Speaker 1: Welcome to brain Stuff production of I Heart Radio. Hi
Speaker 1: brain Stuff Lauren boge obam here with a classic brain
Speaker 1: Stuff episode. As we often discuss on this show, human
Speaker 1: bodies are gloriously weird things that science still doesn't entirely understand.
Speaker 1: For example, allergies. They're an immune system response that's influenced
Speaker 1: by everything from our genes to what we're exposed to
Speaker 1: during our first months of life. Today's episode deals with
Speaker 1: how even the season it was when you were born
Speaker 1: can make a difference. Hey, brain Stuff, Lauren bog obam here,
Speaker 1: people born in the fall and winter are more likely
Speaker 1: to have allergies than people born in the spring and summer.
Speaker 1: While that might be news to you, it certainly was
Speaker 1: to me. The scientific community has known about it for years,
Speaker 1: and a recent study published in the European Journal of
Speaker 1: Allergy and Clinical Immunology set out to discover why it happens.
Speaker 1: Many of us have a unique physical identify or maybe
Speaker 1: a noticeable birth mark. We also have certain markers on
Speaker 1: our DNA that can help determine things like our weight
Speaker 1: and height, our mood swings, and even our risk for
Speaker 1: some conditions like schizophrenia. The researchers found out that those markers,
Speaker 1: called epigenetic marks, can help determine whether we're at risk
Speaker 1: for allergies. We spoke with Dr Gabrielle Lockett, lead author
Speaker 1: of the study, via email. She said epigenetic marks are
Speaker 1: a way to regulate the expression of genes without altering
Speaker 1: the underlying DNA sequence. A gene expression is a process
Speaker 1: where information stored in our DNA is translated into instructions
Speaker 1: for making proteins or other molecules. Lockett, who is a
Speaker 1: postdoctoral research fellow in the Faculty of Medicine at England's
Speaker 1: University of Southampton, says that researchers have long known that
Speaker 1: your birth season, as well as certain environmental exposures like smoking, famine,
Speaker 1: or even your social environment, are associated with certain epigenetic
Speaker 1: marks and can alter gene expression. They just didn't know why.
Speaker 1: She said epigenetic marks were a good candidate for the
Speaker 1: connecting mechanism between birth season and allergies because they can
Speaker 1: be altered by environmental exposures, can influence gene expression, and
Speaker 1: can last many years. Lockett and her team scanned DNA
Speaker 1: samples from three hundred and sixty seven eighteen year olds
Speaker 1: who were born on the Isle of Wight in England.
Speaker 1: They paid particular attention to certain markers called DNA methylation
Speaker 1: in the samples. DNA methylation is one type of epigenetic mark.
Speaker 1: Methyl groups help cells reproduce normally, and they can literally
Speaker 1: turn genes on or off. When your methyl groups are depleted,
Speaker 1: bad genes like those that cause cancer are turned on.
Speaker 1: Researchers wanted to know whether certain markers could be linked
Speaker 1: to the time of year a person was born, and
Speaker 1: whether those people experience allergies like xzema or asthma. Lockett said,
Speaker 1: we found that yes, DNA methylation at certain places in
Speaker 1: the genome is consistently associated with season of birth. We
Speaker 1: went on to discover that these birth seasonal epigenetic marks
Speaker 1: are associated with gene expression and could potentially provide a
Speaker 1: link to allergic disease. Luckett says her team found similar
Speaker 1: results when they duplicated the study with a group of
Speaker 1: eight year olds from Holland, but the markers were not
Speaker 1: present when the team tested a group of newborns. Lackett
Speaker 1: says this suggests that epigenetic markers arise after birth or
Speaker 1: maybe even as a result of one's environment. The link
Speaker 1: between birth month, and allergy risk applies to all kinds
Speaker 1: of allergies, Luckett said. For decades, studies have shown that
Speaker 1: people born in autumn and winter are at an increased
Speaker 1: risk of not only rhinitis hay fever, but also food allergy,
Speaker 1: asthma and eczema. She continued, One large Dutch study found
Speaker 1: that people born in ottuman winter were at increased risk
Speaker 1: of having immune responses to non seasonal allergies such as
Speaker 1: egg white and cow's milk, as well as two seasonal
Speaker 1: allergies like pollen, cat dog and house dust mighte. This
Speaker 1: suggests that season of birth is associated with a person's
Speaker 1: risk of allergy in general. The effect is not restricted
Speaker 1: to seasonal allergies. So why would your birth month affect
Speaker 1: your risk of allergies? Lock It lists some of the theories.
Speaker 1: Lower sunlight exposure during autumn and winter might reduce vitamin
Speaker 1: D levels, which have a known connection to allergy risk.
Speaker 1: Seasonal fluctuations in the levels of certain allergies such as
Speaker 1: pollen or house dust mites, or the age at which
Speaker 1: baby gets their first rhinovirus hay fever infection more common
Speaker 1: in winter, may also contribute to allergic disease risk. Also,
Speaker 1: the seasonal availability of different fruits and vegetables eaten by
Speaker 1: the pregnant mother could alter the nutrition that baby is
Speaker 1: born in different seasons received during important stages of early development.
Speaker 1: But of course our bodies are complicated and more research
Speaker 1: is needed before we can know for sure. Today's episode
Speaker 1: is based on the article marked at birth Your birth month,
Speaker 1: allergies and DNA are linked on how stuff works dot com,
Speaker 1: written by Nicole bays Moore. Brain Stuff is production of
Speaker 1: by Heart Radio in partnership at house stuff work dot
Speaker 1: com and it is produced by Tyler Klang. Four more
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