WEBVTT - BrainStuff Classics: How Can Your Birth Season Determine Your Allergies?

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<v Speaker 1>Welcome to brain Stuff production of I Heart Radio. Hi

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<v Speaker 1>brain Stuff Lauren boge obam here with a classic brain

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<v Speaker 1>Stuff episode. As we often discuss on this show, human

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<v Speaker 1>bodies are gloriously weird things that science still doesn't entirely understand.

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<v Speaker 1>For example, allergies. They're an immune system response that's influenced

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<v Speaker 1>by everything from our genes to what we're exposed to

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<v Speaker 1>during our first months of life. Today's episode deals with

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<v Speaker 1>how even the season it was when you were born

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<v Speaker 1>can make a difference. Hey, brain Stuff, Lauren bog obam here,

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<v Speaker 1>people born in the fall and winter are more likely

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<v Speaker 1>to have allergies than people born in the spring and summer.

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<v Speaker 1>While that might be news to you, it certainly was

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<v Speaker 1>to me. The scientific community has known about it for years,

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<v Speaker 1>and a recent study published in the European Journal of

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<v Speaker 1>Allergy and Clinical Immunology set out to discover why it happens.

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<v Speaker 1>Many of us have a unique physical identify or maybe

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<v Speaker 1>a noticeable birth mark. We also have certain markers on

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<v Speaker 1>our DNA that can help determine things like our weight

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<v Speaker 1>and height, our mood swings, and even our risk for

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<v Speaker 1>some conditions like schizophrenia. The researchers found out that those markers,

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<v Speaker 1>called epigenetic marks, can help determine whether we're at risk

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<v Speaker 1>for allergies. We spoke with Dr Gabrielle Lockett, lead author

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<v Speaker 1>of the study, via email. She said epigenetic marks are

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<v Speaker 1>a way to regulate the expression of genes without altering

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<v Speaker 1>the underlying DNA sequence. A gene expression is a process

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<v Speaker 1>where information stored in our DNA is translated into instructions

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<v Speaker 1>for making proteins or other molecules. Lockett, who is a

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<v Speaker 1>postdoctoral research fellow in the Faculty of Medicine at England's

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<v Speaker 1>University of Southampton, says that researchers have long known that

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<v Speaker 1>your birth season, as well as certain environmental exposures like smoking, famine,

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<v Speaker 1>or even your social environment, are associated with certain epigenetic

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<v Speaker 1>marks and can alter gene expression. They just didn't know why.

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<v Speaker 1>She said epigenetic marks were a good candidate for the

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<v Speaker 1>connecting mechanism between birth season and allergies because they can

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<v Speaker 1>be altered by environmental exposures, can influence gene expression, and

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<v Speaker 1>can last many years. Lockett and her team scanned DNA

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<v Speaker 1>samples from three hundred and sixty seven eighteen year olds

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<v Speaker 1>who were born on the Isle of Wight in England.

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<v Speaker 1>They paid particular attention to certain markers called DNA methylation

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<v Speaker 1>in the samples. DNA methylation is one type of epigenetic mark.

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<v Speaker 1>Methyl groups help cells reproduce normally, and they can literally

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<v Speaker 1>turn genes on or off. When your methyl groups are depleted,

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<v Speaker 1>bad genes like those that cause cancer are turned on.

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<v Speaker 1>Researchers wanted to know whether certain markers could be linked

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<v Speaker 1>to the time of year a person was born, and

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<v Speaker 1>whether those people experience allergies like xzema or asthma. Lockett said,

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<v Speaker 1>we found that yes, DNA methylation at certain places in

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<v Speaker 1>the genome is consistently associated with season of birth. We

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<v Speaker 1>went on to discover that these birth seasonal epigenetic marks

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<v Speaker 1>are associated with gene expression and could potentially provide a

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<v Speaker 1>link to allergic disease. Luckett says her team found similar

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<v Speaker 1>results when they duplicated the study with a group of

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<v Speaker 1>eight year olds from Holland, but the markers were not

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<v Speaker 1>present when the team tested a group of newborns. Lackett

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<v Speaker 1>says this suggests that epigenetic markers arise after birth or

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<v Speaker 1>maybe even as a result of one's environment. The link

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<v Speaker 1>between birth month, and allergy risk applies to all kinds

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<v Speaker 1>of allergies, Luckett said. For decades, studies have shown that

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<v Speaker 1>people born in autumn and winter are at an increased

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<v Speaker 1>risk of not only rhinitis hay fever, but also food allergy,

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<v Speaker 1>asthma and eczema. She continued, One large Dutch study found

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<v Speaker 1>that people born in ottuman winter were at increased risk

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<v Speaker 1>of having immune responses to non seasonal allergies such as

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<v Speaker 1>egg white and cow's milk, as well as two seasonal

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<v Speaker 1>allergies like pollen, cat dog and house dust mighte. This

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<v Speaker 1>suggests that season of birth is associated with a person's

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<v Speaker 1>risk of allergy in general. The effect is not restricted

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<v Speaker 1>to seasonal allergies. So why would your birth month affect

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<v Speaker 1>your risk of allergies? Lock It lists some of the theories.

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<v Speaker 1>Lower sunlight exposure during autumn and winter might reduce vitamin

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<v Speaker 1>D levels, which have a known connection to allergy risk.

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<v Speaker 1>Seasonal fluctuations in the levels of certain allergies such as

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<v Speaker 1>pollen or house dust mites, or the age at which

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<v Speaker 1>baby gets their first rhinovirus hay fever infection more common

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<v Speaker 1>in winter, may also contribute to allergic disease risk. Also,

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<v Speaker 1>the seasonal availability of different fruits and vegetables eaten by

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<v Speaker 1>the pregnant mother could alter the nutrition that baby is

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<v Speaker 1>born in different seasons received during important stages of early development.

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<v Speaker 1>But of course our bodies are complicated and more research

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<v Speaker 1>is needed before we can know for sure. Today's episode

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<v Speaker 1>is based on the article marked at birth Your birth month,

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<v Speaker 1>allergies and DNA are linked on how stuff works dot com,

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<v Speaker 1>written by Nicole bays Moore. Brain Stuff is production of

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<v Speaker 1>by Heart Radio in partnership at house stuff work dot

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<v Speaker 1>com and it is produced by Tyler Klang. Four more

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