Scientists believe the mood of teenagers could be determined by
the food they eat - and are about to put their theory to the
test.
A group of Australian scientists believe too few omega-3 fatty
acids, found in fish and seafood, and too many omega-6 fatty acids,
found in processed oils and nuts, raises the risk of depression in
adolescents.
Up to 1000 Sydneysiders aged 14 to 17 will be recruited for the
biggest study of its kind on whether adolescents truly are what
they eat.
Lower seafood consumption has been linked to higher rates of
depression in adults. The study will attempt to prove it affects
teenagers in the same way.
The How Food Affects Mood study, by the Australasian Research
Institute at Sydney Adventist Hospital and the University of NSW,
will use DNA testing from cheek swabs and dietary surveys.
Researchers want to know if an imbalance in levels of omega-3
and omega-6 - due to increases in processed foods - heightens the
probability of depression.
Humans evolved with a diet equal in both essential fatty acids
but current Western diets have up to 15 times more omega-6 than
omega-3.
Omega-3 fatty acids are critical to brain development and
function, but because our bodies cannot effectively make them we
rely on dietary sources.
However, most Australians consume less than a quarter of the
optimal recommended intake because it is only found in a few foods,
including oily fish such as salmon and sardines.
Previous NSW research showed children need to eat five times
more fish and seafood than they do.
The study will be the first to measure which variant a teenager
has of the serotonin transporter gene, which is responsible for our
uptake of "feel-good" serotonin and mood control.
In 2006 Australian research found people who carry a "short"
version of the gene tend to be more susceptible to depression,
while those with the "long" version are more resilient against
negative life events. The institute's Dr Ross Grant said the
results would be used to give teenagers positive messages about
healthy eating. "Often kids who are physically unhealthy are
emotionally unhealthy as well," he said.
Co-researcher Margaret Morris said dietary intervention could
ultimately be used to prevent and treat mood disorders.
"If there is a causal link between omega-3, serotonin
transporter genotype and depression, we can develop better
strategies to deal with it," she said.
Beaumont Hills parents Tracy and Martin McCoy say it's a
challenge to get their three daughters to eat enough seafood. While
Courtney, 13, doesn't mind prawns, Emilly, 16, and Amy, 9, won't go
near fish.
"I don't like the fishy taste, and it stinks," Emilly said.
Amy added: "I'll have the chips."
American research suggests fish oil capsules and fatty fish do
an equally good job of enriching the blood and other body tissues
with omega-3 fatty acids.
Researcher Dr Williams Harris, of the University of South
Dakota,said: "We went into the project assuming that fish would be
better, based on some previous literature [but] it doesn't make any
difference whether you get your omega-3 fatty acids from a
concentrate in a capsule or in fish - they have the same effect on
enriching the tissues with omega-3."
Nevertheless, Dr Harris said he would encourage people to eat
fish.
"Fish of course brings with it proteins and minerals and other
factors that are good for our health that the capsules don't bring,
but we weren't able to measure any of those things," he said.
Fatty Acid Facts
* Omega-3s: cannot be made by the body. They are obtained from
oily fish, cod liver oil and egg. Emerging evidence shows links
between low levels of omega-3 and mood, behaviour, learning and
neurological disorders.
* Omega-6s: come from industrial oils used in takeaways, ready
meals, chips, biscuits and ice-cream.
* Western diets have up to 15 times more omega-6 than
omega-3.
(Agencies via China Daily January 7, 2008)