Fish: The good and the bad Leslie E. Dorworth Illinois-Indiana Sea Grant College Program Purdue...
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Transcript of Fish: The good and the bad Leslie E. Dorworth Illinois-Indiana Sea Grant College Program Purdue...
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!
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
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
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
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.