Eating seafood can provide a bevy of health benefits. It can reduce the risk of heart disease, boost your brainpower and even keep your skin looking radiant, supple and youthful.

But new research published in the journal Obesity found that a “hidden” ingredient in seafood can actually increase belly fat. And it is this “visceral” fat that is the most dangerous to your health.

Beer Bellies and Muffin Tops… from Pollutants?

In the PIVUS study, researchers measured the levels of 23 persistent environmental toxins in more than 1,000 participants. They also evaluated the amount of belly fat in nearly 300 of the participants using magnetic imaging.

The researchers found that high levels of persistent organic pollutants often found in seafood – including PCBs – were associated with a high proportion of abdominal fat.

So how do these pollutants add inches to your waistline?

They disrupt your hormonal system. This impacts the way fat is metabolized. It also increases cortisol and estrogen levels.

Man-Made “Seafood”: Concentrating the Chemicals

You may wonder how seafood gets contaminated with PCBs in the first place.

The answer is concentrated fish meal.

On average, it takes five pounds of fish meal to produce just one pound of farm raised fish. And this makes farmed fish a highly concentrated source of PCBs.

In fact, the journal Science reports that farmed salmon contain 10 times more toxins (PCBs, dioxin, etc.) than wild salmon. What’s more, seven out of 10 pieces of farm raised fish tested had concentrations of PCBs that were high enough to trigger health warnings from the U.S. Environmental Protection Agency (EPA).

And while belly fat is certainly unsightly, PCB exposure is a lot more serious than just your appearance.  Exposure to PCBs has also been linked to diabetes, heart disease, infertility, thyroid dysfunction, neurological damage, and cancer… as well as memory and learning problems.

Take a look:

  • A study published in Diabetes Care found that people getting the most PCBS and other persistent organic pollutants were almost 3,800% more likely to have diabetes.
  • Infants and children with higher PCB exposures during development can experience lower IQ scores and reduced hearing.
  • Older adults (49 to 86 years old) who ate fish containing PCBs and other contaminants had lower scores on several measures of memory and learning.
  • Fish consumption data shows that nearly a million U.S. adults eat enough PCBs from farmed salmon to exceed the allowable lifetime cancer risk 100 times over!

Worse still, is that PCBs are actually increasing in our seafood supply. Although these chemicals have been banned for many years, the EPA found that PCBs increased 177% in seafood samples between 1993 and 2003.

Choosing Safe, Healthy Seafood

The good news is that you can largely protect yourself from the dangers of PCBs, while still enjoying delicious seafood. Here’s how:

  1. Always choose wild seafood. By law, all fish must be marked wild or farm-raised.
  2. Opt for short-lived species that are relatively low in the food chain (ie- salmon, cod, sablefish, shellfish and sardines)
  3. If you do choose to eat larger, long-living species such as tuna and halibut, pick only younger, smaller members. The longer a fish has lived, the more pollutants it has accumulated over time.
  4. Because 80% of the fish consumed in the Unites States is farm-raised, most restaurant and supermarket fish is contaminated with PCBs and other toxins, such as pesticides and antibiotic residues. When in doubt, pass.

And when shopping for seafood, make sure you buy from a trusted company that only sources wild, sustainable seafood that is independently tested for purity.

Not only will you do a great deal to protect your family from the dangers of PCBs… you’ll also help protect the environment.