Animal Aid

The Fishing Industry : Health

Fish contain unhealthy saturated fats

  • 30% of the fat in fish can be saturated. (1) This is a risk factor for heart disease.
  • There are two types of polyunsaturated fat that our bodies need. These are in the form of essential fatty acids (EFAs) - omega-6 and omega-3.
  • Necessary polyunsaturated fats found in oily fish, such as herring, mackerel, fresh salmon, fresh tuna, sardines and trout can also be found in foods such as green leafy vegetables, pulses, seeds and nuts.
  • Most diets are well supplied with omega-6 fats, as these are found in sunflower, corn and vegetable oils.
  • Oily fish (as popularly assumed) is not the only source of omega-3 fats. Seeds, nuts, beans and their oils - especially linseeds (flax), soya oil, rapeseed oil and walnuts - are all very rich in the essential omega-3 fats. (2) Green vegetables are also a source of omega-3 fats in the diet. (3)
  • Professor Tom Sanders, Head of the Research Division of Nutritional Sciences, King's College London:

    "Vegans and vegetarians can meet their requirements for omega-3 fatty acids by consuming foods that contain alpha-linolenic acid. Rich sources of alpha- linolenic acid include soybeans including soya milk and tofu, walnuts, rapeseed oil, flaxseed and dark green vegetables such as spinach. Fish oils contain long-chain omega-3 fatty acids in particular eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). EPA and DHA can be made in the body from alpha-linolenic acid. DHA is needed as structural component of the brain. Relatively high intakes of long-chain omega-3 fatty acids have some pharmacological (drug like) properties that may reduce the risk of blood clotting and reduce inflammation.

    We have studied omega-3 fatty acid levels in vegans for over 30 years and shown that vegans can make DHA from alpha-linolenic acid. We have followed vegan children from pregnancy to adulthood and shown that they develop quite normally despite the lack of long-chain omega-3 fatty acids in the diet. Breast milk plays a particularlyimportant role in providing the infant with DHA needed for brain development and most of the children we studied were breastfed for at least the first year of life. Breastmilk substitutes may need to be fortified with DHA and this can now be done with DHA of algal origin."

Omega-3 fats from plants are healthier than those from oily fish

  • Plants, being at the bottom of the food chain, are much less likely than fish to be contaminated with pollutants.
  • Plant sources of omega-3 fats additionally contain vitamin E, which is vital in stopping the omega-3 fats going rancid.
  • Fish are a poor source of protective vitamin E. The 'fishy' smell at fish counters indicates that the fish is already rotting!

Plant-based diets will protect your heart without any need for fish oils

  • There is now a considerablebody of scientific evidence to show that people who are at low risk of heart disease are those with a healthy lifestyle, who eat a diet low in saturated fat and rich in pulses, beans, wholegrains, fruits and vegetables - along with plant-derived oils from seeds and nuts.
  • A study found that heart attack victims who ate a Mediterranean-type diet (high in fresh fruit and vegetables and low in meat) using plant oils instead of fish, reduced their risk of having a fatal second heart attack by 70%. (4)
  • Studies have shown that flaxseed oil (linolenic acid) can lead to a 38% decrease in C-reactive protein in the blood - high levels of which are associated with heart disease. (4) This strongly suggests a unique role for flaxseed oil in reducing C-reactive protein - a benefit not afforded by fish oils. (5)

Oily fish may be contaminated with residues of chemicals, some of which have been described by experts as the most toxic known to man

  • Our seas and rivers are increasingly contaminated with pollutants from industrial and agricultural wastes. Fish are literally swimming in our filth.
  • The fat in fish (as well as in meat and dairy) acts like a sponge, readily soaking up any toxins in the environment, such as PCBs (polychlorinated biphenyls) and dioxins, which have been linked to cancer and birth defects.
  • The Consumers' Association has warned that high levels of dioxins and PCBs could be putting millions of people at risk. (6)
  • A survey of branded fish oil supplements carried out by the Food Standards Agency (FSA) in 2002 found that 12 out of 33 samples contained concentrations of dioxins that exceeded the European Commission's limit for fish. (7)
  • Fears over possible toxin contamination in fish have led the Government's Food Standards Agency (FSA) - for the first time ever - to advise on maximum levels of fish consumption.
  • As from June 2004, the FSA advise that girls under 16, women who might have a child one day and women who are pregnant or breastfeeding, should have no more than two portions of oily fish a week (one portion is 140g).

Non-oily fish may be contaminated with toxins such as mercury

  • Eating fish is the main source of mercury in the diet. (9)
  • Mercury is a poison that can affect the central nervous system, kidneys and heart. It can even harm the developing nervous system of an unborn child and is possibly a cause of infertility. (10)
  • If pregnant women are exposed to sufficiently high levels, mercury can cause deformities in babies. (18)
  • Researchers have found that a high intake of mercury from eating non-fatty fish is associated with an increased risk of mortality from coronary heart disease. (11)
  • Due to possible mercury contamination, pregnant women and those who may become pregnant, are advised by the FSA to limit the amount of tinned tuna that they eat. (8)
  • Vegetarians are much less likely to be exposed to mercury - in 2000, a study of vegetarian diets could detect no mercury in the foods eaten. (12)

Farmed salmon is particularly unhealthy

  • Most salmon eaten today comes from factory farmed fish.
  • Farmed salmon have been shown to have higher levels of PCBs and pesticides than wild salmon. The fish oil and fishmeal fed to salmon is likely to be contaminated - hence the higher levels of toxins in factory farmed salmon. (13)
  • Research reported in the January 2004 edition of Sciencemagazine found that levels of cancer-causing toxins in Scottish farmed salmon are so high that consumers are warned not to eat more than one portion (140g) every two months. (14)
  • Wild salmon get their pink hue from natural food sources such as algae and small crustaceans. Farmed fish are fed the pigment Canthaxanthin, which has been linked to eye defects in children and is banned in the US because it is believed to be carcinogenic. (15)&(16)
  • DDT - a nerve poison that was used extensively as an agricultural insecticide and has been banned in the UK since 1986 - has been found in farmed fish, as it persists in the environment and bioaccumulates in animals. There is also widespread concern that Dichlorvos - used to kill sea lice - has been linked to testicular cancer. (17)
  • Traces of radioactive waste from Sellafield have been found in farmed salmon on supermarket shelves. (17)
  • Fish kept in confined areas become susceptible to diseases, which are routinely treated with antibiotics. This causes the disease organisms to mutate and become drug-resistant superbugs. When humans are exposed to those same bugs, the antibiotics they are given are ineffective. Even wild fish caught near fish farms contain antibiotics in their flesh. (17)


  1. FSA. 2002. McCance and Widdowson's. The Composition of Foods. HMSO, London.
  2. Buttriss, J. 1999. n-3 Fatty Acids And Health.(BNF)
  3. Pereira, C. et al. 2001. The Alpha-Linolenic Acid Content of Green Vegetables Commonly Available in Australia. Int. J. Vitam. Nutr. Res.71(4), 223-228.
  4. De Lorgeril, M. et al. 1994. Mediterranean Alpha-Linolenic Acid-Rich Diet in Secondary Prevention of Coronary Heart Disease. The Lancet. 343,1454-1459.
  5. Walsh, S. 2003. Plant Based Nutrition and Health.Vegan Society.
  6. Consumers' Association. 2002. Fish - What's The Catch? Which Magazine. October.
  7. FSA. 2002. Dioxins and Dioxin-Like PCBs in Fish Oil Supplements.
  8. FSA News No.40. July/August 2004. Fish Advice Stresses Health Benefits.
  9. FSA (40/03) July, 2003. Mercury in Imported Fish and Shellfish, UK farmed fish and their Products.
  10. Choy, C.M.Y. et al.2002. Infertility, Blood Mercury Concentrations and Dietary Seafood Consumption: A Case-Control Study.BJOG: An. Intl. J. Obstetrics & Gynaecology. 109, 1121-1125.
  11. Salonen, J.T. et al.1995. Intake of Mercury from Fish, Lipid Peroxidation and the Risk of Myocardial Infarction and Coronary, Cardiovascular and Any Death in Eastern Finnish Men.Circulation. 91, 645-655.
  12. MAFF. 2000. Duplicate Diet Study of Vegetarians - Dietary Exposures to 12 metals and Other Elements. 2000-193
  13. Easton, M.D.L. et al 2002. Preliminary Examination of Contaminant Loadings in Farmed Salmon, Wild Salmon and Commercial Salmon Feed.Chemosphere. 46, 1053-1074.
  14. Brown, P. and Scott, K. Jan 2004. Scots Farmed Salmon is Cancer Risk, Says Study. The Guardian.
  15. Dec. 2002. Pink Poison. Daily Mail.
  16. The Salmon Farm Monitor.
  17. Shooter, A. March 2005. What are we eating? Daily Mail.
  18. Nicholson-Lord, D. 2004. Poisoning Ourselves. August 28th 44-45.

Click here for part 4 of The Fishing Industry.

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