Fish: The good and the badFish: The good and the bad

Leslie E. DorworthIllinois-Indiana Sea Grant College ProgramPurdue University CalumetHammond, IN

Fish is Good Food!Fish is Good Food!

Source of protein and some minerals

Source of Omega-3 fatty acids

Fish is Good Food!Fish is Good Food!

Easy to prepareEconomical to

catch locallyCulturally

important to many populations

U.S Fish Consumption - 2004U.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

What’s the Concern?What’s 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.html

Bioaccumulation/magnification:

1. Pollutants get into the sediment or water from man-made or natural processes

2. Plants and small organisms absorb/ingest the pollutants, including juvenile fish.

3. Large fish eat smaller fish.

4. Top predators (man, eagles, raccoons, etc…) eat the big fish.

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

OverviewOverview

Healthy Fats in FishMercuryPCBs and TEQFish Advisories

Omega-3 Fatty AcidsOmega-3 Fatty Acids

EPA – eicosapentaenoic acid – C20:5 n-3

DHA – docosahexaenoic acid – C22:6 n-3

Healthy Fats in FishHealthy Fats in Fish

DHA – important for brain/eye developmentNAS, 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

Possible MechanismsPossible 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

Dietary RecommendationsDietary 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

What % of the recommended levels do you get What % of the recommended levels do you get if you consume 8 oz/week?if you consume 8 oz/week?

497

267

41 31

140

74

12 8

7037

6 40

100

200

300

400

500

600

AtlanticSalmon

Rainbow Trout ChannelCatfish

Canned Lt.Tuna

Per

cen

tag

e

NAS

DG

AHA

MercuryMercury

Mercury and Omega-3 Fatty AcidsMercury and Omega-3 Fatty AcidsFish Hg (ppm) Omega-3 FA

(g/3oz)

Shark 0.99 0.90

Swordfish 0.97 0.70

Tilefish 1.45 0.80

King Mackerel 0.73 0.34

Fresh/frozen Tuna

0.38 0.24-1.28

Tuna, albacore 0.32 0.7

Tuna, light 0.12 0.26

Mercury Toxicity in AdultsMercury Toxicity in Adults

Patients living in San FranciscoHigh-end consumers of higher Hg fishSymptoms including fatigue, headache,

decreased memory, decreased concentration, muscle and joint pain

Symptoms gone after diet changes

MethylmercuryMethylmercury

Crosses placenta and into breast milkClearance from body ~ 1 yearFDA Action Level (fish tissue) = 1 ppmCanadian Limit (fish tissue) = 0.5 ppm

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

NHANES (1999–2002) - MercuryNHANES (1999–2002) - Mercury

~6% of U.S. women have mercury levels in their blood that exceed the RfD (>5.8 µg/L)

CDC, MMWR. 2004. 53(43):1018-1029

EPA ProjectionEPA Projection

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

Mahaffey, EPA 2004

Mercury in Fish SandwichesMercury in Fish Sandwiches

Fish in sandwiches from 6 restaurant chains– Dairy Queen, McDonald’s Burger King, White Castle,

Long John Silver’s and Subway 5 sandwiches from 4 stores for each chain Range 5-132 ppb hg – well below FDA Action

Level for Hg of 1000 ppb…can exceed EPA’s RfD by 1.4x for 2 products

Low in EPA/DHA (92-620 mg/sandwich)Shim et. al., 2005

Mercury in Canned FishMercury in Canned Fish

Canned tuna (n=240), salmon (n=16), and mackerel (n=16)

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

Canned Tuna and MercuryCanned Tuna and Mercury

Main source of dietary mercury exposureServed 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

PCBs & TEQPCBs & TEQ

Polychlorinated Biphenyls Polychlorinated Biphenyls (PCBs)(PCBs)

209 CongenersAroclors® include ~ 60 congeners

Aroclor 12 6812 represents 12 carbons

68 represents the % chlorine

PCBsPCBs

~ 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

Total PCBs in Coho Salmon Total PCBs in Coho Salmon Fillets (Lake Michigan)Fillets (Lake Michigan)

00.20.40.60.8

11.21.41.61.8

2

pp

m

1978

1981

1983

1985

1987

1989

1991

EPA/823-R-93-003, 1993EPA/823-R-93-003, 1993

Maximum Total PCB in SportfishMaximum Total PCB in Sportfish

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

PCB (ppm)426355300235220110644135

Sources of PCB (TEQ) in U.S. DietSources of PCB (TEQ) in U.S. Diet

Beef (78 g/d)

MarineFish/Shellfish

Milk (27 g/d)

Poultry (82 g/d)

Pork (58 g/d)

13.6% Farmed Salmon (2.5 g/d)13.6% Farmed Salmon (2.5 g/d) 8.4% Other Fish (16 g/d) 8.4% Other Fish (16 g/d) NAS, 2003NAS, 2003

Fish AdvisoriesFish Advisories

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(bioaccumulation)

-Older fish

-Source?

FDA & EPA Advisory for Women FDA & EPA Advisory for Women of Childbearing Age and Childrenof Childbearing Age and Children

Advice For Women Who Are Pregnant, Or Who Advice For Women Who Are Pregnant, Or Who Might Become Pregnant, and Nursing Mothers Might Become Pregnant, and Nursing Mothers About Avoiding Harm To Your Baby Or Young About Avoiding Harm To Your Baby Or Young

Child From Mercury In FishChild 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 fish…check local advisories.

Eat up to 6 oz. of Albacore/white tuna per week, and on other fish in the same week

FDA/EPA 2004

Choose Fish Low in MercuryChoose Fish Low in Mercurywww.americanheart.orgwww.americanheart.org

Fish Hg (ppm) Omega-3 FA (g/3oz.)

Canned Tuna (light) 0.12 0.26

Shrimp <LOD=0.01 ppm 0.27

Ollock 0.06 0.46

Salmon 0.01 0.68-1.83

Cod 0.11 0.13-0.24

Catfish 0.05 0.15-0.20

Clams <LOD=0.01 ppm 0.24

Flounder/sole 0.05 0.43

Crabs 0.06 0.34-0.40

Scallops 0.05 0.17

For Advisory InformationFor Advisory Information

Current state and local advisories available at:– http://fn.cfs.purdue.edu/fish4health/– http://www.idph.state.il.us/public/

press06/2.2.06fishadv.htm

Other Educational MaterialsOther Educational Materials

Sensitive populations:– http://fn.cfs.purdue.edu/anglingindiana/FishAd

visory%2006.PDF (English)

– http://fn.cfs.purdue.edu/anglingindiana/FishAdvisory%2006%20Span.PDF (Spanish)

– http://fn.cfs.purdue.edu/anglingindiana/FishAdvisory%20Kosher%2006.PDF (Kosher)

Ways To Educate OthersWays 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

I would like to thank Dr. Charles I would like to thank Dr. Charles Santerre of Purdue University for Santerre of Purdue University for

providing the bulk of the slides for this providing the bulk of the slides for this presentation.presentation.

Questions?Questions?