Fish: The good and the bad Leslie E. Dorworth Illinois-Indiana Sea Grant College Program Purdue University Calumet Hammond, IN

Fish is Good Food! Source of protein and some minerals Source of Omega-3 fatty acids

Fish is Good Food! Easy to prepare Economical to catch locally Culturally important to many populations

U.S Fish Consumption Shrimp Canned Tuna Salmon Pollock Catfish Tilapia Crab Cod Clams Flatfish 4.2 lbs/person (Per Capita) H.M. Johnson & Assoc., 2005

What’s the Concern? Fish consumption is the major pathway for exposure to mercury and PCBs in the diet DeRosa, ATSDR FS_216-95/FS_ 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!

Overview Healthy Fats in Fish Mercury PCBs and TEQ Fish Advisories

Omega-3 Fatty Acids EPA – eicosapentaenoic acid – C20:5 n-3 DHA – docosahexaenoic acid – C22:6 n-3

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

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

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

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

Mercury

Mercury and Omega-3 Fatty Acids FishHg (ppm)Omega-3 FA (g/3oz) Shark Swordfish Tilefish King Mackerel Fresh/frozen Tuna Tuna, albacore Tuna, light

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

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

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) - Mercury ~6% of U.S. women have mercury levels in their blood that exceed the RfD (>5.8 µg/L) CDC, MMWR (43):

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

Mercury 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 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 ( mg/sandwich) Shim et. al., 2005

Mercury 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 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

PCBs & TEQ

Polychlorinated Biphenyls (PCBs)

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

Total PCBs in Coho Salmon Fillets (Lake Michigan) EPA/823-R , 1993

Maximum Total PCB in Sportfish Creek Chub White Sucker Rock Bass White Crappie Spotted Bass Green Sunfish Black Bullhead Channel Catfish Carp PCB (ppm)

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

Fish 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 of Childbearing Age and Children

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 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 Mercury FishHg (ppm)Omega-3 FA (g/3oz.) Canned Tuna (light) Shrimp<LOD=0.01 ppm0.27 Ollock Salmon Cod Catfish Clams<LOD=0.01 ppm0.24 Flounder/sole Crabs Scallops

For Advisory Information Current state and local advisories available at: – – 6fishadv.htm

Other Educational Materials Sensitive populations: – visory%2006.PDF (English) visory%2006.PDF – visory%2006%20Span.PDF (Spanish) visory%2006%20Span.PDF – visory%20Kosher%2006.PDF (Kosher) visory%20Kosher%2006.PDF

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

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

Questions?