Several studies indicate that the brain regions responsible for taste overlap the areas responsible for detecting pain.
However, Dana Small and A. Vania Apkarian noted that little research has been conducted on the relationship to taste sensitivity and pain. They developed a simple experiment to see if there was a relationship.
Eleven volunteers with chronic back pain were matched with 11 normal volunteers, of similar age, gender, and education backgrounds. Each person was tested separately for sensitivity to four different kinds of tastes: bitter, salty, sweet, and sour. They each sampled a small cup of water with each of the four flavors, rating them on a scale of 0 to 100 for the strength of the taste sensation. Here are the results:
For salty, sweet, or sour tastes, as well as the overall average, people with chronic back pain rated the flavors as significantly more intense than normal individuals. There's clearly a relationship between these two phenomenona.
But perhaps people with chronic back pain simply rate the flavors as more intense, but aren't actually sensing anything different. Small and Apkarian designed two tests to see if this could explain the discrepancy. In the first, the sour flavor was presented in a highly diluted form, undetectable by all participants. The concentration of flavor was gradually increased until it was detected. Again, there was a trend towards people with back pain detecting the flavor at a lower concentration than normal individuals. Though the trend was not significant, the researchers argue that it suggests that people with chronic back pain are indeed more sensitive to taste.
In the second test, participants were shown cards colored different shades of gray and asked rate their their blackness on a scale of 0 to 100. There was no difference between people with back pain and healthy people, again suggesting that people with back pain aren't merely biased towards more intense ratings.
Small, D.M., & Apkarian, A.V. (2006). Increased taste intensity perception exhibited by patients with chronic back pain. Pain, 120, 124-130.
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That's interesting. My husband definitely fits into that group - he has back pain and can detect small differences in taste that I can't pick up on at all. On the other, I also don't have a good sense of smell and that is most likely why my sense of taste isn't as sensitive as others.
Very interesting... but why did the researchers argue that a non-significant result should be treated as significant? I'm just curious!
Maybe they identify themselves as having back-pain because they are more sensitive to stimuli...?
How would they rate on other tests? Would they rate everything higher? That is, is the "back pain" group self-selecting with a bias to rate everything higher - with people who may have similar back pain simply not rating it as high, and therefore not seeking treatment?
Errr, I mean to say, not necessarily to "rate" epxeriences higher, but to actually experience a stronger response to any stimulus.
Did anyone consider what pain medications the subjects were on during this study? For what it's worth, I suffered a serious injury back in 1999 & I've noticed that my sense of taste changed with certain medicines. The reason I noticed this was due to the fact that I was a chef prior to the accident. I was aware of my sense of taste & referred to it daily. Anyone else experience a loss or strength of certain senses?
I hope to see a study like this done on pain and sensitivity to odors as well as taste. I have chronic back problems, and pain is just a daily feature of life. I have always been more sensitive (at detecting, as well as not tolerating) odors and tastes, often too subtle for others to notice. This was the case even before my back problems started. However I haven't noticed any further increased sensitivity to odor or taste after the onset of back troubles.
I wonder if others have their sensitivities "hypertuned" by the stimulations received (as from pain) which enables them to pick up on tastes earlier.