It is known that nausea is a negative sensation that arises when a person takes in a toxin or a poison. Specifically, it is seen that plant poisons are bitterer in taste. The authors of this study associate the bitterness of plant-derived poisons and feelings of nausea after accidental poisoning with these agents. In this study, they found that the actual activity of the intestine of the volunteers who took in a bitter plant-derived poison made them feel even more nauseous. They conclude that eating something bitter can induce nausea in healthy people.
The feeling of nausea is an unpleasant sensation for people. It is noted that a person taking in a bitter tasting toxin commonly derived from plants feels nauseous. The authors of this study speculate that there is a link between the bitter taste of a food or plant toxin and the feelings of nausea experienced by a person. However, they add that no specific studies have been conducted that explore this association between bitter taste and nausea. The theory is supported by other facts such as “people who are the most sensitive to bitter stimuli are more prone to motion sickness” and pregnancy-induced nausea arising due to bitter taste sensitivity. The latter is supposed to be a natural mechanism that protects the unborn baby from poisoning. Studies have also shown that taking something bitter slows the motions of the intestine. The bitter taste is felt by nerves that are connected to the intestines as well as the back wall of the mouth. This study was undertaken to establish this link in healthy participants.
- For this study, the researchers chose 63 healthy subjects who continued fasting for four hours. All the subjects were given non-toxic bitter solutions to taste. Nausea was also induced by placing the subjects inside a rotating drum that had alternate white and black stripes. As a control measure, they were also given sweet solutions to taste.
- Thereafter, all the subjects were given specific questionnaires that assessed their feelings of nausea, queasiness, weakness of the stomach, and churning of the stomach.
- Simultaneously, tests were conducted to see the rate of movements of their intestines in response to the bitter taste.
- The results showed that out of the 13 subjects who were placed within the rotating drum, 12 subjects experienced nausea similar to motion sickness. On further tests, these subjects also showed changes in their intestinal movements.
- When the subjects were given bitter solutions to taste, they had similar changes in intestinal movements as in the case of the rotating drum. They also complained of nausea when they responded to the questionnaires.
- The changes in the intestinal movements were not seen when the subjects took sweet solutions.
This study shows that intestinal movement and activity is directly linked to a person’s sensation of nausea and further supports literature that shows an association between taking in bitter toxins, feeling nauseous, and slowing down of gut movement. This is the first such study to establish this link clearly in healthy subjects. The authors speculate that just as the gut anticipates a good fare and increases its movement rate, a bitter tasting substance prepares the body “to contain, repel, and punish our ingestion of anti-nutrients or toxins.” They do this by stimulating an anti-propulsive or vomiting tendency to expel the toxin.
For More Information:
Bitter Taste Induces Nausea
Publication Journal: Current Biology
By Catherine Gachons; Gary Beauchamp
From the Monell Chemical Senses Center, Philadelphia, PA
*FYI Living Lab Reports Are Summaries of the Original Research.