I’m a big, big fan of omega-3 fish oil. I’d add it to every city’s water supply if it didn’t float on top and clog the drains. I personally think if you had to choose only one daily supplement, you should take omega-3 and not a multivitamin. The benefits of omega-3 are exhaustively researched and show special effectiveness to lower triglycerides and decrease heart disease risk. Many doctors are convinced that eating a couple of servings a week of fatty saltwater fish can lower your risk of heart disease by at least a third, perhaps much more. Even in perfectly healthy young women without heart disease, those who ate the most fish had a 90 percent decrease in heart disease compared to those who ate no fish.  Omega-3 is also essential for pregnant moms and infants, as the DHA component of omega-3 is crucial for brain and eye development. That’s why I say it’s good for everybody, young and old.

But the major risk of eating so much fish comes from the all-too-common heavy metals in the fish, especially mercury. Thus we have the endless controversy among pregnant women as to risks and benefits of eating fish. And here in China we have the added uncertainty of general food safety; so just where can we China expats find safe fish to eat? Or should we stick with supplements instead? To help everyone out, I’d like to point out a helpful graph below, with information from a 2006 review in JAMA discussing the data about fish benefits and safety. Take a close look, but the main points include:

• Fish to avoid include swordfish, shark and mackerel (they have the most mercury)
• Salmon is your best bet, with the most amount of omega-3 and generally low levels of mercury
• Farmed salmon has a bit more mercury than wild salmon but the overall levels aren’t too high
• Sardines are another excellent choice and are easily accessible in all expat stores in imported cans
• Trout and shrimp also have some omega-3 and not too much mercury
• Tuna, both canned and fresh, is much less ideal for omega-3 and generally has more mercury, especially albacore

You can also read an outstanding 2008 report on mercury and fish from my favorite food safety website, the Hong Kong Centre for Food Safety. They tested 280 samples of 89 fish and 14 types of canned tuna, and their tests generally matched the above findings. This report is the most relevant I’ve found for our situation in China. One interesting finding was how their imported fish had slightly higher levels of mercury than their local fish — although both averages were in the safe range. In other words, just because a fish is imported doesn’t automatically mean it’s safer than local.

OK, so now we’re all convinced to eat more fatty fish (right?), and ideally we all should have something like salmon at least twice a week. I love the taste of salmon and am very comfortable eating salmon (including sushi) in most restaurants in Beijing. My next bet would be canned sardines. For those of you cooking at home, the same basic rules apply. I don’t think you automatically need to spend a fortune on imported fish (don’t forget sardines!), but those of you who must have imported fish can stock up on frozen imported fish at one of the international hypermarkets such as Metro.

If you’re still worried about eating any fish, local or imported, then you definitely should consider a high-quality fish oil supplement. I don’t know enough about any locally-made brands to be comfortable endorsing, so I stock up on enteric-coated fish oil tablets when I go the US. I recently discovered an even better way: ordering directly from the amazing iherb.com website and getting delivered from the US via EMS within two weeks.

You can read even more about omega-3 from Consumerlab and Natural Medicines Database (subscriptions required but highly recommended!) Here also are some guidelines on pregnancy and eating fish.