Do Fish and Coconuts Reverse Prenatal Stress?

Posted in news, parenting, pregnancy, psychology, science by jenapincott on July 22, 2011

Is it any coincidence that the most laidback people I’ve ever met hail from Brazil, land of fish and coconuts?  

The mellowness of Brazilians came to mind when I read a study on prenatal stress to be published next month in the International Journal of Neurodevelopmental Medicine. The researchers, including lead author Carlos Galduróz, are biologists at  Universidade Federal de São Paulo (in Brazil).

It’s been long known that significant prenatal stress — characterized by a blitz of  the stress hormone cortisol — harms a fetus. Prenatal stress results in an increased risk of premature birth and low birthweight.  In humans, it’s linked with anxiety, attention deficit disorder, impaired memory, low test scores in childhood, and depressive behavior in adulthood.  Rats whose mothers are exposed to extreme stressors are likelier to have impaired motor skills and are slower to learn.

Intriguingly, there’s evidence that the mother’s diet might offset some of these disadvantages.  A baby whose stressed-out mom ate “special” foods during pregnancy and lactation may fare better than one whose equally stressed -out mom ate a normal diet. 

Galduróz and his colleagues were curious to know if the composition of fat in a prenatal diet might make the difference. So, during the equivalent of second and third trimester, they subjected some of the rats in their study to extreme stress — restraint and bright lights for forty-finve minutes, three times daily.  Some of these pregnant rats were fed a diet high in omega-3 fatty acids, the kind found in salmon, sardines, and other fish. Others were fed a diet high in saturated fatty acid from coconut milk. A third group ate normal rat chow.

The results?

As expected, babies of stressed-out moms had lower birth weights.  The surprise came three weeks later:  Babies whose moms ate fish oil or coconut fat diets during pregnancy and lactation gained weight quickly. So quickly, in fact, that they became the same weight as the babies whose moms weren’t stressed during pregnancy.  In other words, fish and coconut fats reversed the impact of low birthweight, a potentially dangerous effect of prental stress.

That’s not all.

Babies exposed to prenatal stress were more active (restless) than other pups if their moms were on a regular or coconut-oil diet.  Interestingly, if a stressed-out mother was on a fish oil diet, her pups were not more restless than those of pups with non-stressed moms.

In an earlier study by the same authors, adult rats whose moms ate a coconut fat or fish oil-based diet released fewer stress hormones (a reduced corticosteroid response) than rats whose moms ate a normal diet.

Many studies have shown that fish oil, omega-3s, modulate mood by reducing the stress response. This has been shown in rat studies, and also in many (but not all) human studies.  Is it possible that when a mother consumes food containing omega-3s, her babies are less agitated? Are they happier?  Of course, rodents express anxiety, neuroticism, and depression differently from human babies.  But the healing effect of nutrients is fascinating.  Do stressed-out moms on fish-and-coconut diets have happier, healthier babies than their equally stressed peers who don’t eat as well?

For the real possibility that  fish and coconut oil have prenatal physical and psychological perks, I link to a favorite recipe here. It’s for moqueca, a stew made of fish and coconut fats, from Bahia, the Coconut Coast of Brazil.

 *If you like this blog, click here for previous posts and here to read a description of my most recent book, Do Gentlemen Really Prefer Blondes?, on the science behind love, sex, and attraction. If you wish, check out my forthcoming book, Do Chocolate Lovers Have Sweeter Babies?: The Surprising Science of Pregnancy. 

 

 

Do Flame Retardants Make Us Dimmer?

Posted in parenting, pregnancy, psychology, science by jenapincott on July 6, 2011

When I was in the second trimester of pregnancy, my husband and I bought a new king-sized mattress.  Like all cotton mattresses sold in the U.S., ours had been treated with a flame retardant containing polybrominated diphenyl ethers (PBDEs) and/or organohalogen compounds (OHCs). Flame retardants are also in pillows, car and airplane seats, drapes, rugs, and insulation. They’re in electronic equipment, like TVs, and in the dust on top of TVs.  They’re in air and soil and breast milk.  Almost all humans have flame retardants flowing through their veins.

             Around the same time I got my new mattress (on which I tossed and turned in third trimester), two surprising studies were published on the effects of flame retardants on fetuses and young children.

Study #1

A group of researchers at the University of Gronigden in the Netherlands recruited nearly 70 pregnant women in third trimester, taking samples of their blood and measuring it for PBDEs and OHCs. Five years later, the children were given standardized developmental tests for motor skills (balance and coordination), cognition (intelligence, spatial skills, control, verbal memory, and attention), and behavior.

The result:  PBDEs were correlated with worse performance on fine motor tasks and a shortened attention span.  Strikingly, they were also linked with better coordination and visual perception, as well as better (more placid?) behavior.  OHCs, meanwhile, were correlated with worse fine motor skills. Oddly, these kids had better visual perception.

 Study #2

 Researchers at Columbia University tested for PBDEs in the cord blood of nearly 400 women who delivered their babies at a New York City hospital.  These children were given mental and motor development tests in infancy and, later, at four-to-six years. These tests measure memory, problem solving, habituation, language, mathematical concept formation, and object constancy.  They also assess ability to manipulate hands and fingers and control and coordinate their movements.

 The result:  At both age intervals, children who had higher cord blood concentrations of PBDEs scored significantly lower on tests of mental (lower IQ) and motor development.  This was particularly evident at age two for motor skills and age four for IQ (nearly 8 points lower for certain PBDEs).

 

            Are flame retardants slowing us down? Correlation is not causation, but there’s a real risk that they do — and researchers have some ideas about how these chemicals have a toxic effects on the brain. OHCs (for instance) have been found to decrease a fetus’s production of thyroid hormone by interfering with thyroid receptors. This leads to an increase in thyroid stimulating hormone (TSH). Brain development in the fetus relies on the precise timing and quantity of thyroid hormone; too much or too little causes developmental delays. High prenatal exposure to TSH is associated with lower IQs – 4 points less on average.  During critical developmental periods, PBDEs and OHCs may also have a toxic effect on neurons in the hippocampus, the memory region of the brain, by reducing the number of neurotrasnmitter receptors.

            Infants and toddlers have what researchers call a high “body burden” of flame retardants. Household dust, which floor-playing infants and toddlers encounter constantly, accounts for 80-93 percent of postnatal PBDE exposure, followed by breast milk (however, the benefits of nursing appear to outweigh this drawback; breastfed babies score higher on neurodevelopmental tests). 

            A disturbing fact is that American kids have levels of PCBEs that are 10 to 1,000 times higher than their peers in Europe or Asia. We produce 1.2 billion pounds of the stuff annually. (Interestingly, the Scandivanian study, whose subjects had lower levels of prenatal exposure, found no IQ deficit while the U.S. study did.) Consider our nation’s problems:  attention deficit disorder, placidity, lower standardized test scores in reading and math.

Are flame retardants making kids dimmer?

            The question fires up the imagination.  Should pregnant women be advised to avoid, say, dusting and buying new mattresses in the same way we avoid emptying the litter box (to avoid toxoplasmosis)? Are the perceived gains in visual perception real, and, if so, why, and do they come at the expense of other abilities? Are urban kids at a higher risk  than average? Are there naturally flame-retardant materials that we can use in lieu of chemicals?   More research, especially on American kids, is warranted.

            After all, the nightmare scenarios can keep an expectant mom up all night, tossing and turning on her nonflammable mattress.

 

 * If you wish, check out my forthcoming book, Do Chocolate Lovers Have Sweeter Babies: The Surprising Science of Pregnancy. 

 

WAAROM VROUWEN CHOCOLA LEKKERDER VINDEN DAN SEKS

Posted in psychology, science, sex by jenapincott on July 4, 2011


The new Dutch mass market edition of Blondes (retitled, in loose translation, “Why Women Prefer Chocolate to Sex”)

The Real Purpose of Eyebrows?

Posted in psychology, science by jenapincott on

Human faces are relatively flat. Alas, evolution has flattened the jutting jaw and the bulging brow ridge. 

Fortunately, we still have one reliable landmark:  the eyebrow.

According to a study by MIT behavioral neuroscientist Javid Sadr and his colleagues, eyebrows have remained because they are crucial to facial identification. Faces without eyebrows are like land without landmarks.

The study:  Volunteers were asked to identify fifty famous faces, including that of former U.S. president Richard Nixon and actor Winona Ryder.  The photos were digitally altered and displayed either without eyebrows or without eyes. When celebrities lacked eyes, subjects could recognize them nearly 60 percent of the time.  However, when celebrities lacked eyebrows, subjects recognized them only 46 percent of time.

The lesson:  eyebrows are crucial to facial identity — they’re at least as important as your eyes, if not more so.  If you put colored contacts in your eyes, pumped collagen into your lips, or put on a pair of funky sunglasses, people would probably still recognize you easily.  But try shaving off your eyebrows. Chances are that everyone will say they didn’t recognize you at first glance.

As Sadr points out, eyebrows pop out against the backdrop of your face — and for that reason not only identify who you are but how you’re feeling. Along with the lips, they may in fact be the most expressive part of your body. The single raised eyebrow is a universal sign of skepticism, and the dual raised eyebrow a sign of surprise.

The shape of your eyebrows also reveals, in a glance, a lot about your age and other characteristics.  Bushy, gnarly, salt-and-pepper brows:  older apha males. Thin, graceful arcs:  young, stylish women.  Sparse, light brows:  youths.  Waxed and tweezed, the brow can advertise good grooming.

Eyebrows sometimes meet each other halfway across the bridge of the nose, especially on men, to form a monobrow, which resembles the vanished browridge of our primate ancestors.  Distinctive? Yes, and also brow-raising.

 *This entry was previously published on this blog. If you wish, also check out my forthcoming book, Do Chocolate Lovers Have Sweeter Babies: The Surprising Science of Pregnancy. 

Archives

Connect on Facebook

Top Posts & Pages