critical thinking in food safety thomas j. montville
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Critical thinking in food safety
Thomas J. Montville
______________STATE UNIVERSITY OF NEW JERSEY
RUTGERSDEPARTMENT OF FOOD SCIENCE
Montville, IFT 2004 2
This lecture will help you …
gain confidence in “sorting out the numbers.” sort and evaluate claims and counter claims. help you be a defacto spokesperson (for
something).
______________STATE UNIVERSITY OF NEW JERSEY
RUTGERSDEPARTMENT OF FOOD SCIENCE
Montville, IFT 2004 3
You will be (are) a defacto spokesperson – FS/Nutrition Food companies are filling our food with
cancer causing poisons. Food is cheap because all large food
companies are getting huge government subsidies.
Natural food is healthier and more nutritious than food made by Agribuisness.
etc., etc.
You will be (are) a de facto spokesperson – FS/Nutrition Food companies are filling
our food with cancer causing poisons.
Food is cheap because all large food companies are getting huge government subsidies.
Natural food is healthier and more nutritious than food made by Agribuisness.
etc., etc.
?
?
?
?
What’s the harm in misrepresent in facts? False sense of security- can cause bigger problems
Bigger risks ignored – or incurred. We drink bottled water due to worries about municipal water (pesticides, cancer, heavy metals). But bottled has few standards,Wastes water in manufacturingMay have BPA.
Bigger problems than water; obesity. Focuses on food, rather than exercise.
Increased costsUnnecessary, and Ineffective Testing (McDonalds)Organic food costs 67% moreEnvironmental damage of packaging vs. additivesBiotech foods – cheaper (at least on the surface), may be better for the environment. (Nuclear power vs coal)
______________STATE UNIVERSITY OF NEW JERSEY
RUTGERSDEPARTMENT OF FOOD SCIENCE
Montville, IFT 2004 6
Are we spending enough on food safety?
How much are we spending?
USDA $797 million FDA $ 90 million Industry $ 90 million**Total $997~ 1,000 million
What’s the first two things you should as about these numbers?
Google Guess
______________STATE UNIVERSITY OF NEW JERSEY
RUTGERSDEPARTMENT OF FOOD SCIENCE
Montville, IFT 2004 7
Are we spending enough on food safety?Total spent $997~ 1,000 million
Basis of comparisonPopulation of U.S. (300 million) $ 3 per person# Illness (76 million) ~ $ 12 per illness# Death (5,000) ~ $ 20 per death$ Value of Food Industry $ 3.2 trillion109/1012 = x/100 10% of food dollars
Is this enough?
Google Guess
______________STATE UNIVERSITY OF NEW JERSEY
RUTGERSDEPARTMENT OF FOOD SCIENCE
Montville, IFT 2004 8
Regulations result from “the facts” derived from
“the best science available” economics practicality compromise politics
The problem with “facts”….
fact can be very dull (Inconvenient Truth) facts require interpretation Try to get at the data underneath “the facts”.
Beware of statistics – try to get at the underlying numbers*Beware of ratios:The increased use of food additives, has caused the % of childhood deaths caused by cancer has increased steadily over the last 100 years.
*Beware of % and “fold.” The data: Incidence of cancer increased from 1 in 1,000,000 to
2 in 1,000,000.The buzz: 2-fold increase in cancer. Cancer up 100%.
______________STATE UNIVERSITY OF NEW JERSEY
RUTGERSDEPARTMENT OF FOOD SCIENCE
Montville, IFT 2004 10
Look for the grain of truth. Take it with a grain of salt.
______________STATE UNIVERSITY OF NEW JERSEY
RUTGERSDEPARTMENT OF FOOD SCIENCE
Montville, IFT 2004 11
Examine % of children dying of cancer. Absolute number (cases/100,000 deaths) Infectious disease , infant mortality , industrial accidents , malnutrition
Absolute number (cases/100,000 deaths) of cancer cases remains unchanged.
Therefore % due to cancer .
Stats based on ratios can change because of numerator (top) or denominator (bottom).
______________STATE UNIVERSITY OF NEW JERSEY
RUTGERSDEPARTMENT OF FOOD SCIENCE
Montville, IFT 2004 12
An important digression on “number literacy”
One can’t explain what one doesn’t understand.
______________STATE UNIVERSITY OF NEW JERSEY
RUTGERSDEPARTMENT OF FOOD SCIENCE
Montville, IFT 2004 13
Think through the premiseHomework #1
In Defense of Food, Michael Pollon stated that the average American consumes 300 more calories per day than they did in 1980.
Is this credible?(3,500 calories = 1 pound)
______________STATE UNIVERSITY OF NEW JERSEY
RUTGERSDEPARTMENT OF FOOD SCIENCE
Montville, IFT 2004 14
Think through the premiseHomework #2
It has been stated* that the American diet is so bad that the average American has gained 10 pounds since 1990. *Do not link this to the previous example.
Is the weight gain a credible number? Does it constitute a real problem? How many excess calories per day would it
take to cause this weight gain? Is there a non-dietary solution to this problem?
______________STATE UNIVERSITY OF NEW JERSEY
RUTGERSDEPARTMENT OF FOOD SCIENCE
Montville, IFT 2004 15
Homework # 3, a premise that looks good on the surface.
In Defense of Food, Michael Pollon suggests that many of our problems due to the low cost of food. The US pay 10% of income on food while the French and Italians pay 15%. We’d be healthier if we increased the amount we paid for food by 50%.
What do you think of this? Please do some research and use facts to support your opinion.
______________STATE UNIVERSITY OF NEW JERSEY
RUTGERSDEPARTMENT OF FOOD SCIENCE
Montville, IFT 2004 16
Approximate
Approximate
Approximate
And identify or qualify your statement as “an approximate” or “within an order of magnitude.”
Cheat Approximate Scientific Units(It’s better to have an approximation that you understand than an exact number that is incomprehensible.)
30 grams ~ 1 ounce
500 g ~ 1 pound;
1,000 grams (1 kilo) ~ 2 pounds
(These are “off” by 10%)
1 liter ~ 1 quart
1 meter ~ 1 yard ~ 3 feet.
Altitude of San Madres is 3000 meters ~ 9,000 feet.
1 nautical mile ~ 1 statute (regular) mile
______________STATE UNIVERSITY OF NEW JERSEY
RUTGERSDEPARTMENT OF FOOD SCIENCE
Montville, IFT 2004 18
ppm is tiny – 1 inch in 16 miles
ppb is tinier- 1 cent in ten million dollars
“fecal coliform” is not “feces”
Under
Understanding the language.
______________STATE UNIVERSITY OF NEW JERSEY
RUTGERSDEPARTMENT OF FOOD SCIENCE
Montville, IFT 2004 19
False reasoning:
Furfural causes cancer
Bread contains furfural
Eating Bread Causes CancerEating Bread Causes Cancer
______________STATE UNIVERSITY OF NEW JERSEY
RUTGERSDEPARTMENT OF FOOD SCIENCE
Montville, IFT 2004 20
•1 slice white bread contains 167 µg (micrograms) of furfural.
•Rodent carcinogenic dose of furfural = 197 mg (milligrams)/kg (kilogram) body wt/day = 197,000 µg/kg/day. (1 mg = 1,000 ug)
•Equivalent human dose, 70 kg (150 lb) person = 197,000 x 70 ÷ 167 = 82,600 slices of bread82,600 slices of bread(dose) x (weight in kg) ÷ (amount per slice of bread) = slices of bread
DoesDoes eating bread cause cancer?
______________STATE UNIVERSITY OF NEW JERSEY
RUTGERSDEPARTMENT OF FOOD SCIENCE
Montville, IFT 2004 21
TOne (political) case studies from the annals of the FDA’s Food Advisory Committee
Note: An expert need not be a toxicologists, but must know how to think.
______________STATE UNIVERSITY OF NEW JERSEY
RUTGERSDEPARTMENT OF FOOD SCIENCE
Montville, IFT 2004 22
Patulin in Apple JuiceWould limiting patulin in apple juice to
50 ppb protect public?
U.S. apple industry in favor of this regulation. (Why?) Several issues- -Does the public need to be protected?-How much of the population should be protected? -Will 50 ppm be enough? (Why not “zero?”)
______________STATE UNIVERSITY OF NEW JERSEY
RUTGERSDEPARTMENT OF FOOD SCIENCE
Montville, IFT 2004 23
Patulin in Apple JuiceWould limiting patulin in apple juice to
50 ppb protect public?
NoOservableEffectLevel (NOEL) = 0.3 mg/kg bw per week
Add 100-fold safety factor
Provisional Max Tolerated Daily Intake (PMTDI) = 0.43ug/kg bw per day
______________STATE UNIVERSITY OF NEW JERSEY
RUTGERSDEPARTMENT OF FOOD SCIENCE
Montville, IFT 2004 24
Patulin in Apple JuiceWould limiting patulin in apple juice to
50 ppb protect public?
NoOservableEffectLevel (NOEL) = 0.3 mg/kg bw per week
Add 100-fold safety factor
Provisional Max Tolerated Daily Intake (PMTDI) = 0.43ug/kg bw per day
If a juice is 100% over the PMTDI, is it really dangerous?
Juice Samples from Current Production
Age Group
Ave. Juice Intake
(g/person/d)
Ave Patulin Exposure
(µg/kg-bw/d)
90th %
Juice Intake (g/p/d)
90th %
Patulin Exposure (µg/kg bw/d)
All ages
200 0.094 250 0.22
1 -2 years
216 0.58 434 1.3
<1 year
128 0.50 372 1.1
Ae Group
Mean Apple Juice Intake (g/p/d)
Mean Patulin Exposure (µg/kg bw/d)
90th Percentile Apple Juice
Intake (g/p/d)
90th Percentile Apple Patulin
Exposure (µg/kg bw/d)
All ages
200 0.031 250 0.078
Patulin Data Analysis
Remember, PMTDIRemember, PMTDI = 0.43 ug/kg bw/d
Is a regulation needed?
Patulin Data Analysis
Without regulation
All age groups 90% of population consumes < 0.22 ug/kg bw/dayNo need for regulation
1-2 year olds90% of population consumes < 15 ounces juice
consumes ~ 1.3 ug/kg per dayRegulation needed
______________STATE UNIVERSITY OF NEW JERSEY
RUTGERSDEPARTMENT OF FOOD SCIENCE
Montville, IFT 2004 27
Food Advisory Committee ConcernsAdvisory
Committee:Input data
15 ounces seemed “low”
What is consumption beyond 90% of the population?
Is it enough to protect 90% of the children?
Mix of “regular” and “baby food” apple juice?
Exclude Data for Juice Samples with Patulin > 50 ug/kg dAge
Group
Ave. Juice Intake
(g/person/d)
Ave Patulin Exposure
(µg/kg bw/d)
90th %
Juice Intake (g/p/d)
90th %
Patulin Exposure (µg/kg bw/d)
All ages
200 0.094 0.031 250 0.22 0.078
1 -2 years
216 0.58 0.17 434 (15 ounces)(15 ounces) 1.3 0.42
<1 year
128 0.50 0.13 372 1.1 0.38 OK?
Age Group
Mean Apple Juice Intake (g/p/d)
Mean Patulin Exposure (µg/kg bw/d)
90th Percentile Apple Juice
Intake (g/p/d)
90th Percentile Apple Patulin
Exposure (µg/kg bw/d)
All ages
200 250
Patulin Data Analysis
______________STATE UNIVERSITY OF NEW JERSEY
RUTGERSDEPARTMENT OF FOOD SCIENCE
Montville, IFT 2004 29
No Juice Samples ExcludedSamples > 50 ug/kg Excluded REVISED AFTER FAC CONCERNS
Age Group
Ave. Juice Intake
(g/person/d)
Ave Patulin Exposure
(µg/kg bw/d)
90th %
Juice Intake (g/p/d)
90th %
Patulin Exposure (µg/kg bw/d)
All ages
200 0.094 0.031 0.04 250 0.22 0.078 0.10
1 -2 years
216 0.58 0.17 0.22 434 1.3 0.42 0.67
<1 year
128 0.50 0.13 0.13 372 1.1 0.38 0.27
Age Group
Mean Apple Juice Intake (g/p/d)
Mean Patulin Exposure (µg/kg bw/d)
90th Percentile Apple Juice
Intake (g/p/d)
90th Percentile Apple Patulin
Exposure (µg/kg bw/d)
All ages
200 250
Patulin Data Analysis
Patulin Data Analysis
With regulation excluding juice with >50 ppb
1-2 year olds:
90% of population consumes < 0.67 ug/kg per day
(still higher than 0.43 ug/kg per day PMDTI)
FDA Regulatory Conclusion:
50 ppb in juice gives adequate protection
• “All Age” lifetime consumption gives 400-fold safety factor.• 1-2 year old exposure slightly > PTDI,
but has 64-fold safety factor.• 1- 2 year old exposure levels occur for limited part of lifetime, therefore acceptable.•Testing methodology would not support limit <50 ppb.
Data interpreted three ways!
______________STATE UNIVERSITY OF NEW JERSEY
RUTGERSDEPARTMENT OF FOOD SCIENCE
Montville, IFT 2004 32
Food Fads, Facts, and Politics
How to Sort Them Out
How to sort it out1. Consider the source
a. “Peer-reviewed” scientific literature, popular press or web site?
b. Credentials of the scientist – have they ever published anything in the field? (Check Google Scholar)
c. Follow the money (or agenda) ((Not always bad, if drug company won’t fund the research, who
will?)) (((I’ve taken money from the food industry.)))
______________STATE UNIVERSITY OF NEW JERSEY
RUTGERSDEPARTMENT OF FOOD SCIENCE
Montville, IFT 2004 34
How to sort it out
2. Look for qualifiers and generalizations:might, can, possibly, potential, up to, etc
______________STATE UNIVERSITY OF NEW JERSEY
RUTGERSDEPARTMENT OF FOOD SCIENCE
Montville, IFT 2004 35
How to sort it out
3. Beware of Emotional Anecdotes
______________STATE UNIVERSITY OF NEW JERSEY
RUTGERSDEPARTMENT OF FOOD SCIENCE
Montville, IFT 2004 37
How to sort it out
4. Correlation is not causationThere is a high correlation between
eating pickles and dying.Everyone who has ever eaten a pickle died.
______________STATE UNIVERSITY OF NEW JERSEY
RUTGERSDEPARTMENT OF FOOD SCIENCE
Montville, IFT 2004 38
How to sort it out
5. Be number literateIt’s mostly addition, subtraction multiplication, and division.
______________STATE UNIVERSITY OF NEW JERSEY
RUTGERSDEPARTMENT OF FOOD SCIENCE
Montville, IFT 2004 39
“The dosedose makes the poison.”
Dose = concentration x intake
______________STATE UNIVERSITY OF NEW JERSEY
RUTGERSDEPARTMENT OF FOOD SCIENCE
Montville, IFT 2004 40
Too much of a “safe” thing can kill you.
“Woman dies from drinking tap water”
Excessive water consumption can cause hyponatraemic encephalopathy.
A little bit of poison can cure you.
Before After
Beware of the
6. Precautionary Principle
“If we’re not 100% sure, let’s wait.”Also stated:
“Absence of (harmful) evidence absence of risk.”
but Zero risk does not exist.
ipods, cell phones, computer screens
______________STATE UNIVERSITY OF NEW JERSEY
RUTGERSDEPARTMENT OF FOOD SCIENCE
Montville, IFT 2004 43
The “Precautionary Principle”
Ignores potential benefits of new technology. Diverts resources from real problems to
hypothetical ones. Makes hypothetical concerns more important
than concrete benefits.
______________STATE UNIVERSITY OF NEW JERSEY
RUTGERSDEPARTMENT OF FOOD SCIENCE
Montville, IFT 2004 44
What drives people crazy?
Concern = control x risk
(Risk = hazard x probability)
______________STATE UNIVERSITY OF NEW JERSEY
RUTGERSDEPARTMENT OF FOOD SCIENCE
Montville, IFT 2004 45
DreadInvoluntary
Not dreadVoluntary
New, Unknown
Old, Known
What, me worry?
Causes of concern
______________STATE UNIVERSITY OF NEW JERSEY
RUTGERSDEPARTMENT OF FOOD SCIENCE
Montville, IFT 2004 46
DNA Research
Nuclear Power
Herbicides, DDT
Cycling Skiing
BST
Food Irradiation
Hair dyes
Jogging
MotorcyclesFirefighting
Crime
Smoking
Dread Not Dread
Unknown
Known
Anthrax
(you)
Anthrax
(me)
______________STATE UNIVERSITY OF NEW JERSEY
RUTGERSDEPARTMENT OF FOOD SCIENCE
Montville, IFT 2004 47
Loss of Life Expectancy – Bernard Cohen, J. Health Physics
THOUSANDS OF DAYS
______________STATE UNIVERSITY OF NEW JERSEY
RUTGERSDEPARTMENT OF FOOD SCIENCE
Montville, IFT 2004 48
Loss of Life Expectancy – Bernard Cohen, J. Health Physics
______________STATE UNIVERSITY OF NEW JERSEY
RUTGERSDEPARTMENT OF FOOD SCIENCE
Montville, IFT 2004 49
Homework #4
Identify either something that causes concern but shouldn’t or doesn’t cause concern, but should. Discuss why.
______________STATE UNIVERSITY OF NEW JERSEY
RUTGERSDEPARTMENT OF FOOD SCIENCE
Montville, IFT 2004 50
Take-home messages: Be number literate. Examine the underlying data. Understand the process. People overreact to dread-unknown risk,
while ignoring “every day” established risk. (We drive down the road while talking on our cell phone as we check our hair in the mirror and eat our egg McMuffin®.)