Nutrition: Environmental Study Questions Synopsis: The natural world provides the food we eat. In the pursuit food what type "footprint" are we leaving on the environment? This lecture further integrates lessons learned this semester by describing several strategies that sustain the environment & human health including: 1. Eat local 2. Support sustainable agriculture 3. Eat whole, minimally-processed foods 4. Reduce energy use in transportation 5. Use your economic vote Textbook readings: Pages 536, 540-550 I. Overview a. Food is that part the environment that you eat - environment becomes you b. We can lessen the environmental impact food production i. U.S. has 6% the world's population & uses 30% its resources [resource use comparison] Environmental impact food production & dietary choice Where do resources go? Compare the resources used by the average Chinese to those used by the average American. Which nation as a whole uses more resources? resource use: USA > China - resource use ~ lifestyle ( pop.) - nutritional benefits: whole minimally processed foods - nutrient losses: processing (e.g. fiber, vitamins & esp. minerals, phytochemicals) - overprocessed diets nutrient loss Transportation (energy) Where does Wisconsin's winter produce come from? It's bread? How does regional specialization production increase the energy cost transportation? - cheese from Wisconsin: concentrated food - shipped to arid places (e.g. desert in Southwest) - low shipping cost for high concentrated food (e.g. cheese) - top fruit: bananas, should be apples - less fossil energy less climate change - smaller, more efficient cars & exercise (energy/kcal balance) - walk & bike for transportation energy use in society, personal energy expenditure (less obesity) - need more bike paths, green spaces, trails Packaging Consider the resources used in packaging. How do you think home food preparation compares to fast food? Which do you think is more resource efficient? Home food preparation is less packaged compared to fast food & is more resource efficient. - processing highly packaged (e.g. styrofoam, plastic, paper)
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packages hard to recycle ( bottles & cans) garbage to landfill
wasted energy &
Feed conversion What do we mean by the energy cost feed conversion? What kind food is the most energy efficient to produce? The least? energy cost feed conversion: no. lbs. feed for animals/produce no. lbs. food - most efficient to produce: produce, whatever grown - least efficient to produce: meat, whatever fed Fertilizer Is there an energy cost to chemical fertilizers? Yes, there is energy cost to chemical fertilizers. - fertilizer: energy-intensive process capturing nitrogen in air - nitrogen: limiting factor plant growth Topsoil How is topsoil lost? Why might this be a problem? Topsoil lost through erosion--lose soil blown/washed away. - cause: poor crop mgmt. ( rotation), deforestation Water Is there a cost to relying on irrigation for crop production? Yes, there is cost to relying on irrigation for crop production. - irrigation (from rainfall in Wisconsin) - fossil water (from glacier, not replenished) in West Fuel Fuel is used in food production. How? Fuel is energy use for transportation. Environmental degradation Climate change What do we mean by climate change? What do we believe may cause it? Where does this come from? Increased carbon dioxide from increased fossil fuel production contributes to global warming & climate change. - energy fossil fuel carbon dioxide 2 - CO green house gas contributes to global warming, climate change affects agriculture - benefits to sustainable ag. practices: energy use, toxic pollution Toxic pollution Are toxic pesticides persistent in the environment? Yes, toxic pesticides are persistent in environment. Health Effects Organochlorines What problems have been suggested to have a link to pesticides? Suggested problems linked to chemical pesticides are cancer & birth defects.
Bioaccumulation toxins What do we mean by bioaccumulation toxins? Which foods tend to contain the highest levels toxins? Why? - bioaccumulation toxins: (fat soluble, stored but not excreted) toxic substances & heavy metals (lead & mercury) tend to build up in food supply - PCB evaporating from Lake Michigan rain grass consumed by cattle PCB concentrated, not excreted high concentration in cow - also: mercury build up in oceanic environment high concentration in sword fish & tuna (fish) Nutrient content Can different production methods yield foods w/ different nutrient contents? Yes, diff. production methods yield foods w/ diff. nutrient contents via manipulation soil, fertilizer, etc. - e.g. soil near oceans: iodine concentration II. Strategy 1: Eat local a. Environmental benefits local production b. Eating seasonally c. Nutritional benefits d. Some exceptions e. Access local to food III. Strategy 2: Support sustainable agriculture a. Renewable resources b. Soil conservation c. Fewer chemical inputs d. Changes in animal production e. Water resources & irrigation f. Benefits sustainable agriculture [bio-accumulation] g. Accessing sustainably-produced food h. Same sources as for local food IV. Strategy 3: Eat whole, minimally processed foods a. Packaging waste b. Nutrient losses in processing c. Food should resemble its source V. Strategy 4: Reduce energy use in transportation a. Less energy, less climate change b. Smaller, more efficient cars c. Biofuels d. Walk & bike for transportation VI. Strategy 5: Use your economic vote a. Support what you believe in b. Producers need markets c. Create a demand & it will be filled
Dollar vote: consumers (not farmers) to create market, demand for locally produced foods Reducing environmental costs Definition sustainable What is a sustainable system? Sustainable agriculture sys. relies on: - renewable resources (biofuels, wind, sun) - energy conservation, reduced fossil fuels - soil conservation (cropping sys. that preserve soil) - fewer chemical inputs (fertilizers, pesticides) Sustainable agriculture How can reliance on pesticides be reduced? Reliance on pesticides can be reduced by: - crop rotation to reduce pest buildup in soil - biological controls for pests (e.g. airplanes flying low to spray bacteria that attacks gypsy moths) - integrated pest mgmt. techniques: chem. pesticides in highly managed fashion--minimal amts. @ right time (due to energy savings) - sustainable agriculture concentrated to dispersed animal production Are there ways to improve soil fertility using fewer chemical fertilizers? Yes, alternatives to improve soil fertility using fewer chemical fertilizers: - grow legumes/beans (only plants that can capture nitrogen in air) - grow alfalfa & clover, plow in soil nitrogen used by next crop Are there standards for organic food production? Yes, there are standards for organic food production: - use antibiotics & hormones on livestock - use chemical pesticides & fertilizers on plants sustainably produced food: feed ranged beef (grass-fed vs. grain-fed), chicken; organically produced foods health benefits to organic foods: bioaccumulation possible, residue environmental benefits: incorporates sustainable practices (less impt. than eating locally produced food) found in: farmer's markets, CSAs, food co-ops
Local production How can local production save energy? Eat locally produced food is most significant single act to reduce resources - local production energy use for transportation, benefits to supporting local economies - eating seasonally variety foods, nutritional benefits (fresher food better nutrition) What might be some advantages to a diversified food supply? diversified food supply food variety nutritional benefits
How can one get access to locally-produced food? - biggest issue: access to locally-produced foods; typically not found in supermarkets One can get access to locally-produced food: - Farmer's markets: high quality & wide variety food @ good price - CSA, community-supported agriculture (e.g. food co-ops): consumer buys share farmer's production (e.g. produce & meat); flat fee w/ deliveries selections in season high quality & wide variety food @ good price; convenient for consumer; money upfront for farmer + guaranteed markets; cut out middleman costs Might there be quality advantages to local food? How? Yes, there are quality advantages to local food in quality (high), variety (wide), & price (low). Eat seasonally What do we mean by eating seasonally? What are some advantages eating seasonal foods? - eating seasonally variety foods, nutritional benefits (fresher food better nutrition) - exceptions: dry, arid places not well-suited to food production Garden Can home garden be a significant source food? Yes, home garden be a significant source food. - garden: learn food, how it's grown, connect w/ food supply; educational - statistic: 20-30% vegetables from home gardens Rely more on plant foods What are some benefits increasing the proportion plant foods in one's diet? Some benefits increasing proportion plant foods in one's diet: - nutrient density ( nutrient/kcal) (e.g. fiber, phytonutrients) - rates chronic disease Role animals What ability do ruminant animals have that allows them to produce food in marginal environments? To produce food, graze ruminant animals in marginal environments. - ruminant animals: cattle, sheep, goats w/ 4-chambered stomachs digest indigestible CHO/fiber - use cellulose: bacteria produces cellulase enzyme to break down cellulose What nutritional roles can they play in the diet? nutritional roles in diet: cellulose in meat & milk nutritional benefits: B-12, iron (also plant sources w/ vit. C to enhance absorption), calcium (dairy products)