Fish really is brain food – for unborn babies

fish baby

It has long been a saying, in fact more than a saying, more like an ancient wisdom but often dismissed as ‘old wives’ tale’, that fish is brain food. And this has been borne out over the years by various scientific studies that have hailed the inclusion of Omega-3 fatty acids as having numerous health benefits that are good for both mother and baby during pregnancy.

Others, though, have warned against the negative impact of mercury found in some fish, like tuna.

Now, a new study1 across Spain coordinated in Barcelona and funded by the Spanish government, has found that some of the very fish pregnant women are discouraged by some health groups from eating may be the ones associated with the most protective effects on fetal brain development.

Indeed, eating fish like tuna is linked to protective effects on cognitive development and autism symptoms

The study, just published in the American Journal of Epidemiology, looked at approximately 2,000 pregnant mothers across Spain. During pregnancy, the women reported their fish intake via food questionnaires that categorized intake by types of fish. Most of the women ate some fish during pregnancy; the average amount was three servings a week.

During birth, blood from the women’s umbilical cords was assessed for levels of mercury, a contaminant linked to neurotoxic effects, and DHA, an omega-3 fatty acid. After birth, the women’s children were tested on scales for cognitive development and a scale measuring symptoms indicative of autistic spectrum disorder, both when they were 14-months-old and five-years-old.

Eating more servings of seafood a week was associated with increases in cognitive scores and decreases in symptoms of autistic spectrum in the children. Eating 600 grams of total fish per week—about three to four servings—was linked to a 2.8 point increase in IQ score. Unexpectedly, the protective effect was particularly strong for large fatty fish like tuna, which have some of the highest levels of DHA—and mercury—among fish types.

Umbilical cord blood tests revealed higher amounts of mercury and DHA for people who ate more large fatty fish but, interestingly, researchers didn’t see negative associations with mercury and the child’s neurodevelopment.

“It seems that our mercury indicator is telling more about fish consumption, and the positive effect of fish consumption, than the neurotoxic effects of mercury,” says study co-author Jordi Julvez, research fellow at the Centre for Research in Environmental Epidemiology (CREAL) in Barcelona. The benefits tapered off when fish consumption was higher than 600 grams.

How much fish is safe for pregnant women – and what kind – is hotly debated. While the European Food Safety Authority recognizes a benefit to one to four servings of fish per week for mothers-to-be, it recommends limiting fish high in mercury. In the United States, last year’s draft recommendations from the Food and Drug Administration (FDA) revised its position on eating fish during pregnancy. Previously, they’d cautioned women not to eat too much but in the new guidelines, they encouraged women to eat more of it – but only two to three servings a week – and to choose the types lower in mercury and limit their consumption of big predatory fish, such as tuna, which have more mercury.

The study was observational, so it wasn’t designed to determine a cause. But Julvez speculates that DHA omega-3s during pregnancy are the key – especially since other biomarkers for fish intake that they looked at, like vitamin B, didn’t explain the association.

DHA is important in building neurons and cell membranes, he says. And pregnancy seems the most effective time for children to reap the benefits on brain development. “In that specific moment, a large amount of DHA is needed when the brain is growing,” Julvez says.

More research is needed, especially on the role of mercury and whether the positive brain effects last past age 5. But for now, the results suggest that current American recommendations may be too stringent, Julvez and his co-authors write. “Overall, the present results suggest no adverse associations of high seafood consumption in pregnancy with offspring neurodevelopment,” adding that high seafood consumption may even bring some brain benefits.


1 Maternal Consumption of Seafood in Pregnancy and Child Neuropsychological Development: A Longitudinal Study Based on a Population with High Consumption Levels

Jordi Julvez, Michelle Méndez, Silvia Fernandez-Barres, Dora Romaguera, Jesus Vioque, Sabrina Llop, Jesus Ibarluzea, Monica Guxens, Claudia Avella-Garcia, Adonina Tardón, Isolina Riaño, Ainara Andiarena, Oliver Robinson, Victoria Arija, Mikel Esnaola, Ferran Ballester and Jordi Sunyer

Am. J. Epidemiol. (2016) 183 (3): 169-182 first published online January 5, 2016 doi:10.1093/aje/kwv195




Looking at the 12 months ahead of us

genelect queen reign HCFrom left: Spanish party leaders seek coalitions, UK’s Queen Elizabeth II will be 90 in April, Hillary Clinton set to win Democratic nomination but President?

January – now. Spain’s national politicians are trying to put together a coalition to form a government after last month’s general election created a hung parliament for the first time since democracy was restored. They have until January 13 to succeed or a new election will be called. (50shades: It seems no-one wants a second election but to avoid that some tough compromises will need to be made).

March 14 – European Space Agency and Roscosmos plan to launch the joint ExoMars Trace Gas Orbiter on a mission to Mars following postponement of original planned launch on January 7. (50shades: Good to see some international cooperation, if it goes ahead this time).

April 21- Queen Elizabeth II of the UK will mark her 90th birthday. (50shades: So many years of service to her country).

May 5 – National Assembly for Wales election (where we lived before moving to Spain). (50shades: There is likely to be a new party in the Assembly after the election with UKIP possibly gaining as many as 10 seats. This could herald the end to Labour’s monopoly on power and mean a return to coalition rule. The only question being: Which parties would be in such a coalition? Most likely Labour/Plaid Cymru/Liberal Democrats).

May 9 – A transit of Mercury will occur when the planet comes between the Sun and the Earth, and Mercury is seen as a small black dot moving across the face of the Sun. Full transit will be visible in South America, Eastern North America, Western Europe, and a partial transit everywhere else except Australia and far eastern Asia. (50shades comment: Nothing to get excited about, fairly frequent most recent one was in 2006).

May 12-15 A special celebration will take place in the grounds of Windsor Castle, UK, in celebration of the Queen’s 90th birthday.

June 1 – Gotthard Base Tunnel, the world’s longest (35.4 miles) and deepest rail tunnel, is scheduled to be opened in Switzerland. (50shades: The Swiss are good at creating tunnels. This will help trade).

June 10-12 – UK national commemorations to mark the Queen’s 90th birthday.

July 4 – America’s NASA Juno spacecraft is expected to arrive at Jupiter. (50shades: Wait for pictures of Jupiter to fill TV screens and newspapers).

July 18-21 – Republican Party National Convention at Quicken Loans Arena in Cleveland, Ohio. (50shades: Maybe too close to call but, sticking out neck, it will be Ted Cruz as nominated candidate).

July 25-28 – Democratic Party National Convention at Wells Fargo Center, Philadelphia. (50shades: Hillary Clinton will win the presidential nomination).

August 5-21 – 2016 Summer Olympics in Rio de Janeiro, Brazil. (50shades: Expect thrills and spills aplenty plus a scandal or two. Wow, is it really four years since London Olympics?).

September 3 – NASA plans to launch the OSIRIS-REx mission to retrieve a sample from the asteroid Bennu. (50shades: Doubtless it will be a success but what’s the point?)

Sometime in September – China plans to complete the Five hundred metre Aperture Spherical Telescope. (50shades: So China wants its own telescope but will it be any better than what we have now?).

November 1 – Sierra Nevada Corporation plans to launch Dream Chaser, a privately built spaceplane on an unmanned debut mission. (50shades: Sounds interesting).

November 8 – USA presidential election (50shades: Republican candidate, whoever he is, will win).

December 31 – The last remaining American, British and Australian troops ‘will’ withdraw from Afghanistan. (50shades: It won’t happen, there will be a reason why they need to remain).