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.