Synesthesia has overlaps with heightened sensitivity and both have overlaps with chronic pain. All of these phenomenon overlap in me so you can see why I am so interested. It's as though chronic pain is the down side of the see-saw on which synaesthesia is the colourful gift at the highest end (I really wouldn't be without it and the sensory adventures it takes me on) and sensitivity is the mixing pot of both, made up of both pluses and minuses, depending on how challenging these heightened sensitivities make the experience of life. Exploring the sensory soup of these cross-over phenomenon, asking whether we are all born with synesthesia as science is now suggesting and looking into all the potential a deeper understanding of them holds for transforming human experience.
The extreme effects that resulted when two of us revisited eating sugar after a long break from it reminded me that these are the normal outcome of sugar consumption for all people. So the variance isn't in the biological effects but in how much people notice them or have adapted to shield themselves from, or absorb, the backlash (though the resultant health issues are seldom avoided so much as redirected into another form of expression; often a more severe health issue, further down the line). Most people push on through the effects of sugar without really acknowledging that they are there; as I know I did, for years. The more we consume the crazy amount of sugar our modern diet makes almost compulsory and extremely (shockingly) normal, the more we become (ironically) immune to it as the nervous system is pushed over the limit to where it has no choice but to turn down its own sensitivity to everything, even those things we want to experience, in order to cope; like a form of self-created paralysis. Its as though sugar only knows one setting - one that makes us receive more sensation, delivered in the most abrasive way possible and it is more than our nervous system, which longs to experience many things but wants to be way more discerning than that, can cope with. We become over-stimulated...and so we break down or are forced to buffer ourselves like we are under constant attack and, of course, some of us stop feeling at all.