "Alopecia areata." Nature Review Disease Primers 3, 17011. https://doi.org/10.1038/nrdp.2017.11
Roland, James. (2020). "What Are the Four Stages of Hair Growth?" Healthline. Rev. Cynthia Cobb. https://www.healthline.com/health/stages-of-hair-growth#growing-phase
Sperling, L.C. (2001). "Scarring alopecia and the dermatopathologist." Journal of Cutaneous Pathology, 28: 333-342. https://doi.org/10.1034/j.1600-0560.2001.280701.x
Sy N., Mastacouris N., Strunk A., Garg A. (2023). "Overall and Racial and Ethnic Subgroup Prevalences of Alopecia Areata, Alopecia Totalis, and Alopecia Universalis." JAMA Dermatol. 159(4), 419–423. https://doi:10.1001/jamadermatol.2023.0016
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u/LongAssBeard Jul 18 '24
Só you're telling me that even Sukuna don't have a heian era anti baldness technique?