Safety of seafood. by Øyvind Lie Director. National Institute of Nutrition and Seafood Research

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1 Safety of seafood by Øyvind Lie Director National Institute of Nutrition and Seafood Research NIFES conduct research and develop analytical methods within the health aspects of eating seafood in a whole food chain perspective which includes research within aquaculture nutrition, seafood as human nutrition, and documentation and surveillance of feed and seafood.

2 Future focus on seafood safety will include Distinction of metals chemical forms in risk assessment Dioxins and dioxin-like PCBs Flame retardants Balanced risk assessment

3 Pollution is a global problem Which substances? Do they influence food safety and our health? Research and documentation

4 Faroe Islands Grandjean et al & 2003 Seychelles Davidson et al Identified negative effect in children Substantial part of mothers diet: sea mammals High in organic mercury? (methylmercury) Similar exposure detected in mothers Measure: inorganic + organic mercury No adverse effect from chronic exposure of low levels Mercury exposure: mostly from ocean fish Low in organic mercury?

5 Mercury levels in Norwegian seafood mg/kg wet weight 0,5 0 0,03 0,03 0,05 0,01 0,04 0,04 Codex 0.5mg/kg wet weight Cod Mackerel Saithe Haddock Herring Salmon

6 Methylmercury Different toxicity of mercury from different seafood, because the chemical form of mercury is different EU and CODEX maximum limits are based on total mercury = organic mercury + inorganic mercury (less toxic) NIFES: Proportion of methylmercury varies from 43-94% in different seafood samples Research into chemical forms important for human health is essential for appropriate legislation

7 Arsenic Has become a problem for aquaculture due to lack of knowledge about arsenic in the marine environment HO O OH As As H As OH 3 C OH H As 3 C OH HO HO OH HO H 3 C As(V) As(III) MMA DMA O CH 3 CH 3 H As 3 C H C As + 3 H C As + CH 3 CH 3 CH 2 OH 3 C H 3 C H 3 C H 3 C H2 TMAO TMAs AsC O O CH O 3 H C As + - As As 3 COO H C COOH CH H C 2 OH 3 C 3 C C H 3 C H2 H C H2 H 3 C H2 3 AsB DMAA DMAE O AB2 H C As CH 2 OH 3 C R O H 3 C H2 O H As R 3 C HO O O TMAP H O O P 3 C O OH HO OH OH OH Dimethylarsinoylriboside As-sugar 2 O O HCOOH 3 C + (7) As H 3 C CH 3 O OSO 3 H OH Dimethyl As-sugar 4 HO O O R N H (8) OH Trimethylarsonioriboside COOH R = 1,2,3,4,5 More than 25 different chemical forms of arsenic have been found in the marine environment Different chemical forms have different toxicity OH HO O O P O OH OH OH Dimethyl As-sugar 1 Dimethyl As-sugar 2 SO 3 H OH OH Dimethyl As-sugar 3 Dimethyl As-sugar 4 O OMe H COOH (5) (6) (7) O OSO 3 H O N H (8) OH COOH

8 Arsenic LD 50 -values(mg/kg) As III AsV Terrestrial animals Inorganic arsenic Toxic Arsenic Chemical form 50% retained Organic arsenic Arsenobetaine 50% out LD 50 -values(mg/kg) AsB > % out after 6-24hrs Not toxic

9 Arsenic Arsenic in seafood is largely in the form of arsenobetain which is not dangerous (SCAN report) No maximum limit in food Maximum limit in feed recently adjusted from 4 to 6mg/kg Risk assessment ongoing in EFSA

10 Focus recently: Brominated Flame Retardants What are they? Chemicals restricting the spread of fire Added to many consumer products Toxic in animal studies e.g. disruption of brain development

11 Food safety: New compounds continually addressed A C B D Poly- Brominated Diphenyl Ether 4 major classes Research mainly focused on 1 - PBDE (fig. B) There are 209 different chemical forms of PBDE Routes of exposure include food, inhalation and skin contact foods Build up in the food chain NIFES analyse different chemical forms of PBDEs since 2003 (accredited) Working to implement analysis of two other classes (TBBPA and HBCD)

12 Levels of PBDEs in human breast milk are increasing while levels of PCBs and dioxins are decreasing Where bans exist, as in Sweden, PBDE levels are decreasing Hooper & She (2003); Norèn & Mieronytè (1998)

13 Farmed Feed 0.6 to 7.9 ng/g Wild PBDE levels 1.0 to 4.5 ng/g 0.5 to 1.1 ng/g Effect in humans? Hotspots: Lake Michigan in USA 80ng/g Herring 1 to 3.5 ng/g Only a few species analysed Great variations within species Variations between locations Complexity

14 Surveillance Challenge Adequate surveillance number of samples, species, location, frequency Compounds current and new Ensure adequate documentation to assess food safety and comply with legislation

15 Sustainable expansion of aquaculture industry has led to increased concerns about the future availability of marine fish oils for aquafeeds and other purposes. Global supply of marine fish oils remain relatively constant. How does alternative feed ingredients affect fish health and human health? Fish health Quality Human health Feed Researching Alternatives to Fish Oils for Aquaculture RAFOA and others

16 Researching Alternatives to Fish Oils for Aquaculture - RAFOA Plant oils Fish health Quality Human health Feed Sustainability Affecting gene expression

17 Expression of the delta-5-desaturase gene in liver is increased in livers from salmon fed 100% VO: 3000 Normalised expression Sea water transfer 3.6 fold P= fold P= fold P= % FO 100% VO Fish weight Zheng, X., Torstensen, B. E., Tocher, D.R., Dick, J.R., Henderson, R.J. and Bell, J.G., Manuscript.

18 Researching Alternatives to Fish Oils for Aquaculture - RAFOA Plant oils Fish health Quality Human health Feed Gene expression Nutrients + Sustainability

19 Fatty acid composition in the feed is reflected in the fillet AFeed Fillet B 40 % FA 30 Sum n-3 % FA Sum n % F 50/50% F/R 100%R 0 100% F 50/50% F/R 100%R 10 8 Ratio n-3/n Ratio n-3/n % F 50/50% F/R 100%R 0 100% F 50/50% F/R 100%R Seierstad et al. submitted 100% fish oil 50% fish oil 50% rapeseed oil 100% rapessed oil

20 Researching Alternatives to Fish Oils for Aquaculture - RAFOA Plant oils Fish health Quality Human health Feed Sustainability Gene expression Nutrients Contaminants + -

21 Reduce levels of dioxins and dioxin-like PCBs in fillets by using vegetable oils in feed * * *

22 Transfer of persistent organic pollution from feed to fish Dioxin-like-PCBs accumulate nearly 2 times faster from feed to fish than dioxins New EU legislation by the end of 2004 for dioxins + dioxin like PCBs in feed and (sea) food Feed dioxin:pcb 1:1 Fish dioxin:pcb 1:2 Dioxin 43% Dioxin-like-PCB 72%

23 Reducing levels of dioxins in fish fillet: 1) Select marine feed materials with naturally low levels of dioxins 2) Use non-marine feed materials with naturally low levels of dioxins 3) Remove undesirables from marine feed materials Low dioxins Important knowledge for legislative bodies

24 Researching Alternatives to Fish Oils for Aquaculture - RAFOA Plant oils Fish health Quality Human health Feed Sustainability Gene expression Nutrients Contaminants Look Taste + -

25 Fat in feed used 100% Fish oil Sensory test Corresponding fillets Tasted by test panel 75% Fish oil 25% Rapeseed oil 50% Fish oil 50% Rapeseed oil Very similar in flavour odour texture 50% Fish oil 50% Olive oil 100% Rapeseed oil Different from rest

26 Researching Alternatives to Fish Oils for Aquaculture - RAFOA Plant oils Fish health Quality Human health Feed Sustainability Gene expression Nutrients + Is choice of feed resources for fish Contaminants - farming important Look for human health? Taste

27 Fish fillet Heart patients Effect Feed with different omega-3 levels give tailored fish High omega-3 Medium omega-3? Low omega-3 Collaboration: NIFES (coordinator), Nutreco, School of Veterinary Medicine og Ullevål Universitety Hospital

28 Fish feed composition can influence human health Salmon Human AFeed Fillet B Serum C 40 % FA Sum n-3 % FA Sum n-3 FA mg/l Sum n % F 50/50% F/R 100%R 0 100% F 50/50% F/R 100%R 0 100% F 50/50% F/R 100%R 10 8 Ratio n-3/n Ratio n-3/n Ratio n-3/n % F 50/50% F/R 100%R % F 50/50% F/R 100%R % F 50/50% F/R 100%R Seierstad et al. Eur. J. Clin. Invest. Inn press 100% fish oil 50% fish oil 50% rapeseed oil 100% rapeseed oil

29 Conclusions The results show that the fatty acid composition of farmed Atlantic salmon greatly influence serum lipid levels in patients with Coronary Heart Disease. All patients had positive health effects from eating salmon, even the ones eating fish fed 100% rapeseed oil. The salmon with extremely high levels of omega-3, gave the best health effect for heart disease patients. Seierstad et al. Eur. J. Clin. Invest. Inn press

30 Challenge: scientific documentation in the whole food chain Feed ingredients Fish health Quality Human health Feed + - Sustainability Using plant oils remove some problems, like dioxins. But will other components become a problem? Use of GMO feed ingredients Pesticides (dieldrin, toxafen, +++)

31 Seafood is a unique source of nutrients Farmed fish Feed _ + Omega-3 Vitamin D Iodine Selenium _ + Wild fish (Seafood) Marine rawmaterial and biproducts _ + Seafood consumption and health But: Presence of undesirable substances

32 Does the positive aspects of eating seafood outweigh the risk? + Vit. A Omega-3 Iodine Dioxins Methylmercury Brominated Flameretardant _ Balanced effect assessment on human health

33 Considering mercury contamination in seafood, it is still more healthy to eat such seafood than not eating fish at all % risk for developing 1st myocardial infarction % reduction 67 % reduction low high high mercury (low) Fish intake Rissanen et al. Circulation 2000 Nov 28;102(22):2677-9

34 Balanced health risk assessment 24th June 2004: The Food Standards Agency (UK) issued for the first time maximum levels at which health benefits of eating oily fish clearly outweigh the possible risk from dioxins

35 Eating oily fish FSA advice Considered positive health effects: Cut the risk of heart diseases and positive influence on pregnancy outcome Considered negative health effects related to the presence of dioxins, dioxin-like PCBs, brominated flame retardants, mercury, cadmium, lead Used Tolerable Weekly Intake limits to protect the most sensitive consumer (foetus) Advice: Everyone should eat fish twice a week, with one meal of fatty fish Pregnant women should be careful with some species due to high content of mercury (marlin, shark and swordfish). Others can eat 1-4 meals of fatty fish per week So far: no established method for balanced risk assessment in seafood. More research is needed

36 Summary Future challenges - seafood safety More knowledge about persistent organic pollutants Research into chemical forms of metals related to health Interaction between positive and negative components in seafood Balanced risk assessment

37 Acknowledgement of picture used Brominated flame retardants:u.s. EPA National Forum on Contaminants in Fish, by Dr. Tom A. McDonald OEHHA, California EPA Others: