Seafood contaminated with cancer-linked chemicals, finds alarming new study: Worst culprits REVEALED

Seafood on a plate

Seafood is a major source of 'forever chemicals' linked to cancer, researchers warn

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Adam Chapman

By Adam Chapman

Published: 12/04/2024

- 12:39

Updated: 12/04/2024

- 12:48
  • Seafood is a major source of 'forever chemicals' linked to cancer
  • Shrimp and lobster have the highest concentrations
  • Seafood is a dietary staple but clarity needed over limits
  • More than half of UK fruit and veg found to contain toxic PFAs

Seafood contains high levels of toxic 'forever chemicals' linked to cancer and other serious illnesses, a new study has revealed.

Also known as poly and perfluoroalkyl substances (PFAs), forever chemicals can take centuries to break down in the environment.

The chemicals have accumulated in soil, water, and wildlife, and studies have shown that nearly all Americans have measurable amounts in their blood.

Now, a Dartmouth-led study suggests that people who frequently consume seafood may face an increased risk of exposure to PFAs.

Seafood in a bowl

Shrimp and lobster have the highest concentrations 

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The findings stress the need for more stringent public health guidelines that establish the amount of seafood people can safely consume to limit their exposure to perfluoroalkyl and polyfluoroalkyl substances, the researchers report in the journal Exposure and Health.

This need is especially urgent for coastal regions where a legacy of industry and PFAS pollution bumps up against a cultural predilection for fish, the authors write.

"Our recommendation isn't to not eat seafood—seafood is a great source of lean protein and omega fatty acids. But it also is a potentially underestimated source of PFAS exposure in humans," said Megan Romano, the study's corresponding author and an associate professor of epidemiology at Dartmouth's Geisel School of Medicine.

"Understanding this risk-benefit trade-off for seafood consumption is important for people making decisions about diet, especially for vulnerable populations such as pregnant people and children," Professor Romano said.

Worst culprits

Shrimp and lobster clocked the highest concentrations with averages ranging as high as 1.74 and 3.30 nanograms per gram of flesh, respectively, for certain PFAS compounds, the researchers report.

Concentrations of individual PFAS in other fish and seafood measured generally less than one nanogram per gram.

The prevalence of PFAS in the environment makes it difficult to know exactly where and how the chemicals enter the marine food chain, the researchers report.

Some shellfish may be especially vulnerable to the buildup of PFAS in their flesh due to feeding and living on the seafloor, as well as their proximity to sources of PFAS that are near the coast. Larger marine species may ingest PFAS by eating smaller species that, like shellfish, are prone to having the compounds accumulate in their systems.

Person holding packaged salmon in a shop

Strong evidence suggests seafood consumption improves eye, brain and heart health.

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How the researchers gathered their findings

The study paired an analysis of PFAS concentrations in fresh seafood with a statewide survey of eating habits in New Hampshire. National data indicate that New Hampshire—along with all of New England— is among the country's top consumers of seafood, which made the state ideal for understanding the extent of people's exposure to PFAS through fish and shellfish.

The researchers measured the levels of 26 varieties of PFAS in samples of the most consumed marine species: cod, haddock, lobster, salmon, scallop, shrimp, and tuna.

The seafood studied was purchased fresh from a market in coastal New Hampshire and originated from various regions.

Person handling fruit in a supermarket

Forever chemicals found in more than half of UK fruit and veg

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​Editor's take

The new findings highlight the ubiquity of PFAs in the environment and foods we eat. And it comes after Government testing found traces of forever chemicals in more than half of fruit and vegetables sold in the UK.

However, when faced with a finding that seemingly contradicts decades of nutritional advice, it's important to think about the risk to benefit ratio.

PFAs have been linked to cancer, fertility problems and high cholesterol but the role they play in our diet is also an emerging science so we cannot draw conclusions.

For example, the limited human studies into PFAS and cancer are affected by other factors, like people’s genetics, lifestyles and exposure to different chemicals. That makes it difficult to draw a definitive link.

I would defer to the U.S. Food and Drug Administration on this one: "For consumers wondering if they should change their dietary habits related to seafood, we reiterate our recommendation that you and your children eat a variety of healthy foods, including seafood."

We know that seafood provides many nutrients to support a child’s brain and immune system development.

And the benefits extent to adults too: strong evidence suggests seafood consumption improves eye, brain and heart health.

What's more, the study focused on New Hampshire so it's not exactly clear how it translates to a UK context.

However, an analysis of environment Agency (EA) last year did reveal that levels of just one toxic PFAs forever chemical – perfluorooctane sulfonic acid (PFOs) in English freshwater fish are, on average, 300 times higher than proposed new European Union safe levels for aquatic biota.

It's clear that further research needs to be conducted into the problems associated with PFAs and this must be reflected in public health guidance to ensure that people are making informed decisions about what they are putting into their body.

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