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Thumb-Sucking and Nail-Biting May Decrease Allergy Risk

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Very little in life is either all good or all bad. The same genes that help protect us from some ailments might make us susceptible to others. Shouting obscenities can alleviate pain. And researchers, who published their findings in the journal Pediatrics, say frowned-upon behaviors like thumb-sucking and nail-biting might actually reduce kids’ risks of developing allergies later in life.

The idea that putting your germ-covered hands in your mouth might be beneficial will come as no surprise to those familiar with the hygiene hypothesis. The theory is that, in this age of hand sanitizer and antibiotics, the absence of germs and other immune-triggering substances in the environment weakens our immune systems and makes them more sensitive. In turn, that sensitivity may be responsible for the modern increase in allergies and autoimmune diseases.

Earlier studies have shown that exposing small children to small amounts of immune triggers from pet dander to germy pacifiers can protect them later in life. It’s been suggested that even booger-eating could pay off in the long run. ("I've got two beautiful daughters and they spend an amazing amount of time with their fingers up their nose," University of Saskatchewan biologist Scott Napper told the CBC in 2013, when he floated the idea of a study about the subject to his students. "And without fail, it goes right into their mouth afterwards. Could they just be fulfilling what we're truly meant to do?”) So imagining a silver lining for other scold-worthy habits was kind of a logical next step.

To find their nail-biters and thumb-suckers, researchers tapped into the Dunedin Multidisciplinary Health and Development Study, which followed more than 1000 residents of Dunedin, New Zealand, from birth to age 38. When the study subjects were 5, 7, 9, and 11 years old, scientists asked their parents about the kids’ thumb-sucking and nail-biting behaviors. When they were 13, the scientists gave them their first skin-prick test, monitoring the kids’ immune responses to tiny doses of 11 different allergens (not including foods or hay fever triggers). At 32, the participants were tested again.

Those pesky habits were unsurprisingly common. From ages 5 to 11, 31 percent (317 kids) regularly sucked their thumbs or bit their nails. Allergies were pretty common, too; at 13, around 45 percent of all the kids displayed some sort of allergic response to the scratch tests. But that number represents an average of all the kids, regardless of behaviors or habits. Splitting the group tells a different story. Kids that didn’t engage in thumb-sucking or nail-biting had a 49 percent chance of developing allergies. Kids that sucked their thumbs or bit their nails had a 40 percent risk. But kids that did both had the lowest allergy risk of all, at 31 percent—an 18 percent reduction.

The patterns held strong into adulthood, even when the researchers controlled for household exposure to smoke, pets, dust mites, and other triggers.

Of course, that doesn’t mean that we should all follow their example. Both thumb-sucking and nail-biting can lead to dental problems and skin infections, after all. Malcolm Sears of McMaster University assisted with the study. "While we don't recommend that these habits should be encouraged, there does appear to be a positive side to these habits," he said in a press statement.

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The Surprising Link Between Language and Depression
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Skim through the poems of Sylvia Plath, the lyrics of Kurt Cobain, or posts on an internet forum dedicated to depression, and you'll probably start to see some commonalities. That's because there's a particular way that people with clinical depression communicate, whether they're speaking or writing, and psychologists believe they now understand the link between the two.

According to a recent study published in Clinical Psychological Science, there are certain "markers" in a person's parlance that may point to symptoms of clinical depression. Researchers used automated text analysis methods to comb through large quantities of posts in 63 internet forums with more than 6400 members, searching for certain words and phrases. They also noted average sentence length, grammatical patterns, and other factors.

What researchers found was that a person's use (or overuse) of first-person pronouns can provide some insight into the state of their mental health. People with clinical depression tend to use more first-person singular pronouns, such as "I" and "me," and fewer third-person pronouns, like "they," "he," or "she." As Mohammed Al-Mosaiwi, a Ph.D. candidate in psychology at the University of Reading and the head of the study, writes in a post for IFL Science:

"This pattern of pronoun use suggests people with depression are more focused on themselves, and less connected with others. Researchers have reported that pronouns are actually more reliable in identifying depression than negative emotion words."

What remains unclear, though, is whether people who are more focused on themselves tend to depression, or if depression turns a person's focus on themselves. Perhaps unsurprisingly, people with depression also use more negative descriptors, like "lonely" and "miserable."

But, Al-Mosaiwi notes, it's hardly the most important clue when using language to assess clinical depression. Far better indicators, he says, are the presence of "absolutist words" in a person's speech or writing, such as "always," "constantly," and "completely." When overused, they tend to indicate that someone has a "black-and-white view of the world," Al-Mosaiwi says. An analysis of posts on different internet forums found that absolutist words were 50 percent more prevalent on anxiety and depression forums, and 80 percent more prevalent on suicidal ideation forums.

Researchers hope these types of classifications, supported by computerized methods, will prove more and more beneficial in a clinical setting.

[h/t IFL Science]

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Just 5 Alcoholic Drinks a Week Could Shorten Your Lifespan
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Wine lovers were elated when a scientific study last year suggested that drinking a glass of wine a day could help them live longer. Now a new study, published in The Lancet, finds that having more than 100 grams of alcohol a week (the amount in about five glasses of wine or pints of beer) could be detrimental to your health.

Researchers from the University of Cambridge and the British Heart Foundation studied the health data of nearly 600,000 drinkers in 19 countries and found that five to 10 alcoholic drinks a week (yes, red wine included) could shave six months off the life of a 40-year-old.

The penalty is even more severe for those who have 10 to 15 drinks a week (shortening a person’s life by one to two years), and those who imbibe more than 18 drinks a week could lose four to five years of their lives. In other words, your lifespan could be shortened by half an hour for every drink over the daily recommended limit, according to The Guardian, making it just as risky as smoking.

"The paper estimates a 40-year-old drinking four units a day above the guidelines [the equivalent of drinking three glasses of wine in a night] has roughly two years' lower life expectancy, which is around a 20th of their remaining life," David Spiegelhalter, a statistician at the University of Cambridge who was not involved with the study, tells The Guardian. "This works out at about an hour per day. So it's as if each unit above guidelines is taking, on average, about 15 minutes of life, about the same as a cigarette."

[h/t The Guardian]

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