Allison asks...Strange questions, but it’s come up often lately. Several cosmetologists and women who dye their hair have indicated that when a client complains that the hair dye tingles or irritates their scalp, the cosmetologist will add 1-2 packets of Nutrasweet (aspartame) to the dye mixture and the effect is minimized. Is this a psychological reaction or does the aspartame interact with the dye chemicals or the peroxide in a way that actually reduces the irritation??
The Beauty Brains respond:
Aspartame (technically known as the methyl ester of the aspartic acid/phenylalanine dipeptide) is a very popular artificial sweetener. We’d never heard of it being used in relation to hair dyes before but, sure enough, a quick web search revealed several examples. Let’s see if this makes any sense from a scientific perspective.
Why are hair dyes irritating?
Before we talk about how to stop irritation, let’s talk about what causes it in the first place. The primary issue with hair dyes (when it comes to irritation) is a chemical called p-Phenylenediamine or PPD for short. PPD is important to hair dyes because it provides darker, longer lasting color. However, because it is reactive, it can cause a condition known as allergic contact dermatitis in some people. According to the Mayo Clinic, the symptoms of contact dermatitis range from a mild red rash to “blisters, draining fluid and crusting.”
Can aspartame stop an allergic reaction?
Let’s be clear about something up front: we are not allergy specialists or immunologists. If there are any medical specialists reading this post who are more knowledgeable than we are, we’d love to hear from you. But based on what we know of the chemistry of the involved ingredients, the idea that aspartame can stop an allergic reaction makes no sense.
Why not? Because for the sweetener to work this way it would have to have one of two potential modes of action. One, it could act as a barrier so the PPD doesn’t penetrate the skin and therefore could not trigger an allergic reaction. But if this were the case it would also stop the PPD from penetrating into the hair. And that means that the quality of hair color would be compromised. Two, the aspartame could penetrate into the skin along with the PPD and interfere with the histamine response that triggers the allergic reaction. But we could find no data suggesting that aspartame behaves in this way. Without any data, or even a plausible mechanism, we have to be skeptical that this trick really works.
The Beauty Brains bottom line
We were unable to find any kind of scientific rationale for mixing aspartame with hair color. Therefore, we believe that doing so is a waste of good sweetener. Furthermore, doing so could give people a false sense of security about hair dye reactions. Artificial sweetener should not be a substitute for doing a patch test to determine whether or not you’ll have an allergic reaction to a color. And remember, once you’ve been sensitized to a color you’re more likely to have a more serious reaction in the future. So don’t rely on aspartame to protect you from that!
Has anyone else heard of this practice? Leave a comment and share your thoughts with the rest of the Beauty Brains community.