Navigating the mind-boggling maze of fish eating is so complicated that many a conscientious fish eater throw up their hands in defeat. Determining which options are sustainable (a status that shifts with time and depends on a number of variables) and from there figuring out which species offer the least amount of mercury, PCBs and dioxins is a task beyond the bandwidth of most people facing the fish counter. Some markets, like Whole Foods, have stopped the sale of unsustainable fish, but that still leaves matters of toxins a mystery.
If you're a vegetarian, of course, this isn't an issue. But for omnivores and particularly pescatarians who rely on fish for their protein and Omega-3 fatty acids, it's a vexing predicament. And with the Harvard School of Public Health study showing that eating a modest amount of fish per week reduces the risk of death from coronary heart disease by 36 percent and overall mortality by 17 percent, it would be nice for fish eaters to have an easier way.
But now, a group of researchers have found a simple rule of thumb which can be applied.
“If the fish is sustainable, then it is likely to be healthy to eat too,” said Leah Gerber, an associate professor and senior sustainability scientist at Arizona State University.
She and her team conducted an analysis of the existing literature on fish to see which species are regularly healthier and which are high in mercury or overfished. Their findings are published in the on-line version of the Frontiers in Ecology and the Environment, a publication of the Ecological Society of America.
Gerber and collaborating authors (Roxanne Karimi, Stony Brook University, Stony Brook, N.Y., and Timothy Fitzgerald of the Environmental Defense Fund, Washington, DC) note that their study is the first to analyze various types of sustainability rankings, along with species specific health metrics, including omega-3 fatty acid and mercury content.
“In general, larger longer-lived fish are more likely to have exposure to toxins due to the length of their lives and their place on the food chain,” Gerber explained. “So you might be best served to stay away from them – like Bluefin Tuna or Sturgeon. Besides, these stocks have been depleted by fishing.”
Safer choices might be Alaskan Pollock or Atlantic Mackerel, said Gerber.
Gerber said, “Great news for sushi-lovers! Choose the sustainable options and you also are boosting omega-3 intake, without risking mercury poisoning.”