Reporting on Microplastics in Seafood Needs Perspective

A recent Australian study about microplastics has been making headlines the past few weeks.

The researchers tested a small handful of seafood products – 5 blue swimmer crabs, 10 farmed Pacific oysters, 10 farmed black tiger prawns, 10 wild Gould's squid and 10 wild sardines – and found trace amounts of microplastics in the samples.

It’s important to note a few things:

  • The objective of the study was to develop a method to improve the detection of plastic contamination.  Finding trace levels of microplastics in seafood does not mean these particles were found in humans who ingest these seafood products. There was no conclusion about the human health impacts of ingesting microplastics through seafood – or any food; that was not studied here. Some news outlets make this point early on, but others bury the lead.
  • Most readers of the news are not scientists and it’s helpful to put into context the level of microplastics found in the samples studied. Some news outlets included in their reporting – noting for comparison reasons, that the average weight for a grain of rice is 30.0 mg
  • With that in mind, the study found the following levels of microplastics in the samples:
    • Sardines: 2.9 mg
    • Crabs: 0.3 mg
    • Oysters: 0.1 mg
    • Prawn: 0.07 mg
    • Squid: 0.04 mg
  • As the Daily Mail pointed out in their reporting, microplastics have been discovered in other food items including apples, carrots, pears, broccoli, lettuce, and meats such as chicken. The researchers themselves point out that microplastics also enter our diets from “bottled water, sea salt, beer and honey, as well as the dust that settles on our meals.” However, science continues to show the largest exposure to humans is from the air. That’s right… breathing. The risks associated with human plastic ingestion – through any means – are not well understood and at this point, scientific research doesn’t support a conclusion that there is a human health concern from microplastics.
  • The researchers studied 45 samples from 5 species, from one area. Headlines that say plastic was found “in all seafood samples” and “100% of the samples” should include the small amount studied in the lead, to not misrepresent the breadth of the study.  The study also noted no measures were put into place to avoid external contamination upon collection (handling by workers or transport in plastic bags), although the samples were washed before analysis.
  • Reams of peer-reviewed nutrition science continue to show the positive health benefits of eating seafood at least 2-3 times per week, including baby brain development and reduced risks of cardiovascular diseaseinflammation and depression. FDA commissioned a report called the “Net Effects Report” that considers both the positive and negative aspects of seafood (such as protein, omega-3s, and minerals as well as things like mercury and contaminants). The conclusion of the report is that the benefits of seafood outweigh theoretical risks, even for pregnant women.

Any new peer-reviewed, published research that increases knowledge about microplastics in food is welcome and important. It’s also important that the media report accurately on such work and does not sensationalize the story or veer into a space saved for public health experts by making uneducated nutrition recommendations. The reality is, seafood continues to be one of the healthiest foods on the planet.

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