Some Gulf Fish, Shrimp Safe, FDA Says

By Mary Pickett, M.D.
Content provided by the Faculty of the Harvard Medical School

U.S. inspectors say that shrimp and fish from parts of the Gulf of Mexico have been tested extensively and found safe to eat. More tests are being done on oyster and crab catches. That was the word from the Food and Drug Administration (FDA) August 16 as shrimp season began. A spill that began in April dumped nearly 5 million barrels of oil into the Gulf. In areas cleared for fishing, levels of oil-related chemicals in fish and shrimp are about the same as those found in non-Gulf waters, the FDA said. Fish and shrimp break down and remove these chemicals from their bodies faster than oysters and crabs do, experts told the Associated Press. The FDA said there's also no reason to fear the chemicals put into the water to break up the oil from the recent spill. The FDA does not believe that these chemicals build up in seafood. The agency is still working on a test for them.

What Is the Doctor's Reaction?

Gulf shrimp fishing season opened Monday, and much of the Gulf has been reopened to fishing. With the oil that is in the Gulf, and the chemicals that were used to scatter oil, is the fish safe to eat? Oysters and crabs are still being tested with extra care. But for fish and shrimp, U.S. agents have given us a "so far, so good" stamp of approval.

The Food and Drug Administration (FDA) is testing fish for chemicals called polycyclic aromatic hydrocarbons (PAH). These compounds are found in crude oil. They can increase the risk of cancer. The FDA is making sure that PAH levels are present in very trace levels or not at all. Dispersant chemicals have been a smaller concern for health.

Fish are given a safe-for-eating bill of health if the level of PAH compounds is less than several parts per billion. The exact amount depends upon which specific chemical is being tested.

With cancer at issue, is this a fair standard to determine safety? Why does the FDA not require that these chemicals be undetectable before saying these fish are fit to eat?

Frankly, it wouldn't be possible for us to eliminate PAH chemicals completely. And that standard probably isn't necessary. In my opinion, the FDA standard is OK.

We ingest PAH chemicals in all sorts of ways, not only by eating fish. Cigarette smoke contains PAH chemicals. They are in the pollution from industry and smoke from regular wood fires. PAH compounds are found in fish in other waters, not just in the Gulf. These compounds also are generated when we grill, fry or barbeque meat.

This doesn't mean PAH compounds are safe. In fact, PAH may be the reason that people who eat beef and other meats "medium well" or "well done" have three times the stomach cancer rate as people who eat their meat "rare" or "medium rare." One study also found higher rates of breast cancer among women who preferred meat "well done."

We do need to be wary of PAH chemicals. But they are too constant a part of our food system and environment for us to entirely avoid them.

Aside from the Gulf oil problem and PAH concerns, there is a mix of good news and bad news about fish for a healthy diet. It's enough to make your head swim.

Here is the good news:

  • Fish is good food. Fish is an excellent source of protein and healthy "long-chain omega-3 fatty acids.'. It is low in saturated fats and cholesterol.

  • Eating fish protects your heart. If you are a diabetic woman, eating fish once a week could reduce your heart attack risk by 35% to 40%. It also can lower your risk of early death. So says a study of more than 5,000 women who kept food diaries for 16 years. In another study, men who were advised to increase the fish in their diet to 200 to 400 grams per week had fewer heart attacks.

  • Eating fish prevents stroke. Men in one study who ate fish at least once per month had a 43 % lower risk of stroke than men who never ate fish.

  • Eating fish prevents dementia. If you eat seafood at least once per week, you probably have a 44% lower chance of being diagnosed with dementia than someone who doesn't eat seafood. Your risk of Alzheimer's disease in particular is 31% lower. This was shown by a study of 1,600 older adults whose eating was monitored for 7 years. Polyunsaturated fatty acids found in fish are thought to help nerve and brain tissue function well.