One Order of Sushi--Hold the Mercury, Please

Photo: wEnDaLicious&39; Flickr photostream/Creative Commons

Thinking about that new sushi restaurant for your big date this weekend? You might think twice. If you care about sparing your lovely lady neurological dysfunction, you might take her to the grocery store instead. A new study published in the online journal Biology Letters says that store-bought sushi is likely to be safer—that is, have lower mercury levels—than the fish that goes in your average dine-out spicy tuna roll.

Over a two year period, 100 samples of sushi were taken from 54 restaurants and 15 supermarkets throughout New York, Colorado, and New Jersey. The samples—bigeye tuna, yellowfin tuna, and bluefin tuna—were then tested for mercury. The results are rather depressing: the average concentrations of mercury for all species were much higher than what's permitted in Japan and deemed safe by the Environmental Protection Agency. 

According to the study, excessive ingestion of mercury is "a health hazard associated with consuming predatory fishes." And it's not a light risk habit. The study also says that excessive ingestion "damages neurological, sensory-motor and cardiovascular functioning."

But there is hope in the grocery aisle: overall, concentrations of mercury were lower in supermarket sushi than in restaurant sushi. One proposed reason is that supermarkets tend to sell yellowfin tuna, a smaller member of the tuna family that is usually caught when young (as a rule, the smaller and the younger the fish, the less mercury it's had time to accumulate in its body). 

The takeaway lesson in all this?  Be smart when you eat: know your options and try to eat low on the seafood chain.