Source: Lectures 22 and 23 | Biology, University of Michigan
Difficulty: Introductory. No specific prerequisites.
Food insecurity affects roughly 14% of US households and exists as both overnutrition (excess energy-dense foods) and undernutrition (inadequate essential nutrients). Agriculture relies heavily on synthetic pesticides, which persist in the environment through biomagnification, while climate change threatens food security through extreme weather, crop failure, and disease spread. Foodborne illness, most commonly caused by norovirus, is largely preventable through basic hygiene and the four principles of food safety: clean, separate, cook, chill.
Food insecurity
A lack of secure access to sufficient amounts of safe and nutritious food.
Overnutrition
Excess intake of energy-dense foods at the expense of nutrient-dense foods. In simple terms, eating too many calories from junk food while missing out on vitamins and minerals.
Undernutrition
Inadequate intake of essential nutrients and often overall energy.
SNAP (Supplemental Nutrition Assistance Program)
A US federal programme that provides food-purchasing assistance to low-income individuals and families.
WIC (Special Supplemental Nutrition Program for Women, Infants and Children)
A US programme providing supplemental food, nutrition education, and referrals for pregnant women, new mothers, and young children.
NSLP (National School Lunch Program)
A federally assisted meal programme providing low-cost or free lunches to schoolchildren.
Sustainability
Using resources at rates that do not exceed the earth's capacity to replace them. Implies safety and security of the food supply, including biodiversity, water quality, and soil quality.
Biomagnification
The process by which lipid-soluble chemicals (e.g. pesticides like DDT) increase in concentration as they move up the food chain. Small organisms absorb a little; predators accumulate much more.
GMO (genetically modified organism)
An organism whose genetic material has been altered using genetic engineering. Common GM foods include corn, soybeans, rice, and tomatoes. The FDA regulates the safety of GM crops for human and animal consumption.
Foodborne infection
Illness caused by consuming food contaminated with live microorganisms (viruses, parasites, bacteria) that multiply in the intestines.
Foodborne intoxication
Illness caused by ingesting food that contains a toxin produced by bacteria or fungi. Toxins remain present even after cooking.
Norovirus
The most common cause of foodborne illness in the US, causing 19 to 21 million cases of stomach/intestinal inflammation annually. Transmitted through contact, contaminated surfaces, or contaminated food.
HACCP (Hazard Analysis and Critical Control Points)
A systematic food safety approach that prevents hazards by monitoring critical control points in food production. Federally required for the meat industry since 1998.
Irradiation
An FDA-approved food safety technique that does not affect nutrition, texture, taste, or radioactivity of food.
Cross contamination
The transfer of harmful microorganisms from one food (typically raw meat) to another, often through shared surfaces, utensils, or hands.
People lack secure access to sufficient safe and nutritious food
Exists as overnutrition (excess energy-dense foods) and undernutrition (inadequate essential nutrients)
US (2013): 85.7% food-secure households, 8.7% low food security, 5.6% very low food security
WIC: for women, infants, and children
NSLP: National School Lunch Program
SNAP: Supplemental Nutrition Assistance Program
Purpose: enhance access, availability, and affordability of nutritious foods
Popillia japonica: introduced to New Jersey in 1916, pest of 200 species
1950s and 1960s: insecticide boom; more chemicals applied than needed
Entomophobia contributes to over-application of chemical insecticides
Drawbacks of synthetic insecticides:
Kill pollinators, detritivores, and natural enemies
Small doses are lethal
Chemically stable, persist in the environment
Lipid-soluble, stored in fat, leading to biomagnification up the food chain
Many insect species (roughly 700) have developed resistance
DDT was used in the US to control mosquitoes until the 1960s
Using resources at rates that do not exceed the earth's capacity to replace them
Encompasses biodiversity, water quality, and soil quality
2014 report by the Center for Food Safety recommends: eating fresh unprocessed foods, buying local and in-season produce, choosing organic foods, eliminating industrial meat and dairy, reducing food waste
Climate: changes in temperature, precipitation, humidity, or wind lasting for an extended period
Weather: short-term atmospheric conditions
The time interval is the key difference
Sun's rays penetrate the atmosphere; earth's surface radiates heat
Greenhouse gases absorb and re-emit heat back toward earth
CO2 and other gases trap heat, keeping the earth warm
Injuries and fatalities
Heat stress, cardiovascular failure
Malnutrition, diarrhoea, harmful algal blooms
Anxiety, despair, depression, post-traumatic stress
Forced migration, civil conflict
Cholera, cryptosporidiosis, campylobacter, leptospirosis
Respiratory issues, allergies, malaria, dengue, Zika virus
Asthma, cardiovascular disease
Can increase yields and improve crop resistance to pests
Common GM foods: corn, soybeans, rice, tomatoes
FDA regulates GM crop safety for human and animal consumption
Potential benefits: increased vitamin/phytochemical content, improved taste/texture, disease and drought resistance, decreased pesticide use, increased yield, faster growth, more desirable traits, medicinal foods
Potential risks: harmful genetic changes, extinction of natural organisms, increased resistance of other pests, allergenic proteins in some people
Common symptoms: nausea, vomiting, abdominal cramps, diarrhoea
Vary in onset time, symptom duration, and potential consequences
Caused by consuming food contaminated with live microorganisms (viruses, parasites, bacteria)
Pathogen multiplies in the intestines
Transmission: faecal-oral route, cross contamination
Restaurants are associated with the highest rates of food poisoning outbreaks
19 to 21 million cases of stomach/intestinal inflammation per year
1.7 to 1.9 million outpatient visits, 400,000 emergency visits
56,000 to 71,000 hospitalisations, 570 to 800 deaths
Transmitted by: contact with an ill person, touching contaminated surfaces then mouth, consuming contaminated food or beverage
Foods commonly involved: leafy greens, fresh fruits, shellfish (oysters, scallops, clams)
Prevention: wash hands, clean surfaces, wash laundry, use gown and gloves, stay home when sick
Norovirus causes the most illnesses, but salmonella causes more hospitalisations
Caused by ingesting food containing a toxin (produced by bacteria or fungi)
Toxins remain present even after cooking
Most commonly caused by Staphylococcus aureus and Bacillus cereus
HACCP: prevents hazards, monitors critical control points. Federally required for meat industry since 1998.
Irradiation: FDA-approved, does not affect nutrition, texture, taste, or radioactivity
Clean: wash hands and surfaces often
Separate: keep raw meats apart from other foods
Cook: cook to recommended temperatures
Chill: refrigerate foods promptly
Perishable foods should never be left out more than two hours
Students sometimes confuse foodborne infection (live microorganisms multiply in the gut) with foodborne intoxication (preformed toxins in the food). The key distinction is that intoxication toxins survive cooking.
Students may assume norovirus causes the most hospitalisations. Norovirus causes the most total illnesses, but salmonella causes more hospitalisations.
Students often think irradiation makes food radioactive. It does not, and it does not change nutrition, texture, or taste.
Students may believe climate and weather are the same. The difference is the time interval: climate is long-term, weather is short-term.
⚠️ Restaurants are associated with the highest rates of food poisoning outbreaks.
⚠️ Norovirus: most illnesses. Salmonella: most hospitalisations.
⚠️ Foodborne intoxication is most commonly caused by Staphylococcus aureus and Bacillus cereus.
⚠️ Perishable foods should never be left out more than 2 hours.
⚠️ HACCP has been federally required for the meat industry since 1998.
⚠️ The difference between climate and weather is the time interval.
⚠️ Know the four food safety principles: clean, separate, cook, chill.
⚠️ Biomagnification: lipid-soluble chemicals increase in concentration up the food chain.
Fill in the blank: The difference between climate and weather is the _________. (time interval)
True or False: Irradiation of food makes it radioactive. (False)
Fill in the blank: Norovirus causes the most _______, but salmonella causes the most _______. (illnesses, hospitalisations)
True or False: Foodborne intoxication is caused by live pathogens multiplying in the intestines. (False, that is foodborne infection. Intoxication is caused by preformed toxins.)
Fill in the blank: Perishable foods should never be left out for more than _____ hours. (2)
Q: What is the difference between foodborne infection and foodborne intoxication?
A: Foodborne infection is caused by consuming live microorganisms (viruses, parasites, bacteria) that multiply in the intestines. Foodborne intoxication is caused by ingesting preformed toxins produced by bacteria or fungi; these toxins survive cooking.
Q: What are the four principles of food safety in the home?
A: Clean (wash hands and surfaces), separate (keep raw meats apart), cook (to recommended temperatures), chill (refrigerate promptly).
Q: Which setting is associated with the highest rates of foodborne illness outbreaks?
A: Restaurants.
Q: Name three potential benefits and two potential risks of genetically modified organisms.
A: Benefits include increased yield, disease/drought resistance, decreased pesticide use, improved nutritional content, and faster growth (any three). Risks include harmful genetic changes, extinction of natural organisms, increased resistance of other pests, and allergenic proteins (any two).
Q: What is biomagnification and why is it a concern with synthetic pesticides?
A: Biomagnification is the increasing concentration of lipid-soluble chemicals as they move up the food chain. Synthetic pesticides that are chemically stable and lipid-soluble get stored in fat tissue, so organisms higher in the food chain accumulate increasingly dangerous concentrations.
Food safety connects to Lecture 16 (Dietary Supplements), where FDA regulation, or lack thereof, is a recurring theme. The sustainability discussion ties to the broader dietary recommendations in Lectures 18 and 19 (Obesity and Weight Loss), where whole foods and Mediterranean diets were shown to produce better health outcomes. Climate change's impact on malnutrition and food security links back to the nutrient deficiency concerns raised in Lecture 20 (College Nutrition).
Food insecurity, overnutrition, undernutrition, SNAP, WIC, NSLP, sustainability, biomagnification, DDT, pesticides, insecticide resistance, GMO, genetically modified organisms, climate change, greenhouse gases, CO2, foodborne illness, foodborne infection, foodborne intoxication, norovirus, salmonella, Staphylococcus aureus, Bacillus cereus, HACCP, irradiation, cross contamination, food safety, clean separate cook chill, perishable foods, organic foods, food waste