Correcting the pollution vs nutrition issue.

Since the discovery of essential fatty acids omega-6 and omega-3 by Burr in 1929, researchers have shown a growing interest in unsaturated essential fatty acids. A number of studies have demonstrated that raised levels of polyunsaturated fatty acids omega-3 (n-3 PUFA) in tissue correlate with a reduced incidence of degenerative coronary heart disease (CHD), some mental illnesses such as depression, and neuro-degenerative diseases such as Alzheimer’s. Fish, especially fatty fish, have long been viewed as a healthy dietary component because of their unique content of n-3 PUFA. An observation in 852 male residents of Zutphen, The Netherlands, and aged 40–59 years in 1960 indicated that fish intake was inversely associated with the incidence of CHD over 20 years of follow-up. Based on these data, WHO recommends that an individual consumes seafood at least 2-3 times a week, to ensure an average daily intake level of 500 mg of EPA+DHA (Eicosapentaenoic acid+Docosahexaenoic acid). On the other hand, there is an increased evidence of environmental pollutants among which persistent organic pollutants (POP), including dioxins that may be introduced with dietary fats. Several foods have been associated to POP and other pollutants and fish does not represent an exception. Therefore, different studies evaluating potential risks v. benefits of fish consumption, especially with respect to CVD, have been performed. Although various results have been reported, it has generally been suggested that the benefits of fish eating outweigh the risks. However, at an experimental level, several pieces of evidence support the idea that the health effects of fish consumption vary depending on the presence or absence of POP. More than half of the total fish for human consumption is provided by aquaculture. Because of the limited natural resource and expensive prices, marine meals and oils used in aquafeeds are often replaced by vegetable ones. As a consequence, fish currently sold in supermarkets are, from a nutritional perspective, considerably different from the fish that were available some years ago. The reduction of EPA+DHA concentration in farmed fish, may thus requests an increase in fish consumption in order to reach the recommended standards. This presentation will focus on the these issues, and will try to give orientations to public, as well as to private, toward research and technological innovations for a reduction of the POP/HUFA ratio in fish for human consumption.