45
may/june 2015
yogajournal.com.au
The molecules in food also affect our genes through
epigenetics. For instance, research suggests that flavonoid
antioxidants in things like dark chocolate and certain
vegetables, or zinc from oysters or omega-3 fats actually change
the way our genes behave, says Dr Ramsey. So if you have
a genetic predisposition to depression, your diet can either
increase or decrease your risk of developing the illness.
Bacteria in the gut play a variety of roles for keeping the
brain healthy. “We have a very beautiful, wonderful ecosystem
of organisms that live in the mucosal areas of the body like the
lining of our stomach and intestines,” says Dr Selhub, who
studies the link between gut bacteria and mental health. One way
these bacteria benefit the brain is by helping to keep intact the
gut lining, which is full of nerve cells that constantly send
messages to the brain. The gut lining also acts as a barrier to
toxins and aids digestion so your brain is protected from bad stuff
while still getting needed nutrients. But overwhelm the gut lining
with the wrong foods – processed sugars, some cured meats (like
deli meats), trans fats and processed, white-flour carbohydrates
- and it can become inflamed and start to break down, says Dr
Selhub, adding, “And we know that more inflammation is
associated with more mood disorders, including depression.”
Another way gut bacteria seem to aid the brain is by
synthesising many neurotransmitters, such as serotonin and
dopamine. A 2011 study at McMaster University in Canada
found that changing the balance of gut bacteria in mice not
only changed the levels of these chemicals in their brains,
but also caused obvious changes in behaviour, making usually
timid mice act more boldly and adventurously – suggesting
a shift in anxiety levels.
Although Dr Jacka notes that researchers don’t yet
understand how gut bacteria affect neurochemicals in the
human brain, what is clear is that diet is one of the keys to
promoting healthy gut flora. Refined carbohydrates, sugar and
saturated fats upset the balance of bacteria. On the other hand,
“prebiotic foods,” such as asparagus, Jerusalem artichokes,
bananas, oatmeal, unrefined wheat, chicory root and legumes,
support gut bacteria and their functions.
The effects of food on our brain may be speedier than you’d
expect – days, not years. Andria Gutierrez says she noticed
a mental-health upswing after two weeks of following a
healthier diet. “My mind just started to feel less
cluttered. I started to wake up feeling rested and
with a smile,” she says. “I can remember that
first day I woke up feeling good – it still gives
me the chills because it felt like a miracle,
a true blessing.”
Good-mood food
The field of nutritional psychiatry is still in its
infancy, but research to date suggests that what
seems to matter the most is overall diet quality.
Here are five ways to improve the caliber of yours:
get back to basics Diets that focus more on whole,
unprocessed foods – regardless of whether they include
or exclude certain grains, meats or dairy products –
tend to correspond to better mental health than typical
“Western” diets full of fast and processed food, cured
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