Public Health & Nutrition Comprehensive Study Notes

Public Health: Core Principles & Vision

  • Vision: “Healthy People in Healthy Communities”
  • Mission:
    • Promote physical and mental health
    • Prevent disease, injury, and disability
  • Six “signature” roles of Public Health (PH):
    • Prevent epidemics & the spread of disease
    • Protect against environmental hazards
    • Prevent injuries
    • Promote & encourage healthy behaviors
    • Respond to disasters/assist community recovery
    • Assure the quality & accessibility of health services

Recent & Salient Health Threats

  • Global (2019–2020):
    • Coronavirus (COVID-19)
    • Vaccine hesitancy
    • Air pollution
    • Climate change
  • United States–specific events:
    • E-cigarette use (“vaping” epidemic)
    • Opioid crisis
    • Antibiotic & antimicrobial resistance
    • Hurricane Sandy (2012 – NJ/NY)
    • H1N1 influenza outbreak (2009)
    • HPV & cancer burden
    • Hurricane Katrina (2005 – LA & MS)
    • 9/11 terrorist attacks (2001 – NYC)

Mortality Landscape

  • Top-10 Causes of Death in the U.S. (approx. rank order)
    1. Heart disease
    2. Cancer
    3. Unintentional injuries
    4. Chronic lower-respiratory diseases (CLRD)
    5. Stroke (cerebrovascular disease)
    6. Alzheimer’s disease
    7. Diabetes mellitus
    8. Influenza & pneumonia
    9. Kidney disease (nephritis/nephrosis)
    10. Suicide

Three Pillars of Public Health Activity

  • Preventing disease
  • Prolonging life
  • Promoting health—for everyone, at every life stage
  • Financial, social & environmental angles:
    • \text{PH saves money + lives} via early detection, effective treatment & healthier environments.

Public Health vs. Clinical Medicine

  • Medicine: saves lives one at a time.
  • Public Health: saves millions at a time.
  • U.S. Life-Expectancy Gain:
    • 1900 ≈ 47.3\;\text{yrs}
    • 1996 ≈ 78.1\;\text{yrs}
    • Net ↑ ≈ 25\;\text{yrs} (majority credited to PH measures)

20th-Century U.S. PH Achievements (Top-10)

  • Vaccinations
  • Safer workplaces
  • Safer/healthier food
  • Motor-vehicle safety
  • Control of infectious diseases
  • Decline in coronary heart disease & stroke deaths
  • Family planning
  • Recognition of tobacco as health hazard
  • Healthier mothers & babies
  • Fluoridation of drinking water

Key Emerging 21st-Century Achievements

  • Vaccine-preventable disease control
  • Infectious-disease surveillance & response
  • Tobacco control (incl. e-cig regulation)
  • Maternal & infant health advances
  • Motor-vehicle fatality decline
  • Cardiovascular-disease prevention
  • Occupational safety expansion
  • Cancer prevention & screening
  • Childhood lead-poisoning prevention
  • Improved PH preparedness/response (all-hazards)

Public Health Functions & Essential Services

  • Three core functions:
    1. Assessment
    2. Policy development
    3. Assurance
  • 10 Essential Services (1994 Steering Committee):
    1. Monitor health status
    2. Diagnose & investigate health problems/hazards
    3. Inform, educate & empower the public
    4. Mobilize community partnerships
    5. Develop policies & plans
    6. Enforce laws & regulations
    7. Link people to needed services / assure care
    8. Assure a competent workforce
    9. Evaluate health services
    10. Research for new insights & solutions

Federal Public Health Responsibilities

  • Ensure all levels of gov’t have PH capability
  • Act when threats span states/regions/nation
  • Intervene when solutions exceed any single state’s jurisdiction
  • Provide assistance/resources when states lack expertise
  • Facilitate formulation of national PH goals

U.S. Insular Areas

  • 5 Territories: Puerto Rico, Guam, U.S. Virgin Islands, American Samoa, Commonwealth of the Northern Mariana Islands
  • 3 Freely Associated States (FAS): Republic of the Marshall Islands, Federated States of Micronesia, Republic of Palau
  • Challenges: geography, culture, economy, education, high morbidity/mortality
  • Federal strategies: tailor assistance, inter-agency coordination, place more federal staff in-region, pilot innovative initiatives
  • Traits of a Well-Functioning PH System: strong partnerships, effective communication, shared objectives, resource sharing, leadership, feedback loops across federal–state–local–tribal–territorial lines

Infectious Disease Primer

  • Myth vs. Fact: ~80 % of infectious diseases spread via hands → hand-washing is critical
  • Major Pathogen Classes & Examples:
    • Bacteria → strep throat, TB, cholera, tetanus, staph infection
    • Viruses → common cold, influenza, hepatitis, polio, rabies
    • Fungi → athlete’s foot, ringworm
    • Protozoa → malaria, amebic dysentery
    • Other: mites, lice, worms

Transmission Reservoirs & Pathways

  • Where pathogens live: blood, body fluids, urine, feces, vomit, saliva, tears, sweat, semen/vaginal fluid, food, water, pets, pests
  • How they spread:
    • Direct/indirect contact (touching people or contaminated surfaces)
    • Respiratory droplets (coughing, sneezing, talking)
    • Ingestion of contaminated food/water
    • Vector bites (mosquitoes, animals)
    • Entry via skin breaks or mucous membranes

High-Risk Populations

  • Infants, children, elders
  • Immunocompromised or chronically ill
  • Poor diet, poor hygiene, crowded living conditions
  • Over-tired or stressed individuals

Prevention Tips (Standard Precautions)

  • Hand-washing, respiratory etiquette (cough into sleeve/tissue)
  • Annual flu vaccination + other indicated vaccines (e.g., Hep B)
  • Stay home when ill; avoid sharing utensils/cups

Key Bloodborne/Common Infections

  • Bloodborne → HIV/AIDS, Hepatitis B & C
  • Other → staph skin infections, pneumonia, UTIs, Giardia (parasite), influenza, GI viral infections, chickenpox, measles, mumps

Nutrition Fundamentals

  • Definition: nutrients are substances required for growth, repair & energy; nutrition is both a biological and social science
  • Six Nutrient Classes: carbohydrates, fats (lipids), proteins, vitamins, minerals, water
  • Energy-Yielding Nutrients: carbs, fats, proteins → release calories during metabolism
    • 1 kilocalorie = 1000 calories (food Calorie)

Carbohydrates

  • Simple sugars: glucose, fructose, lactose, sucrose – quick energy; surplus stored as glycogen/fat
  • Complex carbs (starches): long glucose chains in breads, cereals, pasta, potatoes – slower, sustained energy
  • Dietary fiber:
    • Soluble → binds waste (oat bran, beans, apples, carrots)
    • Insoluble → adds bulk (whole grains, skins/seeds of produce)

Fats (Lipids)

  • Energy density: 1 g fat ≈ 9\;\text{kcal} (≈ >2× carbs/protein at 4\;\text{kcal}/g)
  • Types:
    • Saturated (solid ↔ tropical oils, butter) → ↑ LDL, CVD risk
    • Unsaturated
    • Monounsaturated (olive, peanut oil)
    • Polyunsaturated (corn, soybean, fish oils)
  • Cholesterol:
    • Endogenous synthesis (liver) + diet (animal products)
    • Transported as LDL ("bad") & HDL ("good")
    • Exercise ↑ HDL; low-fat diets ↓ LDL

Proteins

  • Build/repair tissues; critical for hemoglobin, enzymes, antibodies
  • Composed of 20 amino acids (9 essential, 11 non-essential)

Regulatory Nutrients

  • Vitamins: fat-soluble (A, D, E, K) & water-soluble (B-complex, C)
    • Examples:
    • Vitamin A → vision/bone; toxicity causes hair loss/headache; deficiency → night blindness
    • Vitamin D → Ca/P absorption; deficiency → rickets; toxicity → calcification
    • Vitamin E → RBC protection; deficiency → anemia
    • Vitamin K → blood clotting; deficiency → hemorrhage (newborn risk)
  • Minerals:
    • Major → calcium, phosphorus, magnesium, potassium, sulfur, sodium, chlorine
    • Calcium: bone, nerve; deficiency → osteoporosis
    • Sodium/Potassium: fluid balance; excess Na → hypertension; low K → arrhythmia
    • Trace → iron, iodine, manganese, zinc, copper, fluorine
    • Iron: hemoglobin; deficiency → anemia
    • Iodine: thyroid hormones; deficiency → goiter
  • Water: most vital; ~2–3 qt lost daily → must be replenished; solvent for nutrients; regulates temperature; cushions organs
    • Electrolytes (ions) maintain water balance

Interpreting the Nutrition Label

  • Key Questions:
    • Actual calories per serving? (Low = 40, Moderate = 100, High = 400)
    • Which nutrients to limit vs. get enough of?
    • How to judge %DV (Daily Value) as high (>20 %) or low (<5 %)?
    • Which nutrients lack a %DV (e.g., trans fat, added sugars)?
  • Daily Goals (2,000 kcal baseline):
    • Limit to < 100 % DV: total fat (65 g), saturated fat (20 g), cholesterol (300 mg), sodium (2400 mg)
    • Reach ≈ 100 % DV: dietary fiber (25 g), Vitamins A & C, calcium (1000 mg), iron
    • Example calcium calculus: 100\%\;\text{DV} = 1000\;\text{mg} → 1 cup milk has 30 % DV = 300\;\text{mg}.

Ethical, Philosophical & Practical Implications

  • Equity: “No one left out” – PH strives for universality, especially vulnerable groups (children, elders, low-income, geographically isolated)
  • Systems Thinking: success requires multisectoral partnerships, continuous feedback loops, resource sharing & culturally competent policies.
  • Cost–Benefit: Preventive care & early intervention save both lives and money; long-term societal ROI includes reduced healthcare spending, increased productivity & healthier environments.
  • Individual Responsibility vs. Collective Action: Hand-washing, vaccination, nutrition choices (micro-level) align with policy, infrastructure, and education (macro-level) to yield population health gains.