What is Good Science, and How Does it Relate to Food Consumption?

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What is Good Science, and How Does it Relate to
Food Consumption?

• Keith R. Cooper, Ph.D.
• June 8, 2004

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The Land Grant System
Land Grant Institutions receive direct
federal, state and county appropriations to
extend the boundaries of traditional colleges and
universities to provide mission-oriented
science-based solutions to targeted problems and
deliver services to stakeholders.
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Cook CollegeProgram priority setting in the
future
Agriculture Food Systems
Food, Nutrition Health
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Human Community Health
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Environment Natural Resources
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What is Good Science?

• Results from well designed studies that are based
  on a testable hypothesis.
• Results that are reproducible by independent
  studies or laboratories.
• Results that are statistically defensible.

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What is Bad Science?

• When the outcome of the studies are designed in
  such a fashion as to give a predetermined
  outcome.
• When the study design is too small and apparent
  correlations are due too statistical error.
• When QA/QC protocols are compromised.

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How can the same data examined by different
groups give differing opinions as to risk?

• It may be dependent on the model used to
  extrapolate to obtain a risk number.
• It may be dependent on the assumptions used in
  the model for unknown parameters.
• It may be dependent on the endpoint
  (cancer-benign vs malignant or non-cancer
  endpoints) examined.

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Toxicology of Natural Anthropogenic Sources of
Contamination

• Food pathogens (Hepatitis, Vibrio, E. coli, Algal
  toxins and others) associated with waterborne
  contamination.
• Anthropogenic sources of metals, and persistent
  organic compounds.
• These pathogens and contaminants bioaccumulate
  into various tissues.

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Persistent Organic Compounds
Metals
Mercury
2,3,7,8-TCDD
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Mechanisms of 2,3,7,8-TCDD
Receptor binding
Activation
TCDD
TCDD
TCDD
AhR
AhR
ARNT
AhR
ARNT
cytoplasm
Gene products that regulate proliferation and
differentiation of cells
Transcription
Translation
mRNA
DNA
DRE
Nucleus
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Seawater control
Follicle
Maturing egg
N 10 oysters/day No significant
difference Equivalents based on ALP levels (mg/ml)
Growing egg
Developed follicle



Matured eggs
N 10 oysters/day significantly different
(ANOVA Plt0.05)
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2,3,7,8-TCDD 10 pg/gram
Follicle
Inhibited egg growth
Follicle

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N10 oyster significantly different (ANOVA Plt
0.05) Equivalents are based on ALP levels (mg/ml)
Growing egg
Abnormal egg growth
Inhibited egg growth and maturation

N10 oyster significantly different (ANOVA Plt
0.05)
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Integrated Eco-toxicological ModelingContaminatio
n of Aquatic and Terrestrial Systems (CATS)Traas
and Aldenberg 1992.
Contaminant Properties solubility Kow
Contaminant Properties
Toxicology
Environmental Chemistry
Toxicology
Environmental Chemistry
Sorption leaching partitioning
Metabolization assimilation excetion
Biotic Characteristics foodweb function
Abiotic Characteristics hydrology geochemistry
climate
Abiotic Conditions
Habitat factors nutrient cycling
Biota
Ecology
Ecology
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Uniqueness of Mercury Modeling

• The primary concern is methyl mercury which is
  produced in the environment. In other words, one
  must actually model four mercury species
  simultaneously. Collaboration with Dr. Buckley
  has allowed us to look at rates of metal
  speciation, which are essential in developing
  rate constants.

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Mercury Cycling in the Enviroment
Atmosphere
Hg II
Inert Hg
Hg II
Hg0
Green Boxes denote particulate bound While clear
denote dissolved
Aqueous Phase
Hg II
Hg0
MeHg
MeHg
Hg II
Inert Hg
Hg0
Hg II
MeHg
MeHg
Inert Hg
Benthos
Hg II
(Adapted From Bale (2000))
Burial to Deep Sediments and Re-entrainment
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Comparative Risk/Benefit Ratio

• US Dietary Guidelines potential health benefits
  from eating fish (omega-3 fatty acids reduce risk
  of sudden death from cardiac arrest and other
  ailments.)
• Breastfeeding has been clearly shown for infant
  and mother bonding, intervention on reducing
  dietary intake of animal fat for children.
  Reduction of intake in adult women will have
  little effect on stored body burdens.
• Cooking methods to reduce high fat containing
  portions.