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  • Frequent seafood consumption can increase your chance of exposure to dangerous chemicals, according to a new study.
  • For the general public, seafood should be limited to 12 ounces per week.
  • Fish that are high in mercury should be consumed less often.
  • Researchers and experts agree more stringent public health guidelines surrounding seafood intake need to be established.

A new study showed that people who eat seafood on a regular basis may have an increased risk of exposure to PFAS, toxins more commonly described as “forever chemicals” since they remain in the body indefinitely.

Exposure to forever chemicals is linked to health issues such as cancer, fetal abnormalities, high cholesterol, and thyroid, liver, and reproductive disorders.

For the study, published April 12 in Exposure and Health, researchers combined a PFAS concentrations analysis of fresh seafood with a survey of eating habits in New Hampshire. According to national data, New Hampshire is the leading state in seafood consumption.

They measured 26 types of PFAS in the most consumed fish: cod, haddock, lobster, salmon, scallop, shrimp, and tuna. Results showed shrimp and lobster had the highest levels of PFAS compounds.

The survey findings showed that men in New Hampshire eat just over one ounce of seafood per day and women eat just under one ounce. These amounts are more than 1.5 times the national average for adults. For New Hampshire children (2 to 11 years old), it was about 0.2 ounces, which is also higher than the national average.

“The scientific community is working hard to understand more about the overall risk-benefit tradeoff of consuming seafood, Part of the current challenge for consumers is that some of the traditionally safer seafood choices in terms of mercury content may have higher concentrations of other pollutants, like PFAS,” corresponding author Megan Romano, PhD, an associate professor of epidemiology at Dartmouth’s Geisel School of Medicine, told Healthline. “

“This really underscores the importance of eating a balanced diet that incorporates a wide variety of healthy foods. Our study also highlights a need for more consumer-friendly recommendations about seafood consumption,” Romano added.

The findings highlight the importance of establishing public health guidelines that explain the amount of seafood that is safe to consume.

The study authors noted that this is especially important in coastal areas with PFAS pollution.

“Exposure to PFAS via seafood consumption is a function of both the amount of seafood that people eat as well as the concentrations of PFAS in seafood,” first study author Kathryn Crawford, an assistant professor of environmental studies at Middlebury College, told Healthline.

“We found that people in NH consume more seafood on average than other parts of the U.S. Also, the region has been home to PFAS-related industries, which can release PFAS into the environment that can ultimately bioaccumulate in organisms like fish and shellfish,” Crawford added.

When taken together, these findings suggest that people may be exposed to more PFAS than elsewhere, even though the concentrations of PFAS measured in seafood samples in this study are within the range of what has been previously reported in other studies.

Because of this, Crawford and her research team urge the development of public health guidance for seafood consumption that takes these findings into account.

“There needs to be more awareness and strict guidelines on what is considered safe with these chemicals, they are found in so many sources that eliminating them is unlikely although ban their use in future products or providing strict regulations would be ideal,” said Julia Zumpano, a registered dietitian with the Cleveland Clinic center for human nutrition.

“People should limit known sources or PFAS in non-stick cookware, personal care products, cleaning products, grease resistant products, water resistant fabrics, stain resistant products.”

Pregnant people and children are considered the most vulnerable populations when it comes to excessive seafood consumption.

“Pregnancy and early childhood are periods of rapid development with a person’s life, which makes them susceptible to chemical exposures that might interfere with these normal developmental processes,” Crawford said.

“Thus, chemical exposures occurring during pregnancy and early life can have greater effects on health.”

Pregnant and nursing people and young children cannot tolerate chemicals found in certain types of seafood, especially when consumed in large amounts.

“If pregnant and nursing women are exposed to chemicals they can pass those chemicals along to their unborn children or through breast milk,” explained David Love, PhD, an expert in food systems and sustainability and associate professor at John Hopkins Bloomberg School of Public Health.

“When young people are growing their bodies are particularly sensitive to chemical exposures,” Love told Healthline.

Experts agreed the findings of the new study add to our understanding about the risks of PFAS exposure.

“I think we need more studies like this one using different seafood species from around the U.S. and imports of both farmed and wild-caught products to make recommendations about risks from certain fish or shellfish species,” Love said. “PFAS is an emerging risk that we should be aware and continue to monitor and evaluate, but we are not yet able to set national guidance for seafood.”

It’s also important to note there are some types of fish and shellfish that pose less of a threat.

“For the general public, fish (seafood) should be limited to about 12oz per week but fish high in mercury should be very limited in frequency and portion,” Zumpano said.

According to guidelines from the Food and Drug Administration (FDA), the best choices for seafood based on mercury content include:

  • cod
  • crab
  • flounder
  • salmon
  • scallops
  • shrimp
  • canned light tuna

Fish to avoid include king mackerel, marlin, shark, swordfish and tuna, bigeye.

Regarding the guidelines, Zumpano recommended choosing fish from the ‘best choices’ list most often, limit fish from the ‘good choices’ list and avoid fish in the high mercury list.

It’s also a good idea to pay attention to the species of fish, Zumpano said. For example, chunk light tuna has less mercury than albacore or yellowfin.

“Choose low mercury canned tuna, ideally that has been tested for mercury content,” Zumpano said.

A new study showed eating seafood on a regular basis can raise your risk of exposure to toxic chemicals.

Regarding guidelines, the general public should stick to 12oz of seafood per week. However, fish that is high in mercury should be limited.

More stringent public health guidelines surrounding seafood intake should be put in place, experts and researchers noted.