Fish Consumption And Pregnancy

Recently, a study was published in the prestigious journal, Lancet, looking at maternal fish consumption in pregnancy and neurodevelopmental outcomes in childhood.

Over 11,000 pregnant women were assessed for fish/seafood consumption and their children, from ages 6 months to 8 years, were assessed for developmental, behavioral, and cognitive outcomes.

Here’s what they found:

1) Maternal seafood intake during pregnancy of less than 340 g (3/4lb) per week was associated with increased risk of their children being in the lowest quartile for verbal intelligence quotient (IQ)

2) Low maternal seafood intake was also associated with increased risk of suboptimum outcomes for:

• Prosocial behaviour, fine motor, communication, and social development scores

3) For each outcome measure, the lower the intake of seafood during pregnancy, the higher the risk of suboptimum developmental outcome.

In the end, maternal seafood consumption of less than 340 g (3/4 lb) per week in pregnancy did not protect children from adverse outcomes while greater than 340 g (3/4lb) per week benefited the children.

Interestingly, from these data, the researchers suggested that advice to limit seafood consumption could actually be detrimental during pregnancy. According to the researchers:

“Risks from the loss of nutrients were greater than the risks of harm from exposure to trace contaminants in 340 g seafood eaten weekly.”

Of course, the health media, having become quite the cult of debunkers, has run with this – suggesting women now need to eat fish when pregnant; presumably pleased with the ability to debunk another piece of recent nutritional tradition (fish being bad for pregnancy).

However, before anyone gets too carried away with themselves, I’d like to throw in my 2 cents, hopefully a few pennies that avoid the cynic’s bile.

1) First of all, it’s important to avoid getting all crazy about fish, thinking it’s now a miracle food for baby intelligence. They’re talking 3/4 lb a week for the benefits discussed above, folks. And that’s not a lot.

2) Secondly, it’s important to ask what in fish is most important for baby brain development. (And anyone who has Gourmet Nutrition or Precision Nutrition should know the answer to that). It’s the omega 3 content. Which you can get from fish, from fish oil, or from non-fish sources.

3) Finally, it’s clear that different fish from different areas of the world are exposed to different environmental toxins (PCBs, mercury, etc.). Some fish are probably safe. Others not. And you don’t know which are which. So by choosing to eat fish some risk is involved.

So, from these three pieces of information, let’s come up with some logical recommendations here:

1) If you have a low risk tolerance and become pregnant, it may be best to avoid eating fish. Even the 3/4 lb per week discussed above. Instead, supplement with molecularly distilled fish oil. This means all the brain boosting omega 3s and none of the environmental pollutants.

2) If you have a high risk tolerance, love fish, and become pregnant, do eat fish but limit it to 3/4 lb or less per week. But even in this case, supplement with molecularly distilled fish oil anyway.

I know, 30 second sound bites are more tidy than my message above. Yet they’re often incomplete and sometimes downright stupid. So take the popular media messages to eat fish with a grain of salt, just like you take your salmon. And if you’re pregnant, be sure to limit fish intake while adding fish oil to your diet.

Research References:
Study in Lancet – 2007
Maternal seafood consumption of less than 340 g per week in pregnancy did not protect children from adverse outcomes; rather, we recorded beneficial effects on child development with maternal seafood intakes of more than 340 g per week, suggesting that advice to limit seafood consumption could actually be detrimental. These results show that risks from the loss of nutrients were greater than the risks of harm from exposure to trace contaminants in 340 g seafood eaten weekly.

Study in Environmental Health Perspectives – 2005
Higher fish consumption in pregnancy was associated with better infant cognition, but higher mercury levels were associated with lower cognition. Women should continue to eat fish during pregnancy but choose varieties with lower mercury contamination.

Study in Epidemiology – 2004
CONCLUSIONS: When fish is not contaminated, moderate fish intake during pregnancy and infancy may benefit development.

Study in Pediatrics – 2003
CONCLUSION: Maternal intake of very-long-chain n-3 PUFAs during pregnancy and lactation may be favorable for later mental development of children.

Study in Pediatrics – 2003
In conclusion, adding both DHA and ARA when supplementing infant formulas with long-chain polyunsaturated fatty acids supports visual and cognitive development through 39 months.