Friday, June 1, 2012
Fish Consumption - Risks and Rewards Unclear
The public receives fish consumption advice from a variety of perspectives, including toxicant, nutritional, ecological, and economic viewpoints. For example, U.S. federal and state agencies that are concerned about exposure to toxicants in fish, such as methyl-mercury (MeHg) and polychlorinated biphenyls (PCBs), have issued fish consumption advisories recom-mending that at-risk groups limit consumption of fish [U.S. Environmental Protection Agency (EPA) 2004]. However, national organizations of physicians and nutritionists encourage fish consumption for the entire population as a way to increase dietary intake of the n-3 (omega-3) long-chain polyunsaturated fatty acids (LCPUFAs) that may prevent cardio-vascular disease and improve neurological development (Kris-Etherton et al. 2002; Kris-Etherton and Innis 2007; Lee et al. 2009). Also, environmental groups have recommended that consumers avoid certain fish on the basis of concerns about species depletion or habitat destruction consequent to farming methods, site of origin, or type of harvesting (Monterey Bay Aquarium 2011). Whether, how much, and what type of fish a person eats are also influenced by economic and market considerations (e.g., cost and availability) as well as by taste, cultural tradition, recreational habits, and access to alternative foods.
Thus, the consumer who wants to know “which fish should I eat?” is likely to encounter contradictory advice, especially because much of the available information considers a single perspective, such as maximizing health or minimizing ecological harms. For example, because farm-raised salmon is high in n-3 fatty acids and very low in mercury, it is promoted for its nutritional benefits. However, environmental groups consider it a “fish to avoid” because salmon aqua-culture may adversely affect eco-system integrity and wild fish stocks (Monterey Bay Aquarium 2011), and relatively high levels of PCBs have led to concerns about cancer risk (Hites et al. 2004). Furthermore, it may be difficult for consumers to know whether any given fish is “good” to eat because they often do not have access to the facts they need to make fully informed choices, such as the size of the fish or how or where it was caught.