WHAT IS PUBLIC HEALTH NUTRITION? • Problems related to inadequate quantity and quality of the habitual diet • Problems related to excessive intake of ...
Author: Joel Harper
6 downloads 0 Views 234KB Size
WHAT IS PUBLIC HEALTH NUTRITION? • Problems related to inadequate quantity and quality of the habitual diet • Problems related to excessive intake of quantity of the habitual diet • Food-related problems that affect the health and function of a large percent of the general population or specific ages, gender, geographic, socio-cultural groups or developmental/physiologic stages • Problems prevented or ameliorated by identification of risk factors and early detection by screening when feasible, in contrast to only specific nutrient treatment


quantity of food for requirements

• Low density of specific nutrients • Poor absorption of a given nutrient or nutrients - presence of other constituents of the food such as high fiber and phytate - competition of nutrients (i.e., iron with zinc) • Infection and intestinal parasites • Malabsorption due to enzyme deficiencies, structural damage to intestinal surfaces • Drug-nutrient interactions

EXCESSIVE INTAKE OF FOOD AND NUTRIENTS • Food intake above physiological needs for normal function and growth in children • Intake of vitamins, minerals and other micronutrients far in excess of nutritional needs EXAMPLES: ™ Fast food addiction and calorie-dense snacks ™ Megadoses of vitamins and other micronutrients and “natural supplements”


Will focus on interconnected area of the world global outlook -- the Nutrition Transition Developing countries with predominately poor people plus an increasingly wealthy, middle-class, urbanized population with adaption of physical activity, stress, etc.), over-nutrition with high-energy diets, alcohol, high intake of refined sugars, etc. AND Industrialized, wealthy countries with growing disadvantaged populations with growing food security, income and hunger and malnutrition

MISCELLANEOUS FACTORS IN THE ETIOLOGY OF UNDERNUTRITON Geographico-climate Unproductive soil Climate (high temperature, extremes of rainfall) Educational Too few schools (illiteracy) Social Illegitimacy; family instability Absence of family planning (children too cIosely spaced; population pressure) Poor communications (food distribution) Alcoholism Economic National poverty (low gross national product) Family poverty (low per capita income) Low level of industrialization Agronomic Old-fashioned methods of agriculture Inadequate protein production (animal and vegstable) Concentration on inedible cash crops Poor food storage. preservation arid marketing Medical High prevalence of conditioning infections measles, diarrhea, tuberculosis, whooping cough. Malaria, intestinal parasites) Sanitation Unclean, inadequate water supply Defective disposal of excrete and rubbish Cultural Faulty feeding habits of young children Recent urbanization (changing habits) Limited culinary facilities Inequitable intra-familial food distribution Overwork by women (limited time for food preparation for children) Sudden weaning (psychological trauma)

INTRODUCTION Political-cultural

Community nutrition level*


Socioeconomic Food factors considerations (economic, education)

Community nutrition level (CNL) ‘equation’ *Especially vulnerable groups

Aspects of health (contributory infections, environmental hygiene, healthrelated services)

PRINCIPAL PROBLEMS IN THE SO-CALLED DEVELOPING COUNTRIES OR THE “EMERGING NATIONS” (and to a lesser degree, in the industrialized nations) The principal public health nutrition problems Maternal malnutrition with: • Poor nutrition in preconception period • Maternal depletion, poor pregnancy weight gain, and depletion of meager nutrient stores (fat and muscle mass, iron, calcium, zinc, etc.) • Maternal anemia, small pelvic outlet from earlier rickets, or protein energy malnutrition • Eat down to have small baby for easier delivery • Low birth weight, small for dates (i.e., low BW term newborns (high mortality, CNS damage, poor resistance to infection, risk for adult CV and diabetes (Barker’s Hypotheses)) • Breast milk may be deficient in vitamins (B12 ,folate, and A ,for example) and quantity if severely malnourished

MATERNAL DEPLETION Leads to poor nutrition status, decreased longevity Aftermath of: • Continuous period of closely spaced pregnancies interspersed • Near continuous lactation • Child-bearing starting in adolescence or young adulthood • Hard physical work • Poor diet quality and quantity (eating down, cultural prohibitions) • Condition in pre-conception or entry to pregnancy/lactation with poor body nutritional stores Nutrients: Macronutrients — poor fat stores and lean body mass Micronutrients — poor stores of iron, calcium, zinc, vitamin A & B12, folate, iodine, thiamine

INFANT FEEDING Exclusive breast feeding (EBF) for first six months (those not EBF have double the infant mortality rate as bottle-fed infants in developing countries) Breast milk is sterile, multiple anti-infective mechanisms, nutrients tailored to needs and developmental stage of infant, promotes brain development, growth-stimulating factors of digestive tract, psychological benefits for maternal infant pair, few safe alternatives, enhances child spacing (called “lactational ammenorrheä (suppresses ovulation —but imperfectly))

WEANING CHALLENGE – FEEDING THE TODDLER NEED TO ADD SOLID FOODS TO SUPPLY MORE CALORIES , PROTEIN, IRON, AND OTHER MICRONUTRIENTS (CHILD OUTGROWING THE MILK SUPPLY) Continue breast feeding until 2+ years child; growing rapidly Need for energy-dense food (small stomachs!) with high-quality protein, energy, vitamins, minerals, trace elements (iron, zinc, iodine, calcium, vitamins A,C ,B,D, esp. B12) Above supplied by local beans, cereals, dairy products, and need for modest amounts of animal foods; i.e., meat, fish For micronutrients, green and orange plant foods and fruits for vitamins C and A NOTE: Death rates around weaning time 30-50-fold higher in developing countries than in rich nations, due to combination of malnutrition and infection

SCHOOL-AGE-TO-ADULT PROBLEMS Chronic energy insufficiency Late onset of puberty Stunting as adults Nutritional anemias complicated by other anemias Iodine deficiency in some areas Other micron nutrient deficiencies Calcium deficiency, with osteoporosis in older people (calcium depletion) and osteomalacia (adult rickets) Fluorosis in some areas Ben Ben (thiamine deficiency) Functional outcomes: poor school performance and attention; decreased physical activity; decreased work capacity; decreased cognitive function; overall diminishment of social and economic development

MAIN DEFICIENCY SYNDROMES AND CONDITIONS PROTEIN-ENERGY MALNUTRITION, from mild to severe Severe states: Kwashiorkor (protein deficiency) Marasmus (total energy depletion) Both are seen in young children (toddlers) and adults Often seen in combination KWASHIORKOR, meaning “displaced child”, occurs right after weaning or precipitated by infection (often measles, HIV, pneumonia, etc.) •Child edematous with low serum albumen •Decreased immune function - high infection complications •Child lethargic, apathetic, electrolyte and hormonal imbalances •High case fatality •Treatment is high protein diet and treat infection if present. •Takes two weeks and full recovery

MARASMUS •Total starvation “skin and bones appearance” •The child is ravenous •Often ravenous and very irritable and hungry •Also infection risk •Chronic serious infections such as Tbc; HIV can contribute to marasmus •Early weaning under six months, with poor substitute causes marasmus •Recovery takes two months + •Treatment is high-energy-dense complete diet •Cognitive impairment if early in life Stunting: Prevalence 40-60% of children Poor lifelong history of energy, undernutrition, plus zinc deficiency and, at times, iodine deficiency Functional outcomes: Early onset - deceased cognitive function; decreased physical work capacity and productivity Used as an economic indicator

LEADING MICRONUTRIENT DEFICIENCIES (HIDDEN MALNUTRITION IN MILD FORMS) • Widespread globally • Functional disabilities • High societal/economic cost if not prevented and treated Approaches to control: • Nutrition education • Food-based as for iron, zinc. vitamins A and B12, calcium need for improved household agriculture • Food fortification where feasible, and people in market economy, or treated water for iodine deficiency • Pill or capsule distribution (single MN or multiple MNs) (can be problematic) • Appropriate food technologies: germination, fermentation, soaking, malting, and solar drying of seasonal fruits and vegetables and meat/fish


Global problem —once very prevalent in USA industrial cities Present in refugees in large crowded cities in UK and USA Seen in Africa despite sun - low calcium diet once weaned At-risk groups are vegetarian, wearing occlusive clothing, not in sunlight (Moslem women in particular and their infants)

Problems: • Skeletal deformities of all pressure-bearing long bones • Chest deformities-interferes with chest and lung expansion, with increased pneumonia, poor bony calcification, and permanent deformities — bowing, short. In women, this is a serious hazard in pregnancy/delivery, as the pelvis is misshapen with small birth outlet • Adults —poor physical work performance if skeletal deformities severe Approach: Vitamin D, calcium, exposure to sunlight

SPECIFIC MICRONUTRIENT DEFICIENCY DISEASES Iodine deficiency disease: •Geographic distribution — far from the ocean, in mountains where water is from melted snow and ice, river deltas, no ocean products • Pregnancy: increased wastage, severely retard affected child born (cretin), with irreversible mental and physical retardation • Goiter common • In lesser forms and older children and adults, mentally dull, short, poor ability to work and earn • Huge waste of human resources - where treated economic development follows Approaches to elimination: • Government legislation to iodize all salt • Hard-to-reach populations, iodine drops in drinking water or in irrigation water • Iodine in oil by mouth or by injection every 1-3 yrs. Vitamin A deficiency: Lack of intake of vitamin A-containing fruits and vegetables, milk, and organ meats Blindness leading global result

World map to show areas of recent or continuing iodine deficiency. Many other countries, particularly in Africa and the Middle East, probably have iodine deficiency but have not yet been surveyed

VITAMIN A DEFICIENCY • Long known to be associated with blindness and signs of “toad skin” (ophthalmologist Sommers noted that in populations with eye signs of VAD, the children had very high levels of mortality and morbidity) • Eye signs were dryness, clouding, then rapid corneal clouding, and liquifaction and extrusion of lens • Increased deaths from infection; especially pneumonia, diarrhea, measles • Noted in VAD: body barriers to infection damaged (i.e., skin, all mucous membranes, eye covering); immune function impaired Approaches: • Nutrition education, cultivation of vitamin A-rich fruits and vegetables (sweet potato, carrots, tomatoes, green leafy vegetables) • Food fortification • Pharmaceuticals: high-dose vitamin A capsule distribution to children under five years of age and nursing mothers every six months, low doses to pregnant women

IRON DEFICIENCY Most prevalent deficiency globally, next to energy (calories) Many functional impairments: • Cognitive function, activity and attention - may not be completely reversible if severe and early in life • Poor work capacity and performance (iron in muscle (myoglobin) • Impaired immune function • Anemia - mild to severe, with poor oxygenation of tissues; late manifestation • Neurotransmitters may be impaired Approaches: • Food-based for prevention, fortification, and intake of iron-rich foods • Prophylactic iron in high-risk groups (pregnancy) • Iron therapy in anemic populations; i.e., young children and pregnancy • Eliminate hookworm and other parasites (schistosomiasis)

ZINC DEFICIENCY • Widespread globally • Hard to assess by usual means • Low absorption from plant-based diets (fiber and phytate block absorbtion) • Vital for skeletal growth • Key role in protein synthesis • Fetal growth • Key role in immune system: anti-infective, wound healing • Role in infant child activity and cognitive development Approach: • If suspicious, treat • Food-based: household use of animal foods (especially any kind of meat) • Germination, soaking, fermenting to reduce phytate in foods, which reduces absorption • There are some pharmaceutical trials - limited coverage

VITAMIN B12 DEFICIENCY • Seen in vegetarians • Key role in brain and CNS development • Key role in red blood cell formation • Role in immune function • Recently found to play a role in cognitive function in children • Low breast milk B12 is of risk to an infant Approach: Promote animal source foods in diet milk and or meat