Editor's note: This popular story from the Daily Briefing's archives was republished on Jul. 31, 2023.

Body posture can have an "immense effect" on how quickly medicine is digested and begins working, and changing positions can help those who are "bedridden, elderly" take their medications more easily, according to a new study published in Physics of Fluids.

Study details and key findings

For the study, researchers from Johns Hopkins University created a computer model called "StomachSim" that used physics, biomechanics, and fluid mechanics to mimic what occurs inside a stomach as it digests food or medicine.

According to the researchers, most medication does not start working until it reaches the intestine. This means that the closer a pill is to the antrum, or the lower part of the stomach, the faster it will dissolve and enter the small intestine. Due to gravity and the stomach's asymmetrical shape, a person's posture can significantly impact where a pill lands in the stomach, and thus how quickly it can dissolve and begin working.

Using their model, the researchers tested four body positions—standing upright, lying straight back, lying on the right side, and lying on the left side—and recorded the time it took a pill to dissolve after being taken in each position.

Overall, researchers found that lying on the right side allowed a pill to reach the deepest part of the stomach and dissolve more quickly. It took 10 minutes for a pill to dissolve when an individual was lying on their right side.

"Your stomach is very asymmetrical. It's a bean-shaped organ that curves toward the right of our body," said Rajat Mittal, the study's lead researcher. "And that asymmetry, combined with gravity, has a huge impact on the way the body moves."

In comparison, it took 23 minutes for a pill to dissolve when a person was standing upright or lying straight back, and over 100 minutes when a person was lying on their left side.

"If you are somebody who is bedridden, elderly … you definitely don't want to be on the left hand side because that could slow down the rate at which the pill dissolves and affects your body by a factor of 10 or more," Mittal said.

Commentary

According to Mittal, the researchers were "very surprised that posture had such an immense effect on the dissolution rate of a pill."

"I never thought about whether I was doing it right or wrong but now I'll definitely think about it every time I take a pill," he said.

The findings also apply to how food is digested—something to consider when sleeping after eating a big dinner, Mittal added.

In addition, the researchers noted that even small changes in stomach conditions could significantly affect drug dissolution, such as when someone's gut isn't functioning properly due to diabetes or Parkinson's syndrome, for example. According to Jae Ho "Mike" Lee, a former postdoctoral researcher at Johns Hopkins and the study's lead author, even small changes in the stomach can significantly affect how drugs dissolve.

"Posture itself has such a huge impact, it's equivalent to somebody's stomach having a very significant dysfunction as far as pill dissolution is concerned," Mittal said.

In the future, the researchers said they plan to study how food digestion and posture can affect different diseases, such as obesity and diabetes, as well as intestinal infections and nutrition. (Gentzler et al., NBC4 Washington, 9/2; Rosen, Johns Hopkins University, 8/16; Murez, HealthDay News/U.S. News & World Report, 8/17)