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| Feed your brain the right foods. |
A new study from the University of New
South Wales in Australia published in the journal Brain Behavior and Immunity, shows that just one week of eating an unhealthy diet is enough to
cause lasting memory impairment in rats.
For a week, the rats were given access
to a bottle of sugar water in addition to a healthy diet, or were fed a
cafeteria-like diet loaded with cakes, cookies, and fat. Although only the rats
on the cafeteria diet gained weight, both groups of rats had memory impairments
compared with control animals who ate only healthy foods, suggesting that
weight gain alone wasn’t to blame for their memory lapses.
Poor Diet Damages the Hippocampus
The rats had little trouble with
object recognition, a type of memory that involves a brain region called the
perirhinal cortex. But they did far worse with place recognition, a type of
memory that involves a brain region called the hippocampus, which is responsible
for many types of memory formation, including retaining new facts.
In the rats on the high-sugar or
cafeteria diet, the researchers found that the hippocampus had become inflamed,
impairing its function. The inflammation and memory damage lasted for at least
three weeks after the rats were returned to a healthy diet.
Although rats aren’t a perfect model
for humans, their hippocampus functions in very similar ways to ours. In
humans and rats, the hippocampus not only helps us learn but also helps us
navigate places and record events as they happen. Keeping it healthy is
invaluable for learning and recall.
“A healthy diet is critical for
optimum function,” said study author Professor Margaret Morris in an
interview with Healthline. “Our data suggests that even several days of bad
diet may impair some aspects of memory.”
The hippocampus is also used to
regulate the body’s stress system. If it’s not able to do its job properly,
stress can get out of control, dumping hormones into your bloodstream that will
circulate back to the hippocampus and damage your memory further.
To complete the vicious circle, when
stress levels are high, the body’s hunger systems shift. This causes you to
selectively crave fatty and sugary foods.
Memory and Age
Although a little junk food here and
there won’t have too much impact on a young person, a lifetime of poor eating
can add up. If your hippocampus doesn’t get a chance to recover from the
sugary, fatty onslaught, the inflammation could become long-term damage.
“Some studies show a decline in
cognition with aging, and it is possible that an unhealthy diet may be
particularly unhelpful in this group,” said Morris. Older brains take longer to
recover from insults such as hangovers, so they might also be more vulnerable
to damage from a junk food diet.
As seniors living on their own lose
mobility, some are more likely to eat pre-packaged foods, such as frozen
dinners, which tend to be high in fat, sugar, and salt. So this finding might
also help explain the role that diet plays in the development of memory
impairment in diseases like Alzheimer’s.
