Can gravity make people sick?

Bad things happen to the human body in zero gravity. Just look at what happens to astronauts who spend time in orbit. bones decay. Muscles weaken. Immunity too. “When you go up into space,” says Said Mekari, who studies exercise physiology at the University of Sherbrooke in Canada, “it’s an accelerated model of aging.” Experiments simulating weightlessness on Earth have revealed similar effects. In the 1970s, Russian scientists immersed volunteers in bathtubs covered with a large sheet of waterproof fabric, allowing them to swim without getting wet. In some of these studies, which lasted up to 56 days, subjects had serious heart problems and struggled to control their posture and leg movements.

Weightlessness hurts us because our bodies are well adapted to gravity as we experience it here on Earth. It carries us from birth to death, and yet our bowels are tightly coiled in their pile, the blood flows upward, and our spine is able to support our head. Unnatural contractions can throw things. people have died from hanging upside down for too long. But as a general rule, the constant pressure of g-force on our bodies is a part of life that we rarely notice.

Or at least that’s what scientists think. But there is another possibility: that gravity himself makes some people sick. A new, revised theory suggests that the body’s connection to gravity may go haywire, causing a disorder that has long been a vexing mystery: irritable bowel syndrome.

It’s a rogue idea that’s far from widely accepted, though one that at least some experts say can’t be dismissed outright. IBS is a very common condition that affects about 15 percent of people in the United States, and the symptoms can be severe. People with IBS experience abdominal pain and gas, feel bloated, and often have diarrhea, constipation, or both. But the exact cause of IBS has not been identified. There is evidence behind many competing theories, such as early life stress, diet, and even intestinal infections, but none has emerged as the sole explanation. It is a problem for patients. it’s hard to treat a condition when you don’t know what to target.

Brennan Spiegel, a gastroenterologist at Cedars-Sinai Medical Center in Los Angeles, has a different idea. People with IBS are hypersensitive to gravity as a result of a number of factors: stress, weight gain, altered gut microbiome, poor posture. sleep pattern or other behavior or injury. He got the idea after watching a bedridden relative in a nursing home develop the classic symptoms of IBS. “We are straight organisms,” he told me. “We really shouldn’t be lying around that long.” The hypothesis, which was published late last year The American Journal of Gastroenterology, that’s it, a hypothesis. Spiegel has not conducted any experiments or patient surveys that point to our body’s “misalignment” with gravity as the cause of IBS, even though the mechanisms are based on solid science. But part of what makes the theory so appealing is that it can encompass all the other conventional explanations for disease. “It’s meant to be a new way of thinking about old ideas,” he said.

So exactly how Will someone’s relationship with gravity deteriorate? Consider serotonin, a chemical that carries messages from the brain to the body. Spiegel sees serotonin as an “antigravity agent” because it plays a role in many important bodily functions that affect g-force, such as blood flow. Serotonin can cause blood vessels to constrict, slowing circulation. It can cause certain muscles to contract or relax. It’s also important for digestion, helping with bowel function, getting rid of irritating foods, and regulating how much we eat. Without serotonin, gravity would turn our gut into a “flabby sack,” writes Spiegel. Since 95 percent of serotonin in the body is produced in the gut, if its levels rise or fall due to factors such as stress, gravity’s potential management of the chemical will be thrown into chaos, affecting digestion. The result, he says, is IBS.

Other parts of our bodies that respond to gravity can also be at issue. We are ready to react negatively to situations where gravity can harm us; walk to the edge of a cliff and your body will tell you something. Our brain’s amygdala plays an important role in fear responses, and various types of stress can cause it to become overactive. Spiegel believes that when stress taxes the amygdala, a person begins to overreact to potential threats, including gravity. The digestive problems that make up IBS are a manifestation of that overreaction. Certainly, people with IBS have a hyperactive amygdala.

It’s hardly close to proof. The idea that this painful and long-lasting condition could be a gravity problem is a big deal, based on a denialist interpretation of basic biology. “People just think I’m crazy,” Spiegel said. Most of his fellow doctors aren’t sold on the idea. The gravity hypothesis is just another in a long line of unconvincing theories about IBS, UCLA gastroenterologist Emeran Mayer told me. He heard everyone. “It does not exist. it is the hysterical characteristic of neurotic housewives; it’s abnormal electrical activity in the colon.” He added: “I don’t think there’s any other disease that has gone through this culmination of attention-grabbing new theories.”

Spiegel’s idea has clear holes. If the wrong reaction to gravity is causing IBS, says David K. Kunkel, a gastroenterologist at UC San Diego, then you should expect to see higher rates of IBS in a population living at sea level than at high altitudes, where the g-force is a little weaker. . But it seems that it is not so. about a quarter of Peruvians live in high mountains and most Icelanders live at sea level, but both countries have high rates of IBS. Similarly, rates of IBS appear to decrease with age, “which would not be expected if the disease were caused by constant gravity,” Kunkel told me.

Spiegel is aware that the gravity hypothesis has little support in the field and no evidence. But the gravity hypothesis has some logic behind it. The fact that the weightlessness of space travel can dramatically change the body lends credence to the idea that other changes to our relationship with gravity can do the same, says UC Riverside biomedical scientist Declan McCall.

And the intestines can be particularly sensitive to changes in gravity. McCall found that weightlessness makes it easier for the epithelial cells that line the gut and prevent invaders from entering the body to escape. So if our internal chemistry can change to make us hypersensitive to gravity, it makes sense to McCall that such a shift could hit the gut hard. He’s less sure if that hypersensitivity exists. If so, why haven’t we discovered any chemicals that help regulate attraction like we do with fear, sex drive, or hunger? That molecule may indeed turn out to be serotonin, but there is no evidence at this time.

The gravity hypothesis is only really important if it makes sense to people with IBS. And it’s not guaranteed. Associating the real pain of IBS with such a fantasy can seem closer to mythology than medicine, leaving sufferers feeling dismissed or humiliated. Or they can throw up their hands in despair and brace themselves for a lifetime of pain;

But if there is some truth to it, the hypothesis could also provide a possible starting point for treatment. Some of Spiegel’s recommendations are already popular, such as weight loss and drugs that lower serotonin, but he also advocates some specific treatments for weight gain. “I talk about it with my patients,” Spiegel said. “I recommend certain yoga positions. I recommend tilting tables.” People who have IBS may reject its more radical ideas, such as higher altitude or moving further from the equator.

A hypothesis of gravity can never be more than a hypothesis. We still have a long way to go before we really know whether the human body can develop a hypersensitivity to gravity that can make us sick, or whether some of us are better equipped to handle gravity than others. But the weight of the evidence is enough to make us think twice before dismissing the idea that our body’s relationship with gravity might be out of whack, including those of us who don’t overcome IBS. If gravity can contribute to IBS, why not other ailments? And then, why not put it to good use, too? Mekari and colleagues recently found that lying at a six-degree downward angle speeds up reaction times on cognitive tests, suggesting a possible link between gravity and executive functioning. Antigravity treadmills, which help astronauts prepare for weightlessness, are being studied for treating cerebral palsy, Parkinson’s disease and sports injuries.

All these unknowns about gravity can be haunting. Life on Earth has changed a lot since its first forms appeared about 4 billion years ago, but through it all, gravity seems to have remained the same, perhaps the one thing that binds every organism that has ever lived. What if there is still so much we need to learn about what it does to us? After all, right now your body is defying gravity, just as it has been every second second of your life. Perhaps it would be even stranger if gravity was not doing something with us over time. “Every fiber in our body is straining to handle this force,” says Spiegel. You don’t need to spend 56 days in the bathroom to find out.

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