Transcript LAST TIME

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Today
Vitamins, minerals, & deficiency diseases
Synergies between nutrition & disease
Especially vulnerable populations
4 faces of hunger
© T. M. Whitmore
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Contemporary acute deficiency
diseases: Iron
Iron deficiency:
Most common single nutrient deficiency in
the world
 > 1/3 of pop in many developing countries
Reduces cognitive performance, energy and
work ability, and resistance to infection
(especially to diarrheal and respiratory
diseases) even in mild cases
Severe forms = anemia
© T. M. Whitmore
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Contemporary acute deficiency
diseases: Iodine
Iodine deficiency:
Iodine is lacking in soils from some mountain
areas and in domr highly leached soils
 e,.g., Andes, Himalayas, C Africa, SE
Asia...
Major consequences:
 Swelling of thyroid (goiter)
 Important mental deficiencies (cretinism)
in kids if deficient in pregnant women
© T. M. Whitmore
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Contemporary acute deficiency
diseases: Vitamin A
Vitamin A deficiency:
Major consequences
 To vision can lead to blindness
 Also decreased immune function
 Kids with severe protein-calorie
malnutrition often have impaired sight as
a result of this
© T. M. Whitmore
Synergy: nutrition and disease
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Poor nutrition (protein-calorie or other
nutrient shortages) => reduced ability to fend
off new infections or makes existing ones
more severe
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Diseases interfere with nutrient absorption
and/or actively deplete nutrients from our
bodies
© T. M. Whitmore
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How poor nutrition => disease
Reduction in the body's innate immunities
(that react to general patterns of proteins in
pathogens)
Less effective phagocytosis (process by
which microorganisms are engulfed and
encapsulated)
Weakened epithelial barriers (protective
coverings on body surfaces inside and out)
Lowered lysozyme production (a bodily
protein that functions as an antibacterial)
© T. M. Whitmore
How poor nutrition => disease II
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Reduction in ability to generate acquired
immunities - the specific immunities one
acquires to a particular disease pathogen
Reduced production of humoral antibodies
Impaired cell-mediated immunity
© T. M. Whitmore
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How disease => poor nutrition
Most infections interfere with the body's
ability to absorb nutrition and/or actively
deplete nutrients
Reduced appetite
Poorer quality of diet ingested
Diseases deplete bodily tissue
Fevers => increased metabolic rate thus,
the body needs more kcal but they may not
be there
© T. M. Whitmore
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Special case of GI tract diseases
1.8 billion cases/yr of infant/weanling GI
diseases
Predominantly diarrheas, but also intestinal
parasites, cholera, & various types of
dysentery
 Impede absorption of nutrients (diarrheas
just don't let food sit in gut long enough)
© T. M. Whitmore
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Special case of GI tract diseases II
Many if not most deaths (perhaps 1 million/ yr
in the world) can be averted with adequate
treatment (called Oral Rehydration Therapy)
According to The Lancet (1978), ORT is
"potentially the most important medical
discovery of the 20th century"
Clean water with 60 cent packets of
salts/sugars to recover health
Full recovery => increased nutrition above
basic levels – often hard to get
© T. M. Whitmore
Oral Rehydration Therapy
(packet for addition to water)
Oral Rehydration Therapy
(home made)
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Especially vulnerable populations I
Increased likelihood of malnutrition and more
serious consequences
Women in general due to cultural traditions
that privilege food to males
Pregnant women
Poor nutrition => low birth weight babies
Developmental problems for baby physically
and mentally
Reduced resistance to diseases
Less able to breast feed (=> less resistance
for the baby as well)
© T. M. Whitmore
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Especially vulnerable populations II
Lactating women
Poor nutrition seldom greatly interferes
with ability to produce milk
But, poor nutrition does deplete the
mother's body of necessary nutrients
If nutrition is not better between end of
lactation and next pregnancy => spiral down
to chronic anemia etc.
Elderly
Ability to fend off infections is reduced
with great age and malnutrition hurts that
as well
© T. M. Whitmore
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Especially vulnerable populations III
Children
Malnutrition in infants and children very
problematic if timing coincides with critical
growth processes
 Up to age 5 risk is greatest
Especially at weaning age (approx 2 yrs)
Due to impure water used to make weaning
foods (not sufficiently boiled due to lack of
fuel) and general low hygiene =>
 Kids die from diarrheal diseases and
dehydration and malnutrition
Weaning foods are typically not nutrient© T. M. Whitmore
rich enough (e.g., maize gruels)
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Four Faces of Hunger I
I. Starvation/Famine
Widespread to complete lack of
protein/calorie nutrition
A small percentage of global hunger –
perhaps 1% at risk annually
Leads to increased mortality (usually to
infectious diseases not starvation per se)
Great social disruption => increased
problems with diseases and access to food
In any famine not all starve – the well off
can buy food -- thus NOT usually only a
simple shortage
© T. M. Whitmore
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Four Faces of Hunger II
II. Malnutrition/Undernutrition
Seasonal or periodic P/C under-nutrition
Most serious effects on kids and special
needs adults (pregnant and lactating women,
the elderly)
 measures of malnutrition in children
 Stunting - stature too short for age/sex
(adjusted for local norms) => chronic
 Wasting – weight too light for age/sex
(adjusted for local norms) => acute
© T. M. Whitmore
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Four Faces of Hunger III
III. Micro-nutrient deficiencies
 Vitamin and mineral shortages
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Sometimes called “hidden hunger”
IV. Nutrition-depleting illnesses
Secondary malnutrition
Most common nutrient depleting diseases
are infant/weanling diarrheas – 5 million
deaths annually world wide
© T. M. Whitmore
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Global Hunger
Global situation late 1990s
Data drawn from FAO’s SOFA report 2007
http://www.fao.org/docrep/010/a1200e/a1200e
00.htm
The International Food Policy Research
Institute:
http://www.ifpri.org/media/20071012GHI.asp
The concept of “food security”
© T. M. Whitmore
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Global Trajectories of Hunger I
Proportions undernourished (or food insecure)
Late 1970s ~ 28%
Late 1990s ~17%
Thus, some real progress
Less progress in absolute numbers
Micro-nutrient deficiencies
Iron: 40% of global south
Iodine: 12% of global south
Vitamin A: 14% of kids in global south
© T. M. Whitmore
Global Trajectories of Hunger II
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Absolute numbers undernourished (or food
insecure)
1970s ~ 900m; 2000 ~ > 800 m
=> decrease of ~ 100m in absolute numbers
(but smaller %)
Children 1993 ~ 200 m; now ~ 175 m
World food summit target (MDG) in 2015 =>
400m
Current trajectory => 475-500m by 2015
Progress in some places, regression in others
© T. M. Whitmore
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Regional differences malnourished
or food insecure
Global South
Sub-Saharan Africa
E. Asia, SE Asia, & Pacific
South Asia
Latin America & Caribbean
Near East & N. Africa
Developed Economies (mostly N America)
© T. M. Whitmore
Source: FAO
Source: FAO
Source: FAO SOFA 2007
Number of malnourished children, 1993, 2010, and 2020
Source: IFPRI IMPACT simulations.
Source: IFPRI Global Hunger Index 2007
Source: FAO SOFA 2007
Countries with food shortfalls – requiring assistance