Comment on That's normal, right?
finitebanjo@lemmy.world 6 days agoSpace nutrition and the biochemical changes caused in Astronauts Health due to space flight: A review Angel Dakkumadugula, Lakshaa Pankaj, Ali S Alqahtani, Riaz Ullah, Sezai Ercisli, Rajadurai Murugan
PMCID: PMC10740090 PMID: 38144801
Food Chem X. 2023 Sep 15;20:100875. doi: 10.1016/j.fochx.2023.100875
7.3. Abnormal digestion and absorption
Digestion and absorption are disturbed due to microgravity primarily because the absence of gravity alters the normal functioning of the gastrointestinal system. In microgravity, the absence of gravitational forces significantly impacts the motility of the gastrointestinal tract. Peristaltic movements, which help propel food through the digestive system, are diminished or altered. This can result in slower transit times and inefficient movement of food through the digestive tract, leading to digestive disturbances (Yang et al., 2020).
In microgravity, fluids in the body shift towards the upper body, causing fluid volume changes and redistribution. This can result in a decrease in blood volume and an increase in fluid accumulation in the head, leading to a condition known as “puffy face syndrome.” The altered fluid dynamics can affect the function of the digestive system. Microgravity can disrupt the normal functioning of the stomach, leading to gastrointestinal discomfort and gastric upset.
The gut microbiome, the community of microorganisms in the gastrointestinal tract, plays a crucial role in digestion and nutrient absorption. Microgravity can lead to changes in the composition and diversity of the gut microbiome, which can impact the breakdown and absorption of nutrients. These alterations may also contribute to gastrointestinal issues and nutrient deficiencies. Due to the effects of microgravity on digestion and absorption, astronauts may have altered nutritional requirements. Nutritional supplements and meal plans are designed to meet the unique needs of astronauts during space missions (Yang et al., 2020, Amidon et al., 1991).
Amidon G.L., Gary A., DeBrincat N.N. Effects of gravity on gastric emptying, intestinal transit, and drug absorption. Journal of Clinical Pharmacology. 1991;31:968–973. doi: 10.1002/j.1552-4604.1991.tb03658.x.
Yang J.-Q., et al. The effects of microgravity on the digestive system and the new insights it brings to the life sciences. Life Sciences and Space Research. 2020;27:74–82. doi: 10.1016/j.lssr.2020.07.009.
ameancow@lemmy.world 5 days ago
This is all true but not the “rule” and no part of any of these studies says that digestion is “gravity based” and in fact many astronauts have no problem with their digestion. Some do, some don’t. Space and microgravity can exacerbate issues and cause acid reflux for all the reasons cited, but again, not the rule, and most astronauts adapt. UK astronaut Tim Peake has given talks about how you feel full faster because the lack of gravity’s “tug” but otherwise, as this paper describes, the primary force for pushing food down and through your winding tubes is peristalsis, in some people this action is strong enough for astronauts or burrito-eaters to not feel ANY ill effects eating and then changing orientation, in some people, everything flies right out both ends.
Either way, most bodies adapt to conditions they’re in regularly, and it’s just wrong to characterize digestion as reliant on gravity and an upright position, or eating before bed as leading inevitably to “irritable bowels, and leaky butthole, hemorrhoids and bloody stool.”
finitebanjo@lemmy.world 5 days ago
I’m glad you reversed your stance after being presented the facts, thank you for being reasonable.
ameancow@lemmy.world 5 days ago
Oh, so you’re not having a conversation but you’re in fact unhinged. I see now. Have a good one. blocked.
finitebanjo@lemmy.world 5 days ago
You said it wasn’t gravity based, cited space travel, I provided evidence directly contradicting you and you said “yes thats all true, but [paragraph] [paragraph]”