MS130 - Biology
return to home page
Pete Markiewicz
Week 10
Web links week 10 - The human body, health, nutrition
The good news (from "Millennials
and Pop Culture", Lifecourse.com):
Thanks to the growing protectiveness of parents, schools, and communities,
today’s Millennials have the lowest rates of mortality and disease of any
generation in history.
Not so good news (from
the same source)
In today’s youth
environment, it is as common for a collegian or high school student to struggle
with body-altering issues as it was for a Boomer to struggle with mind-altering
ones.
Health, nutrition and diseases
Problem - lots of health-related information is available today, but much of it is incorrect or deliberately misleading,
especially information on the Internet
Rating the quality of health-related websites
http://bmj.bmjjournals.com/cgi/content/full/324/7337/598
Examples of health-related websites
Nutrition
People eat to get enough energy to move - if you eat less than you
burn in a given period of time, you die
Food is dis-assembled down to bio-molecules during digestion
- Proteins - break down to amino acids, form enzymes, muscles
- Fats - break down to fatty acids, cell membranes and burned for
energy
- Carbohydrates - break down to sugars, burned for energy
- Antioxidants - reduce "superoxide" (form of oxygen) damage to tissue during metabolism
- Vitamins -
used as active molecule in enzymes
Example for
Niacin (B3) in enzyme active site (NADH)
http://bioweb.wku.edu/courses/BIOL115/Wyatt/Biochem/Protein/Active%20site.htm
- Minerals - (e.g., calcium) used to construct bones, teeth, active atoms in an enzyme
Calories - a measure of the heat energy produced by food or exertion
The bio-molecules are re-assembled into your body after they are absorbed
- Amino acids - > enzymes and other proteins
- Fatty acids -> fats
- Carbohydrates -> fats
- Antioxidants -> integrated into cells
- Vitamins -> integrated into active site of enzyme
- Minerals -> deposited by specialized cells to form bones, teeth
Why are people overweight?
Evolution of diet - http://www.healthspan.co.uk/articles/article.aspx?Id=153&ct=true
- In past history - "feast or famine" was typical of human society
- People had to put more energy into finding food (hunter-gatherer
lifestyle)
- People were attracted to high-calorie food since it was rare
- We try to eat lots of fat and carbohydrates because we are
"programmed" to do so
- People had to expend effort to process their food into eatable forms
- Food had more fiber, indigestable, even toxic components
- People processed all their own food by hand
- Now
- We get all the food we want with little expenditure of energy
(supermarket)
- Food is pre-processed, pre-cooked (compare Corn Flakes with corn)
- Machines do our food processing (less personal effort) even when we
cook
- We rely on other people to process our food (dining out)
- Soft food (McDonald's) may be eaten by toothless seniors gumming
their burgers
More about obesity
- "Normal" percentages of body fat
- Normal male - 20%
- Male athlete - 5% - 10%
- Normal female - 20 - 27% = 10% essential, 15% storage
- Female athlete - 15% (very hard to get this thin)
- Definition of overweight and obese
- Body Mass chart
- Obesity levels in the US
- Change in obesity levels over time
- Generations and obesity ("Millennial" generation born after 1982 have it the worst)
- Health factors related to obesity
- Hypertension
- Dyslipidemia (for example, high total cholesterol or high levels of triglycerides)
- Type 2 diabetes
- Coronary heart disease
- Stroke
- Gallbladder disease
- Osteoarthritis
- Sleep apnea and respiratory problems
- Some cancers (endometrial, breast, and colon)
- How to reduce obesity- lose fat
- NUMBER ONE - Exercise!!!! play real game instead of videogame!!!
- NUMBER TWO - Reduce intake of high-fat foods (e.g. fast food)
- NUMBER THREE - Gastric bypass surgery - smaller stomach reduces desire, holds less food
- How NOT to reduce obesity
- lose fat AND muscle both!
- Value of "diverse" body types in evolution
"Natural" and "organic" versus processed food
- "Natural" is a near-meaningless term - IGNORE IT!
- "Toxic" is a near-meaningless term - IGNORE IT!
- "Processed" food may mean the following
- "Factory farming" - production of food via "factory farming" of
large areas by machines
- Farms owned by corporations (< 1% of US population does all
farming)
- Extensive use of oil-derived fertilizer for massive crop yields
- Extensive use of oil-derived pesticides to reduce crop loss
- Physical processing of food (cooking, frying, coloring)
- Animals grown under accelerated conditions
- Hormones added to stimulate body growth, milk production
- Use of antibiotics in animal feed to increase growth
- Animals fed slaughterhouse refuse in their meal (cannibals)
- Inhuman animal growth (e.g chickens unable to move with beaks
cut off)
- Use of genetically-engineered strains - selective breeding
- "Giant" fruit and vegetable strains which are impressive in
supermarket, taste bland
- Fruit/vegetables with ultra-tough skins to survive long
transport (rubber tomatoes)
- Use of genetically-engineered crops - direct DNA manipulation
- Increased resistance to pesticides
- Ability to "fix" nitrogen directly
- Vitamins produced by common plant (e.g. carotene in rice)
- Food additives (usually antioxidants - not always bad)
- "Designer" food form requiring lots of mechanical processing
(cereal, twinkies)
- "Organic" food may mean the following
- Grown without pesticides
- Lacking added vitamins and minerals
- Requiring extensive human labor
- Use of heirloom plant and animal strains - genetically engineered,
but via selective breeding instead of DNA manipulation
- Breed for taste
- Bitterness not bred out (more antioxidants)
- Leaner meat in animals (also tougher)
- Use of plants without bitter (antioxidants)/fiberous parts removed
- Allowing normal behavioral patterns for food animals ("free range")
Organic food will ALWAYS be more expensive (2x - 10x more)
- No pesticides = More pest damage, partial loss of crop
- No artificial (oil-based) fertilizer = Less food grown per acre
- No "factory farms" = More people needed to produce same food
- Free range = more land, care needed to raise farm animals "naturally"
- Free range = Animals have lower body weight, tougher meat
- Heirloom fruits and vegetables = can't be transported long distances - no
"3,000 mile sandwich", some areas would NEVER be able to have
purely organic food
"Good" and "evil" foods
Society defines foods as "good" or "evil" based on irrational
(non-scientific) criteria. These may be religious dietary restrictions (e.g.
Kosher), philosophical/lifestyle restrictions (Vegan) or over-focus on the good
or bad aspects of a single food type.
- Fats/lipids (were "evil", now "good" in some cases)
- Fat has 2x the energy of other foods for a given weight
- Fat is necessary to build cell membranes, create hormones (e.g. sex
hormones)
- Body naturally produces many lipids (majority of cholesterol
produced internally)
- Saturated fat
- Found in animal (beef) and plant (palm oil) products
- Implicated in heart disease
- Unsaturated fat
- Oxidized fat
- Unsaturated fat combined with oxygen
- Formed by extensive high-temperature cooking (e.g. oil used to fry
for long periods of time)
- "Rancid" oil - may change color
- VERY BAD for body
- Fat in the body
- Carried in High-Density Lipoprotein (HDL) and Low-Density
Lipoprotein (LDL) complexes
- High HDL levels are good, high LDL levels are bad
- HDL may be raised by exercise
- Carbohydrates (were "good", now "evil")
- All carbohydrates go to "sugar" inside your body!
- Complex carbohydrates (e.g. yam carbs) take many hours to convert to
sugar
- Simple carbohydrates (sugar) give immediate "sugar rush"
- Sugar spikes may contribute to loss of insulin sensitivity
(diabetes) in older people
- Protein (usually "good" sometimes "evil")
- Complex protein builds muscles, esp. high-protein diets
- Simple protein (amino acid) diets can be life-threatening
- Antioxidants - currently "good"
- Other vitamins - typically form the "active site" of a protein enzyme
Drugs
Prescription drugs
http://www.rci.rutgers.edu/~lwh/drugs/types.htm
Illicit drugs
http://www.aic.gov.au/research/drugs/types/
http://www.tpoftampa.com/html/programs/residential/chem_dep/types_of_drugs/
- Alcoholism
- ADD
- Aging - People are "designed" to die (not steal food from their grandchildren)
- Cancer
- Stem cells
- Infectious Diseases
- Noravirus "cruise ship"
- Common enteric diseases
- Colitis
- Mononucleosis
- STDs (sexually transmitted diseases)
- Flus, colds
- Asthma
- Pandemics
- Sex
GO TO BEGINNING OF COURSE
