There is nothing new in the fact that a person's nutrition can substantially affect mood, behavior, and brain function. The human brain is quite demanding when it comes to energy consumption. Our food intake influences brain chemistry and neural function (affecting neurotransmitters that transmit nerve impulses from one neuron to another), thereby influencing mood, sleeping patterns and etc. Deficiencies or excesses of certain vitamins or minerals may
impair brain function.
The nutritional factors that can influence mental health, include: overall energy consumption, intake of basic nutrients such as proteins, carbohydrates, fats, alcohol, vitamins and minerals. usually, the lack of several nutrients rather than a single nutrient are the cause of deterioration in brain functioning.
Within the western world, alcohol is #1 wanted in the list of nutritional deficiencies that affect neural function. Certain illnesses are also responsible for nutritional deficiencies (since they limit absorption of nutrients into the bloodstream or increasing nutritional requirements.
Energy, represented by the caloric value of a certain
food, is derived from the carbohydrate, protein, fat,
and alcohol found in our daily nutrition. Vitamins
and minerals are also essential to the body, although they
don't provide energy.
The human brain uses about 20 to 30% of a person's energy
intake. Relative to it's size and weight, it is very
demanding. That's why People who don't consume enough
calories in their diet are more likely to experience changes
in their brain functioning. Even the mere decision to skip
breakfast has its consequences: it is associated with lower
verbal fluency, lower ability to solve problems and the lack
High levels of energy deprivation (continual hunger,
starvation) massively affects mental responsiveness.
The body responds to energy deprivation by slowing down
most non-essential functions, hormonal levels, oxygen
transportation, immune level efficiency, and several other
physical functions that somewhat affect brain function.
People with a continual low energy intake often feel
apathetic, sad and depressed.
Fetuses and infants are especially sensitive to brain
damage caused by malnutrition. Extent of damage depends
malnutrition's time span along with the stage of
development. Malnutrition in childhood has been
associated with low intelligence and cognitive defects.
The Voyage Into the Brain
Your brain works just like a vehicle. A vehicle
requires gas, oil, water, brake fluid and other components
to function well. Your brain also requires certain materials
to function well: Sugar (glucose), Vitamins &
Minerals and other essential chemicals. Our main mental
fuel is Glucose that can be found in carbohydrates of all sorts.
Aside of it's main fuel, our brain is producing essential
proteins and fatty acids to grow and maintain connections
between the neurons and to add myelin (the fatty sheath) to
axons. Without the correct quantity of particular building
blocks, your brain won't function properly. Deficiency or
overabundance of an essential nutrient can greatly effect
our nervous system.
Vitamins & Minerals are essential to the body but
are not manufactured by the body. Hence, these materials
must be consumed within our daily diet.
Lipids (fats)- some fats are essential for proper
brain function. Two lipids especially critical to the brain
are the n-6 and n-3 fatty acids. Low levels of n-3 cause
visual problems by badly affecting the retina. Studies in
rats have shown that diets without n-3 fatty acids cause
learning and motor disabilities and may damage systems that
use the neurotransmitters dopamine and serotonin in the
frontal cortex. The n-6 fatty acids affect neurotransmitter
release and contribute to the ability of neurons to use
glucose for energy.
On their way to the brain, the nutrients face
tricky pathway and overcome several obstacles:
First, the stomach acid breaks some of them down.
Next, they are absorbed through the cells lining
the intestine and go through blood vessel barriers
into the bloodstream. Next, nutrients need to avoid
being destroyed by the liver's metabolism processes.
Once in the bloodstream, nutrients need to penetrate
the blood-brain barrier.
The Blood Brain Barrier
The blood-brain barrier keeps many substances out
of the brain, allowing some nutrients into the brain. Any
substance must cross through these tiny blood vessels in
order the reach the neurons. The Blood Brain barrier (BBB)
can be crossed in 3 different ways:
A. Some materials can fit through "holes" in the BBB.
B. Substances can be "carried" through the BBB.
C. Some materials can break down the BBB.
Malnutrition and the Brain
Vitamin and mineral deficiencies can be caused
due to these factors:
2. Poor diet
3. Poor absorption of vitamins and minerals
4. Damage to the digestive system
Since the brain of a human fetus grows rapidly from
the 10th to 18th week (of pregnancy), it is crucial
for the mother to eat well during this time. The brain
grows most rapidly just 2 years after birth. Malnutrition
during these periods of rapid brain growth may potentially
cause severe damage to the nervous system, affecting neuron
and glial cell development. Damage to the glial cells may
change myelin development that continues to form around
the axons for several years after birth.
Children who do not receive adequate nutrition in their
first few years of life may develop problems later. Often
the effects of malnutrition and environmental problems,
such as emotional and physical abuse, can combine to create
behavioral problems. Hence, the exact causes of behavioral
disorders are difficult to determine.
Some effects of malnutrition can be repaired by a
proper diet, so not all of the effects of poor diets
are permanent. Researchers believe that the timing of
malnutrition is an important predictor in determining
whether problems will develop. This means that the absence
of a particular nutrient while required by a specific part
of a growing brain may cause a specific damage there.
The study of the Connection between Nutrition, Brain and
Behavior is relatively new. Scientists have just begun to
understand how changes in particular nutrients alter the
brain and how these neural changes then affect intelligence,
mood, and action. Experiments investigating the interactions
between nutrition and behavior are complicated due to several reasons and factors:
1. There is a link between poor nutrition and environmental
factors. Therefore, changes in behavior may not be due to
poor nutrition only. Factors such as education, social and
family problems may affect behavior too.
2. It is difficult to determine if a particular vitamin
or mineral has a certain effect on behavior. Ethics dictate
that experiments forbidding a person from eating a certain
nutrient cannot are illegal, so much of the data comes from
animal experiments. Studies in humans are generally limited
to examining the effects of famine and starvation, cases
where most of the essential nutrients are missing.
3. People respond differently to different diets. In other words, there is a large individual variation in the body's response and need for different nutrients.
4. A change in diet may have a placebo effect.
If a person thinks a change in diet will affect behavior,
it may actually affect behavior even if the nutrients are
not the cause of the change. Therefore, experiments must
be conducted using a placebo control double-blind manner.
(neither the experimental subject nor the experimenter know
who has received a modified diet.