The CALIPSO study on the benefits and risks of high seafood consumption

Dietary consumption of fish and seafood, and concentration levels of trace elements, pollutants and omega 3

The CALIPSO study (for dietary consumption of fish and seafood and concentration levels of trace elements, pollutants and omega 3), which was conducted by the Agency, the French Ministry of Agriculture and Fisheries and INRA between 2003 and 2006 in four French coastal regions, sought to assess the nutritional benefits and risks of contamination that may arise from consuming large amounts of seafood. The main recommendations that resulted from the survey were to diversify consumption of seafood, both with regard to species and sources of supply.

Seafood have valuable nutritional qualities and are especially good sources of minerals such as phosphorus, and trace elements such as iodine, zinc, copper, selenium and fluorine, while some also contain omega 3 fatty acids known as "long-chain" fatty acids (EPA: eicosapentaenoic acid and DHA: docosahexaenoic acid) that prevent cardiovascular disease and are necessary for the development and functioning of the retina, brain and nervous system. However, these foods can also be contaminated by environmental pollutants such as dioxins, PCBs and methylmercury, contaminants that may have adverse effects on health in the event of overexposure.

In this context, the objectives of the CALIPSO study were to acquire data on the behaviour of high seafood consumers (on their eating habits and different sources of supply), on the levels of essential fatty acids, metal trace elements (MTEs) and persistent organic pollutants in the foods consumed, and lastly to measure the biological concentration levels of omega 3 and chemicals in these high consumers (biomarkers in blood and urine).

Main results of CALIPSO

  • the level of contamination of seafood consumed in French coastal areas is generally below the risk thresholds stipulated by the regulations;
  • only those who consume the most seafood absorb significant doses of contaminants, and only slightly higher than the warning levels;
  • no seafood product contains high levels of all contaminants;
  • the fish that contain the highest amounts of omega 3 and persistent organic pollutants are often the same (salmon, mackerel and sardines, in particular);
  • a variety of different seafoods contain metal trace elements;
  • nutritional needs in omega 3 can easily be covered just by eating fish at least twice a week, including one portion of oily fish.

Based on these findings, the Agency has issued the following recommendations:

  • reduce environmental pollution;
  • diversify consumption of seafood, in terms of both species and supply sources;
  • eat fish at least twice a week, not forgetting oily fish;
  • Ffor pregnant or breastfeeding women:
    • limit consumption of predatory fish (2), likely to be highly contaminated, to 150g a week in line with the recommendations of national scientific bodies;
    • do not eat swordfish, marlin or siki, which are likely to contain high amounts of mercury.