With government guidelines urging everyone to eat fish twice a week for heart and brain benefits, you might wonder: If eating two days of fish is good, is eating fish every day better?
Well that question doesn't have a clear cut answer. One expert says that "While it might be safe to eat fish every day, it's still not clear if there is any added health benefits to that level of consumption", Eric Rimm, professor of epidemiology and nutrition. And it's a little complicated because it's not just a health issue, it's also environmental one. Simply put, there are probably not enough fish in the sea for everyone to eat seafood all the time.
But, experts say, eating seafood more than twice a week, for most people, can be healthful. "For most individuals, it's fine to eat fish every day", Eric adds. "And it's certainly better to eat fish every day than to eat beef every day".
However, Eric says, there are some groups- pregnant women, for example- who shouldn't eat certain kinds of fish every day. Larger fish with longer life span like swordfish and tuna tend to bioaccumulate toxins, such as mercury, he explained. "And that's not good for a developing fetus", Eric said. For the same reason, daily consumption on these types of fish is also not good for children, he added.
Mercury is much less of a problem in smaller fish with shorter life spans, according to Theresa Sinicrope Talley, a researcher with the California Sea Grant at the Scripps Institution of Oceanography at the University of California, San Diego.
Mercury won't cause lasting damage in adults, although, it can cause temporary neurological effects. "There are anecdotal reports from places where people eat fish every day of patients complaining of neurological problems, like dizziness or problems concentrating", Eric said. "Those would be people eating maybe sushi or tuna twice a day. You tell them to stop, and sure enough, the mercury levels go down." When that happens, Eric said, the symptoms pass.
As for the question of whether eating fish every day is even more healthy than twice a week, the science is still out on that. Eric Rimm said. "Even to get people eating fish two times a week we need to ramp up fish farming," Rimm says, noting that some types of farmed fish can be more nutritious that those caught in the wild.