A new study proves parachutes are useless

A new study flies in the face of anecdotal evidence and raises questions about how we read data.

  • Scientists working at medical schools across the United States discovered that parachutes don't lower the death rate of people jumping out of airplanes.
  • The study flies in the face of decades of anecdotal evidence.
  • The findings should be carefully applied, due to "minor caveats" with the experimental structure.

There is an old joke that says "If your parachute doesn't deploy, don't worry: you have the rest of your life to fix it." The findings of a new study may put that joke out of fashion, as intrepid scientists found that jumping out of a plane with a parachute didn't lower the death rate of test subjects compared to those who jumped without one.

A leap of faith in anecdotal evidence

The study, published in the light-hearted Christmas edition of BMJ, involved 23 test subjects who were randomly sorted into two groups. One would leap out of an airplane with a parachute while the second would do the same with a regular old backpack. Their survival rates were then compared after they hit the ground. Shockingly, it was found that the rates were the same for both groups!

The authors explained that "Our groundbreaking study found no statistically significant difference in the primary outcome between the treatment and control arms. Our findings should give momentary pause to experts who advocate for routine use of parachutes for jumps from aircraft in recreational or military settings."

What? How!?!

Yeh et al.

A portion of the flow chart explaining the study structure. As you can see, it follows every regulation for a randomized trial with a control group.

In order to get people to agree to take part in the study, the scientists had to structure the experiment properly. The airplane was both on the ground and stationary, as they thought it would be impossible to get people to agree to leap from a moving plane several thousand feet up without a parachute. The authors admit this was a "minor caveat" in the study's design.

They don't admit this until the fourth or fifth paragraph into the paper, however, which leads to their larger point.

Beware of headlines

The authors explain that the whole study was designed to highlight the limitations of randomized trials and the dangers of not reading past the first paragraph of a study. They explain:

"The parachute trial satirically highlights some of the limitations of randomized controlled trials. Nevertheless, we believe that such trials remain the gold standard for the evaluation of most new treatments. The parachute trial does suggest, however, that their accurate interpretation requires more than a cursory reading of the abstract. Rather, interpretation requires a complete and critical appraisal of the study. In addition, our study highlights that studies evaluating devices that are already entrenched in clinical practice face the particularly difficult task of ensuring that patients with the greatest expected benefit from treatment are included during enrollment."

While this study is funny, the questions it raises are real ones. Many influential studies in psychology have been found to be flawed because they used W.E.I.R.D test subjects or were applicable only to a limited range of situations. By clearly showing how accepted procedures can be used to create an absurd little paper, the authors remind us to look closely at the findings of any study.

Admit it, you've read a headline before and then pretended like you read the whole article later when you wanted to talk about it. The point of this silly study is to show just how misleading a summation of a study can be and how important context is in understanding what experiments mean. So have a laugh, and remember to always read more than the study's abstract before you decide to take its supposed findings to heart.

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An organism found in dirt may lead to an anxiety vaccine, say scientists

Can dirt help us fight off stress? Groundbreaking new research shows how.

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  • New research identifies a bacterium that helps block anxiety.
  • Scientists say this can lead to drugs for first responders and soldiers, preventing PTSD and other mental issues.
  • The finding builds on the hygiene hypothesis, first proposed in 1989.

Are modern societies trying too hard to be clean, at the detriment to public health? Scientists discovered that a microorganism living in dirt can actually be good for us, potentially helping the body to fight off stress. Harnessing its powers can lead to a "stress vaccine".

Researchers at the University of Colorado Boulder found that the fatty 10(Z)-hexadecenoic acid from the soil-residing bacterium Mycobacterium vaccae aids immune cells in blocking pathways that increase inflammation and the ability to combat stress.

The study's senior author and Integrative Physiology Professor Christopher Lowry described this fat as "one of the main ingredients" in the "special sauce" that causes the beneficial effects of the bacterium.

The finding goes hand in hand with the "hygiene hypothesis," initially proposed in 1989 by the British scientist David Strachan. He maintained that our generally sterile modern world prevents children from being exposed to certain microorganisms, resulting in compromised immune systems and greater incidences of asthma and allergies.

Contemporary research fine-tuned the hypothesis, finding that not interacting with so-called "old friends" or helpful microbes in the soil and the environment, rather than the ones that cause illnesses, is what's detrimental. In particular, our mental health could be at stake.

"The idea is that as humans have moved away from farms and an agricultural or hunter-gatherer existence into cities, we have lost contact with organisms that served to regulate our immune system and suppress inappropriate inflammation," explained Lowry. "That has put us at higher risk for inflammatory disease and stress-related psychiatric disorders."

University of Colorado Boulder

Christopher Lowry

This is not the first study on the subject from Lowry, who published previous work showing the connection between being exposed to healthy bacteria and mental health. He found that being raised with animals and dust in a rural environment helps children develop more stress-proof immune systems. Such kids were also likely to be less at risk for mental illnesses than people living in the city without pets.

Lowry's other work also pointed out that the soil-based bacterium Mycobacterium vaccae acts like an antidepressant when injected into rodents. It alters their behavior and has lasting anti-inflammatory effects on the brain, according to the press release from the University of Colorado Boulder. Prolonged inflammation can lead to such stress-related disorders as PTSD.

The new study from Lowry and his team identified why that worked by pinpointing the specific fatty acid responsible. They showed that when the 10(Z)-hexadecenoic acid gets into cells, it works like a lock, attaching itself to the peroxisome proliferator-activated receptor (PPAR). This allows it to block a number of key pathways responsible for inflammation. Pre-treating the cells with the acid (or lipid) made them withstand inflammation better.

Lowry thinks this understanding can lead to creating a "stress vaccine" that can be given to people in high-stress jobs, like first responders or soldiers. The vaccine can prevent the psychological effects of stress.

What's more, this friendly bacterium is not the only potentially helpful organism we can find in soil.

"This is just one strain of one species of one type of bacterium that is found in the soil but there are millions of other strains in soils," said Lowry. "We are just beginning to see the tip of the iceberg in terms of identifying the mechanisms through which they have evolved to keep us healthy. It should inspire awe in all of us."

Check out the study published in the journal Psychopharmacology.