Kids who suck their thumbs are less likely to develop allergies
If you want to help allergy-proof your child, it might be wise to let them have a few "bad" habits like sucking their thumb or biting their nails, at least for a few years when they're young.
That's the finding from new research out of New Zealand, where scientists from McMaster University have discovered that children who suck their thumbs are less likely to be sensitive to allergies.
What's more, the strongest defence against being allergic to things like dust mites, cats, dogs and even airborne fungi is actually being both a thumb-sucker and a nail-biter.
According to Professor Malcom Sears, who assisted the research, this finding provides further evidence that the more bacteria people encounter when they're children, the stronger their immune system will later turn out to be.
"Our findings are consistent with the hygiene theory that early exposure to dirt or germs reduces the risk of developing allergies," said Sears in a press release from McMaster University.
"While we don't recommend that these habits should be encouraged, there does appear to be a positive side to these habits."
To reach this conclusion, the researchers dipped into one of the longest-running studies in New Zealand history, where more than 1,000 kiwi kids were tested for allergies in 1972, and then again in 2004 when they were 32-years-old.
Each of the participants were quizzed as to their habits when they were a child, and asked whether they were a nail-biter, a thumb-sucker, or both (and of course, whether they were a perfect little angel without any trace of bad habits to speak of).
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The results were dramatic – of everyone polled, 31 percent of the children were frequent thumb suckers or nail biters. When those same children turned 13-years-old, 45 percent of them had some kind of allergy, but those who had both "bad habits" only had a 31 percent chance of being allergic to something.
It was speculated that the reason why this occurred was due to the idea to biting your nails or sucking your thumbs would introduce your body to a whole new world of microbial bacteria, primarily because you're tasting everything you touch or hold.
Your immune system then recognises all of these different little strains of bacteria, and begins to build a resistance against them, thus creating something of an allergy "suit of armour" thanks to sticking your dirty hands in your mouth all day long. This is known as the "hygiene theory".
As the researchers explained, people who are very allergy-prone are thought to have something called "atopic sensitization". This is where someone grows up to have one of three specific allergies: eczema (where your skin becomes red and itchy), allergic rhinitis (otherwise known as hayfever) and allergic asthma.
For now, it seems like the researchers don’t want parents to be forcing their children to lick their dirty fingers, but if it's already happening there could very well be a positive consequence later in life.