critical thinking in food safety thomas j. montville

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).




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)




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




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




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%.




Look for the grain of truth. Take it with a grain of salt.




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).




An important digression on “number literacy”

One can’t explain what one doesn’t understand.




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)




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?




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.




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




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.




False reasoning:

Furfural causes cancer

Bread contains furfural

Eating Bread Causes CancerEating Bread Causes Cancer




•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?




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.




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?”)






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






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?


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




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)


(µg/kg bw/d)

90th %


90th %


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




Intake (g/p/d)



All ages

200 250





No Juice Samples ExcludedSamples > 50 ug/kg Excluded REVISED AFTER FAC CONCERNS

Age Group

Ave. Juice Intake

(g/person/d)


(µg/kg bw/d)

90th %


90th %


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




Intake (g/p/d)



All ages

200 250



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!




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.)))




How to sort it out

2. Look for qualifiers and generalizations:might, can, possibly, potential, up to, etc




How to sort it out

3. Beware of Emotional Anecdotes




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.




How to sort it out

5. Be number literateIt’s mostly addition, subtraction multiplication, and division.




“The dosedose makes the poison.”

Dose = concentration x intake




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

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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




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.




What drives people crazy?

Concern = control x risk

(Risk = hazard x probability)




DreadInvoluntary

Not dreadVoluntary

New, Unknown

Old, Known

What, me worry?

Causes of concern




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)




Loss of Life Expectancy – Bernard Cohen, J. Health Physics

THOUSANDS OF DAYS




Loss of Life Expectancy – Bernard Cohen, J. Health Physics




Homework #4

Identify either something that causes concern but shouldn’t or doesn’t cause concern, but should. Discuss why.




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®.)

critical thinking in food safety thomas j. montville

Documents

natural food

food dollars

large food companies

food safety thomas

value of food industry

montville slide

google guess slide

incidence of cancer