Standard American Diet Negatively Impacts Learning and Memory
Dr. Kathie F. Nunley (c)2014
increased their daily consumption of calories by more than 25% over
the past 50 years. We are now beginning to see the deleterious effect
this diet change is having on our brains, particularly in how it impacts
learning and memory.
consumption and its associated weight gain has been linked to many
health related problems such as high blood pressure, insulin levels
and measures of inflammation. But we are now seeing a wide range of
research projects linking these high insulin levels and inflammation
to cognitive problems, both in young children trying to learn and
aging adults and the rise in Alzheimer's.
The biggest area
of concern for educators is the effect these diets have on the hippocampus
- the brain region in charge of memory formation - the cornerstone
to learning. The vast majority of the increased calories consumed
is coming from saturated fats and refined carbohydrates. Diets high
in fats and refined sugars cause significant impairment to the hippocampus.
These diets slow neurogenesis, the hippocampus' ability to regrow
and replenish new neurons; they also have a negative effect on synaptic
plasticity and they lead to a decrease in chemicals responsible for
associated with our American diet is how it undermines emotional-enhanced
learning. Normally, a moderate amount of stress or emotional excitement
leads to an increase in learning and retention. But diets high in
sugar and high fructose corn syrup, cause a decrease in stress-induced
corticosterone release. That means, they negate the effect. So while
we would expect highly motivated, excited children, under a moderate
amount of stress, to learn faster and perform better on tests, we
may have lost that advantage due to our high
much of this research has been done using rats in a laboratory, we
are also seeing new reserach using humans in the real world. And this
research also points to the problems associated with high sugar diets
that are also low in Omega-3 fatty acids (another hallmark of the
Standard American Diet).
piece of research, out of UCLA, showed that students with high
sugar intake and the common high Omega 6 / low Omega 3 diet, had lower
cognitive scores and insulin resistance. The good news in this reserach
is that Interestingly, once diets were supplemented with high Omega-3
foods, many of the the negative cognitive effects of the high sugar
diets were eliminated.
A separate research
project looked at the diets of children aged 7 - 9. They compared
groups of children who had diets high in saturated fatty acids (Omega-6)
with those whose diets were higher in Omega-3 fatty acids. Those children
high in Omega 6's had
much lower memory and learning scores than did children whose diets
include high Omega-3 fatty acids. The children who had high Omega-3
diets just had better hippocampal function.
So what are educators
and parents to do? Education in our schools should include information
on how children learn best and that includes nutrition. Schools need
to be an example of how to create healthier climates for learning.
These could include:
Fructose Corn Syrup and high Omega-6 oils from the cafeteria and vending.
(read labels, avoid vegetable oil, corn oil and "hydrogenated"
of Omega-3 rich foods: These include fish, flax, olive oil, coconut,
coconut oil, avacado, olives, palm oil, and fats from animals fed
in the difference between Healthy Fats and Unhealthy Fats.
food convenient. (Apples should always be presented sliced and ready
for dipping if we want them to compete with french fries!) Move healthier
options to the front and discount their price. Make unhealthy food
more expensive and harder to find.
caloric intake by providing higher protein options which eliminate
snacking and hunger throughout the day.
parents and students on the advantages of lower caloric diets, high
in Omega-3 fatty acids, low in Omega-6 foods and eliminating high
fructose corn syrup completely from the diet.
Agrawal R &
Gomez-Pinilla F (2012). "Metabolic syndrom in the brain: deficiency
in omega-3 fatty acid exacerbates dysfunctions in insulin receptor
signalling and cognition." Journal of Physiology 590, 2485–2499.
Baym, C. et
al (2014). "Dietary Lipids are differentially associated with
hippocampal-dependent relational memory in prepubescent children."
American Journal of Clinical Nutrition. Vol 99(5); 1026-1032.
M. & Doraiswarmy, M. 2009. "Does Eating Fewer Calories Improve
the Brain?". Scientific American. March.
& Zied, E. (2010). The standard American diet and its relationship
to the health status of Americans. Nutrition in Clinical Practice,
Ross, A.; Darling,
J; & Parent, M. (2013). "High Energy Diets Prevent the Enhancing
Effects of Emotional Arousal on Memory." Behavioral Neuroscience,
Vol 127(5), 771-779.
F. Nunley is an educational psychologist, author, researcher and speaker
living in southern New Hampshire. Developer of the Layered Curriculum®
method of instruction, Dr. Nunley has authored several books and articles
on teaching in mixed-ability classrooms and other problems facing
today's teachers. Full references and additional teaching and
parental tips are available at: http://Help4Teachers.com Email her:
Kathie (at) brains.org
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