Fish: The good and the bad

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Fish The good and the bad

• Leslie E. Dorworth
• Illinois-Indiana Sea Grant College Program
• Purdue University Calumet
• Hammond, IN

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Fish is Good Food!

• Source of protein and some minerals
• Source of Omega-3 fatty acids

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Fish is Good Food!

• Easy to prepare
• Economical to catch locally
• Culturally important to many populations

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U.S Fish Consumption - 2004

• Shrimp
• Canned Tuna
• Salmon
• Pollock
• Catfish
• Tilapia
• Crab
• Cod
• Clams
• Flatfish

• 4.2 lbs/person
• 3.3
• 2.1
• 1.3
• 1.1
• 0.7
• 0.6
• 0.6
• 0.5
• 0.3
• 16.6 (Per Capita)
• H.M. Johnson Assoc., 2005

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Whats the Concern?

• Fish consumption is the major pathway for
  exposure to mercury and PCBs in the diet
• DeRosa, ATSDR 1998
• http//water.usgs.gov/wid/FS_216-95/FS_216-95.htm
  l

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Bioaccumulation/magnification

• Pollutants get into the sediment or water from
  man-made or natural processes
• Plants and small organisms absorb/ingest the
  pollutants, including juvenile fish.
• Large fish eat smaller fish.
• Top predators (man, eagles, raccoons, etc) eat
  the big fish.

Some pollutants can be found at much higher
levels in fish compared with sediment!
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Overview

• Healthy Fats in Fish
• Mercury
• PCBs and TEQ
• Fish Advisories

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Omega-3 Fatty Acids

• EPA eicosapentaenoic acid C205 n-3
• DHA docosahexaenoic acid C226 n-3

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Healthy Fats in Fish

• DHA important for brain/eye development
• NAS, 2002
• An estimated 250,000 Americans die each year from
  sudden cardiac death
• AHA
• consumption of long chain omega-3 fatty acids
  as found in fatty fish may reduce the risk of
  coronary heart disease
• ISSFAL, 1994

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Possible Mechanisms

• Preventing arrhythmias
• Decreasing platelet aggregation
• Decreasing plasma triglycerides
• Moderately decreasing blood pressure
• Reducing atherosclerosis
• Small increase in HDL cholesterol
• Modulating endothelial function
• Decreasing pro-inflammatory eicosanoids
• NAS, 2002

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Dietary Recommendations

• National Academy of Sciences (NAS) 2002
• EPA DHA 0.14 g/day for nursing and or
  pregnant women
• Dietary Guidelines Advisory Committee Report
  2004
• 8 oz fish/week
• American Heart Association (AHA)
• 2 servings (2-3 oz per serving) of fatty
  fish/week
• EPA DHA 1 g/d for heart disease patients

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What of the recommended levels do you get if
you consume 8 oz/week?
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Mercury
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Mercury and Omega-3 Fatty Acids
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Mercury Toxicity in Adults

• Patients living in San Francisco
• High-end consumers of higher Hg fish
• Symptoms including fatigue, headache, decreased
  memory, decreased concentration, muscle and joint
  pain
• Symptoms gone after diet changes

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Methylmercury

• Crosses placenta and into breast milk
• Clearance from body 1 year
• FDA Action Level (fish tissue) 1 ppm
• Canadian Limit (fish tissue) 0.5 ppm

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Why focus on women of child-bearing age?
Toxins can cross the placenta and are found in
breast milk Fetal exposure can effect behavioral
, neurological and cognitive function in infants
and children Many of the most pronounced effects
occur in the first trimester and chemicals like
PCBs have a long half-life in the blood
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NHANES (19992002) - Mercury

• 6 of U.S. women have mercury levels in their
  blood that exceed the RfD (gt5.8 µg/L)
• CDC, MMWR. 2004. 53(43)1018-1029

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EPA Projection

• 15 (630,000 babies of the 4 million born
  annually) may be exposed to excessive mercury
  when in the womb
• Mahaffey, EPA 2004

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Mercury in Fish Sandwiches

• Fish in sandwiches from 6 restaurant chains
• Dairy Queen, McDonalds Burger King, White
  Castle, Long John Silvers and Subway
• 5 sandwiches from 4 stores for each chain
• Range 5-132 ppb hg well below FDA Action Level
  for Hg of 1000 ppbcan exceed EPAs RfD by 1.4x
  for 2 products
• Low in EPA/DHA (92-620 mg/sandwich)
• Shim et. al., 2005

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Mercury in Canned Fish

• Canned tuna (n240), salmon (n16), and mackerel
  (n16)
• All samples were well below FDA Action Level for
  Hg of 1,000 ppb
• Tuna (all types) 188 ppb salmon 45 ppb
  mackerel 55 ppb
• Chunk light tuna in water 54 ppb but also lower
  in EPA/DHA
• Shim et. al., 2004

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Canned Tuna and Mercury

• Main source of dietary mercury exposure
• Served in school lunch programs and provided by
  WIC clinics to lactating women
• Consumer reports recommends women who are
  pregnant or nursing to not consume any canned
  tuna

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PCBs TEQ
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Polychlorinated Biphenyls (PCBs)

• 209 Congeners
• Aroclors include 60 congeners
• Aroclor 12 68
• 12 represents 12 carbons
• 68 represents the chlorine

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PCBs

• 6 years to clear from the body
• Passes throough the placenta and into milk
• U.S. and Canadian Limit (fish tissue) 2 ppm
  (expected to increase cancer risk by 1 in
  100,000)
• Infants exposed at high levels
• Have altered postnatal development, lower birth
  weight, smaller head circumference, poorer
  short-term memory
• Safe 1992 EPA/823-R-93, 1993

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Total PCBs in Coho Salmon Fillets (Lake Michigan)
EPA/823-R-93-003, 1993
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Maximum Total PCB in Sportfish

• Creek Chub
• White Sucker
• Rock Bass
• White Crappie
• Spotted Bass
• Green Sunfish
• Black Bullhead
• Channel Catfish
• Carp

• PCB (ppm)
• 426
• 355
• 300
• 235
• 220
• 110
• 64
• 41
• 35

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Sources of PCB (TEQ) in U.S. Diet
13.6 Farmed Salmon (2.5 g/d) 8.4 Other Fish
(16 g/d)
NAS, 2003
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Fish Advisories
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Fishy Characteristics
How can you tell if the fish you caught has a lot
of mercury or other contaminants? Does it smell,
look, act or taste different?
General Guidelines -Larger fish vs. smaller
fish -Fish that are top predators (bioaccumulatio
n) -Older fish -Source?
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FDA EPA Advisory for Women of Childbearing Age
and Children
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Advice For Women Who Are Pregnant, Or Who Might
Become Pregnant, and Nursing Mothers About
Avoiding Harm To Your Baby Or Young Child From
Mercury In Fish

• Do not eat Shark, Swordfish, King Mackerel,
  Tilefish
• Eat up to 12 oz. (2 average meals) of a variety
  of fish and shellfish that are lower in mercury.
• For recreationally-caught fishcheck local
  advisories.
• Eat up to 6 oz. of Albacore/white tuna per week,
  and on other fish in the same week
• FDA/EPA 2004

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Choose Fish Low in Mercurywww.americanheart.org
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For Advisory Information

• Current state and local advisories available at
• http//fn.cfs.purdue.edu/fish4health/
• http//www.idph.state.il.us/public/press06/2.2.06f
  ishadv.htm

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Other Educational Materials

• Sensitive populations
• http//fn.cfs.purdue.edu/anglingindiana/FishAdviso
  ry2006.PDF (English)
• http//fn.cfs.purdue.edu/anglingindiana/FishAdviso
  ry200620Span.PDF (Spanish)
• http//fn.cfs.purdue.edu/anglingindiana/FishAdviso
  ry20Kosher2006.PDF (Kosher)

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Ways To Educate Others

• Local stakeholder involvement
• Translation of health education materials
• Signage
• Mass media
• Outreach at fairs and festivals
• One-on-one counseling
• Small grants for community programs
• FSNEP Fish Connection
• Collaboration with WIC

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I would like to thank Dr. Charles Santerre of
Purdue University for providing the bulk of the
slides for this presentation.
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Questions?