Farmed Fish Human Intervention Study
Condition: Cardiovascular Disease
MeSH terms: Cardiovascular Diseases
Study type: Interventional

Summary: 
      Consumption of fish can help to prevent cardiovascular disease. The precise way in which fish
      is beneficial is not fully understood. This is important to find out as fish consists of a
      complex mixture of fatty acids and micronutrients such as vitamin D and selenium that could
      individually, or collectively, be responsible for the beneficial effects.

      Fish farming in Scotland is playing an increasingly important role in the provision of fish
      for human consumption. But issues with sustainability of raw materials are requiring fish
      farming to reformulate fish diets, which may affect the levels of beneficial omega-3 fatty
      acids and other components in fish.

      In this study we will be comparing the long-term health effects of eating two portions a week
      of Scottish salmon raised on a traditional fish diet versus eating two portions a week of
      Scottish salmon raised on a more sustainable fish diet. In addition, we will be looking at
      differences in health outcomes when eating two portions a week of either Scottish salmon,
      compared with eating no fish at all.
    

Detailed description: 
      Aquaculture has the potential to take the pressure off wild fish stocks whilst meeting the
      dietary needs of the population for omega 3 fatty acids and other key nutrients such as
      vitamin D. The industry is working hard to improve sustainability - between 1995 and 2006 it
      has been estimated that the input to output ratios for salmon improved from 7.5 to 4.9 and
      trout from 6.0 to 3.4- but there is a need to do more. Reductions in fish stocks and catch
      quotas, in addition to sustainability considerations, mean that farmed fish may have to be
      raised on vegetable oils for example but this may reduce the omega 3 content and may affect
      the content of other nutrients. Fish are an important component of the diet and there is a
      need to understand the effect of pressures from sustainability on methods of production and
      the health giving properties of fish. We have now been commissioned by the Scottish
      Government's Rural and Environment Science and Analytical Services Division (RESAS) to do
      research on the health effects of Scottish farmed fish fed different feeding regimes in the
      Scottish population, and assess how differential effects in measured health outcomes could be
      related to fish composition.

      Consumption of fish or omega-3- fatty acids from fish reduces coronary heart disease
      mortality, the leading cause of death in developed nations. The precise way in which fish
      provides benefit is not fully understood. This is important as fish and fish oils consist of
      a complex mixture of fatty acids and micronutrients that could individually, or collectively,
      be responsible for the beneficial effects. Aquaculture in Scotland is playing an increasingly
      important role in the provision of fish for human consumption, but issues with sustainability
      are requiring aquaculture to replace traditional fish oil and meal in formulated fish diets
      by oil from more sustainable sources, which may affect the levels of beneficial omega-3 fatty
      acids (EPA and DHA) and other components in fish. We will investigate the health effects of
      consuming two portions oily fish (Scottish farmed salmon) per week (current UK
      recommendation) using fish raised on different feeding regimes.

      HYPOTHESIS

      The health effects of consuming two portions oily fish (Scottish farmed salmon) per week
      (current UK recommendation) will be different for fish raised on different feeding regimes,
      primarily in terms of improving the omega-3 index.

      OBJECTIVE

      The main objective of this proposed study is to determine 1) whether the health benefits of
      consuming two portions of Scottish farmed salmon per week that have been fed a diet high in
      fish oil and fish meal significantly outweigh the health benefits of consuming two portions
      of Scottish farmed salmon per week that have been fed a diet with more sustainable levels of
      fish meal and fish oil, and 2) whether the difference in health benefits could justify the
      use of less sustainable dietary regimes for farmed fish.
    

Intervention name(s): High PUFA Salmon Fillets; Sustainable PUFA salmon; No salmon
Intervention type(s): Other; Other; Other
Intervention description(s): High EPA/DHA levels in feed and in salmon fillets (~15% of total feed fatty acids, equal to wild salmon), 2 salmon fillets per week for 18 weeks, on top of habitual fish consumption.; 'Sustainable' levels of EPA/DHA in feed and in salmon fillets (~6-8% of total feed fatty acids), 2 salmon fillets per week for 18 weeks, on top of habitual fish consumption.; The placebo group will continue to consume their habitual diet.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Prevention
Keywords: Farmed fish; Dietary intervention; Long-term intervention; Omega-3 index; Cardiovascular risk markers; Coagulation and endothelial activation; Bleeding time; Inflammation; Oxidative stress; Gut health; Micronutrient availability