Adding Cocoa to Sucrose: The Effect on Cold Pain Tolerance

Abstract

The sweet taste of sucrose acts as an analgesic, whereas the taste of a bitter substance decreases pain tolerance. The present experiment explores the analgesic effect of a complex taste and asks how adding cocoa, a substance often associated with sweet foods but that has a bitter taste, to a sucrose solution affects cold pain tolerance. The 24 male participants were exposed to Cold Pressor Tests (CPTs) while holding 1 of 3 tastants in their mouths: water, sucrose, or sucrose with cocoa added. After each CPT, participants rated pain intensity and tastant qualities. Intraoral sucrose increased the amount of time that men were able to leave their hands in cold water, whereas the cocoa solution did not. Solutions did not differ in pleasantness or sweetness, but the cocoa solution was rated as more bitter. Bitterness ratings of cocoa exceeded the ratings of sucrose (corrected for water) by an average of 16.9% (P = 0.02), which, in turn, produced a 30% reduction in the duration of pain tolerance (P = 0.002). These results suggest that the addition of a bitter substance reduces cues to the nutritive value of sucrose that may drive its analgesic effect.

Cocoa Agronomy, Quality, Nutritional, and Health Aspects

“…The results suggest that taste qualities, probably due to their values as a signal for nutrition, are responsible for mediating cold pain tolerance Eggleston et al (2010) Administration of flavanol-rich cocoa powder and spirulina…”

Chocolate and Pain Tolerance

“…Through learning, chocolate's palatability and perceived pleasantness can become associated with increased levels of endogenous opioids [ 22 ] that may reduce pain perception. Furthermore, the increase in opioids may serve as a self-preservation function, since consuming a food of high nutritional value such as chocolate may be more evolutionarily important to an animal than a brief response to pain [ 18,37 ] .…”

“…It is worth mentioning, however, that chocolate's analgesic effects have not always been observed in humans. At least one study has observed that cocoa's addition to sucrose reduced pain tolerance in a cold-pressor test [ 18 ] . Still, given the number of historical and modern reports of the pain-relieving and medicinal properties of chocolate, it is worth examining the potential mechanisms that could contribute to chocolate analgesia.…”

“…Numerous studies have shown that the sweet taste of sucrose increases pain tolerance [ 18,32,33 ] , particularly in people with high-sweet preferences [ 34 ] , while the taste of bitterness decreases pain tolerance [ 18,33 ] . The administration of opioid antagonists (in humans) reduces preference for the taste of sweetness [ 35 ] , implicating the involvement of the opioid system in the consumption of sweet foods.…”

“…The administration of opioid antagonists (in humans) reduces preference for the taste of sweetness [ 35 ] , implicating the involvement of the opioid system in the consumption of sweet foods. Although it is possible that the association with sucrose is responsible for the analgesia associated with chocolate, sucrose analgesia in a cold-pressor test has been shown to be impaired by the addition of cocoa [ 18 ] . The reduction in analgesia is possibly because, in this experiment, the nutritive taste information transmitted from the sweetened cocoa beverage was complex; the bitter qualities of the cocoa were obvious and contradicted the sweet nutritive cues of sugar, decreasing cold pain tolerance as compared to a plain sucrose solution [ 18 ] .…”