• An increase in fish consumption in accordance with current dietary advice (2-3 times per week) would probably result in a decreased incidence of cardiovascular disease in the population, particularly in those who eat little or no fish and in those with an increased risk of cardiovascular disease. A considerable proportion of the population aged 50 or over has at least one risk factor for an increased risk of cardiovascular disease.
• Increased fish consumption by women of childbearing age who eat little or no fish would probably be positive. n-3 fatty acids are required for normal development of children during the gestation period and early infancy. Fish consumption 2-3 times a week, with 1 portion consisting of fatty fish, provides a satisfactory intake of long-chain n-3 fatty acids for the majority of the population.
• Intake of vitamin D is low in relation to nutritional recommendations for a large proportion of the population. Increased consumption of fish by those who eat little or no fish would considerably improve the intake of vitamin D. Increased intake of vitamin D contributes to improved vitamin D status and thereby decreases the risk of osteoporosis and fractures.
• Regular consumption of certain types of fish (e.g. fatty Baltic fish and freshwater fish) with increased concentrations of environmental toxins can lead to the so-called tolerable intake levels regarding dioxins/dioxin-like PCBs and methyl mercury being exceeded. This primarily concerns children and women of childbearing age as regards dioxins/dioxin-like PCBs, and pregnant and lactating women and children as regards methyl mercury. However, consumption of these types of fish is low for most individuals.
• An estimated 5% of women in the ages 17-40 years have a dioxin intake that exceeds TDI of 2 pg/kg body weight/day, but many of these eat oily Baltic fish more often than the Administration’s current advice of at most once a month. For a woman who eats fish in accordance with the general advice (lean sea fish/freshwater fish 2 times per week and oily fish, e.g. farmed salmon, 1 time per week) and who otherwise eats a diet in accordance with nutritional recommendations, TDI is not exceeded. However, the proportion that exceeds TDI can be around 35% in the following scenario: Total consumption of fish 3 times per week, of which oily Baltic fish 1 time per month (i.e. corresponding to the current dietary advice) and other oily fish (e.g. farmed salmon) 3 times per month. It is
therefore not advisable to generally recommend an increase in consumption of oily Baltic fish, since the scope for increased consumption is highly limited for certain groups. However there is no reason to completely advise against consumption of oily Baltic fish.
• It should be emphasised that PCB and dioxins are accumulated in the body over a long time and that it is the total body load of these compounds, and not the actual intake, that is critical from a risk perspective. Exceeding the tolerable intake thus does not mean that health effects immediately arise, but that the safety margin decreases.
• Consumption of freshwater fish is low in the population and intake of methyl mercury does not exceed the JECFA’s provisional tolerable weekly intake (PTWI) of 1.6 µg/kg. Limited consumption of fish with up to 1 mg/kg methyl mercury (at most once per month) is estimated to give a small risk of the tolerable intake being exceeded. However, regular consumption of freshwater fish with higher concentrations can lead to the tolerable intake being exceeded. Pregnant women are the group in the population that is most sensitive to methyl mercury due to the greater sensitivity of effects on the foetus.
• In a large proportion of the population there is scope to increase fish consumption without any fear of the tolerable intake levels of environmental pollutants being exceeded. Consumption of the commonest fish species 2-3 times a week, with a mixture of lean and oily fish species, carries a small risk of exceeding tolerable intake levels. The model calculations carried out demonstrate that increased consumption of fish provides health advantages in the form of improved nutrient intake. However, the scope for oily Baltic fish and fish containing high concentrations of MeHg is limited for certain groups.
• In some examples, balanced quantitative risk parameters such as QALYs (Quality Adjusted Life Years) have been applied to fish consumption and the health effects of n-3 fatty acids and methyl mercury have been compared. The net result in the form of positive or negative health effects is dependent on whether the entire population is studied or whether different groups are studied separately.
• In some examples, DALYs (Disability Adjusted Life Years) have been applied to nutritional, microbiological and toxicological food-related aspects in order to estimate the consequences for public health at present and after desirable changes in dietary patterns, incl. increased consumption of fish. The results indicate that an increase in fish consumption would provide health benefits expressed as DALY.
• The scientific basis at present does not allow balanced quantitative risk/benefit assessments of all the health effects associated with fish consumption. However from a consumer perspective it is an advantage for experts from different disciplines to jointly draw up a complete picture that illustrates both risk and benefit aspects. This area is being developed and should be actively monitored by the National Food Administration.