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Today. Vitamins, minerals, & deficiency diseases Synergies between nutrition & disease Especially vulnerable populations 4 faces of hunger. Contemporary acute deficiency diseases: Iron. Iron deficiency : Most common single nutrient deficiency in the world
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Today • Vitamins, minerals, & deficiency diseases • Synergies between nutrition & disease • Especially vulnerable populations • 4 faces of hunger
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
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
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
Synergy: nutrition and disease • Poor nutrition (protein-calorie or other nutrient shortages) => reduced ability to fend off new infections or makes existing ones more severe • Diseases interfere with nutrient absorption and/or actively deplete nutrients from our bodies
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)
How poor nutrition => disease II • 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
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
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)
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
Oral Rehydration Therapy (packet for addition to water) Oral Rehydration Therapy (home made)
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)
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
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-rich enough (e.g., maize gruels)
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
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
Four Faces of Hunger III • III. Micro-nutrient deficiencies • Vitamin and mineral shortages • 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
Global Hunger • Global situation late 1990s • Data drawn from FAO’s SOFA report 2007 • http://www.fao.org/docrep/010/a1200e/a1200e00.htm • The International Food Policy Research Institute: • http://www.ifpri.org/media/20071012GHI.asp • The concept of “food security”
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
Global Trajectories of Hunger II • 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
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)
Number of malnourished children, 1993, 2010, and 2020 Source: IFPRI IMPACT simulations.