Posted: Tue, July 16, 2013 | By: Brain Health
by Hank Pellissier (from Brighter Brains - 225 ways to elevate or injure IQ)
Cousin Marriages - A study co-authored by scientists from Dubai and Switzerland claims that 20-30% of marriages in Arab nations are between first cousins, especially in rural areas, even though this increases the risk of birth defects, due to sharing 12.5% of the genes. Additionally, up to 50% of marriages in these nations are “consanguineous” - between cousins or relatives. The 2009 Reproductive Health Journal report compiled statistics from surveys; here’s a sampling of the rate of cousin marriages in specific countries: Bahrain (45.5%), Egypt (32.8%), Iraq (60%), Jordan (63.7%), Kuwait (64,3%), Qatar (54%), Lebanon (42%), Libya (48.4%), Mauritania (47.2%), Morocco (28%), Oman (56.3%), Pakistan (70%), Palestine (66.3%), Saudi Arabia (66.7%), Numerous studies have examined the cognitive impact. A 1957 report concluded that cousin marriage more than tripled the rate of mental retardation (from 1.3% to 4.6%). A 1965 study of Japanese cousin-marriage revealed an IQ drop of 7 points (from 100 to 93). In 1993, an Aligarh Muslim University, India study showed an IQ drop of 11.2 points (from 99.6 to 88.4). In 2009, Qatar mandated premarital genetic testing for all couples, following the lead of many other neighboring states.
PreNatal Diagnosis - Fetal Screening can determine if fetuses have birth defects or genetic diseases that cause cognitive damage. Diagnoses utilize ultrasonography, MRI, amniocentesis, blood sampling, and numerous other procedures. There are more than four thousand genetic disorders, with every human carrying up to a dozen heritable traits. With genetic testing, mutations can be ascertained in advance in both parents, with an estimate provided of the child’s chances of inheriting the malignancy. Is prenatal diagnosis “expensive”? Perhaps, but the expense is minor compared to the astronomical long-term costs of treating the diseases. A partial list of IQ-impaired conditions: neural tube defects, Downs syndrome (IQ range is 40-70), Tay-Sachs disease, Sickle Cell Anemia (1 in 3 have IQ >75), Klinefelter’s syndrome (-14 IQ points), Fragile X syndrome (80% have < 80 IQ) , Neurofibromatosis (-13 IQ points), WIlliams syndrome (-35 IQ points), Phenylketonuria, aka PKU (IQ average is 91.1), and Prader-Willi syndrome (IQ average is 70). PreNatal diagnosis can also determine damage caused by womb-environment factors (Fetal Alcohol Syndrome, 75 IQ), and injury in intrauterine development (many cerebral palsies).
Older Dads and Moms - A New York State Psychiatric Institute and Columbia University 2005 study discovered “a significant inverted U-shaped relationship between paternal age and IQ scores,” with non-verbal IQ impacted more than verbal IQ. In 2011, researchers at the University of Nijmegen in The Netherlands concluded that “older Dads” produce more genetic mutations typically found in children with IQs <70, due to chromosomal abnormalities caused by copy number variations. Advanced paternal age is also associated with an increased risk for schizophrenia and high-functioning autistic-spectrum disorder. A semi-contrary view was presented in a 2011 Swedish study, that reported offspring of fathers aged 50 years or older have higher GPAs than those of fathers aged 30-34 years. Regarding maternal age, it does not affect autism rates or IQ, claims a 2007 study from Stanford University. Yet another study, by the Max Planck Institute for Demographic Research (Germany), showed no association between advanced paternal age and offspring IQ… but… it did reveal that maternal age above 30 years was “negatively associated with offspring IQ” and “maternal ages 40-44 years were associated with an offspring IQ that was 0.07 standard deviations lower.” Entirely compensating for this small decrease, though, were the IQ points gained via the Flynn effect.
ICSI (intra-cyto plasmic sperm injection) - These fertility treatments that inject sperm cells directly into eggs result in a “slightly greater risk” of lower IQ in offspring, claims a study in Journal of the American Medical Association. The risk increased by 51%, from 62 per 100,000 to 92 per 100,000.
EMBRYONIC NUTRITION AND EXERCISE
Prenatal Iodine Deficiency - Expectant mothers who received iodine supplementation in geographical areas that had inadequate iodine in the diet elevated their children’s IQs by 12.45 IQ points, claims a study conducted in 2005 by Tianjin Medical University. Children born 3.5 years after supplementation began received a boost of 17.25 points. The website micronutrient.org suggests “the loss of intellectual capacity by as much as 10 to 15 percentage points.” A 2012 study by the Swiss Federal Institute of Technology (Zurich) estimates that “iodine-deficient populations experience a mean reduction in IQ of 12-13.5 points.” The World Health Organization labels iodine deficiency the “single greatest preventable cause of mental retardation”—1.5 billion are at risk of contracting Iodine Deficiency Disorder.
Prenatal Folic Acid Deficiency - Women who do not consume enough folic acid are at risk of delivering infants with neural tube defects, claims a 2003 study from State University of New York at Buffalo. Thirty-five percent of children with neural tube defects have IQs at least 15 points below their siblings, and only 15% have “normal standards.”
Prenatal Choline Deficiency - A 2008 Duke University rodent study revealed that choline availability in the embryonic stage created “persistent changes in spatial memory and hippocampal plasticity in adulthood.” Another 2008 study, by Boston University School of Medicine, reported that choline availability in the second half of gestation “produces long-lasting cognitive effects.”
Omega 3 - Adding Omega 3 oils into Mom’s bloodstream will add 7.55 points to their Verbal IQ, suggests a 2008 UK study from Southampton General Hospital.
Possible IQ Impact of Twins, Triplets, etc. - Multiple children that share a womb are at risk of receiving suboptimal nutrition for their developing brains, with adverse neurobiological effects, claims 2010 research by University College London. Heavier monozygotic twins have a verbal IQ that is up to 7.5 points higher than the lighter twin. Differentials increase with triplets, quadruplets, etc. Research published in 2013 from University of Helsinki (Finland) says “Twins and triplets fall slightly behind singletons in cognitive and physical development, even in early adulthood [especially] in families in a low socio-economic position.” A Swedish 2012 study produced a slightly contrary conclusion.: Karolinska Institutet/Stockholm University reported that, “Twins had slightly better mean grade point averages in ninth grade… and more often had completed a university education in young adulthood…compared with singleton siblings, despite male twins having a slightly lower IQ at military conscription compared with male singletons.”
Exercise During Gestation - Pregnant women who exercise 30 minutes a day can increase their baby’s IQ by 8 points, Richard E. Nisbett, author of Intelligence and How to Get It, reportedly told Timesonline.co.uk.
POISONOUS ENVIRONMENTS Fetal Alcohol Syndrome (Heavy Alcohol Exposure) - A Lancet article defines FAS as the leading cause of mental retardation in the Western World. An estimated 2.2 babies out of every 1,000 births emerge with permanent damage to their brain and nervous system. Children born with Fetal Alcohol Syndrome consistently have mental retardation, poor impulse and anger control, facial defects, poor memory, motor skills, social skills, judgement, and sensory integration skills: 60% end up with ADHD and depression; 23% attempt suicide; 70% are suspended, expelled, or drop out of school; 60% are charged or convicted of crimes; 30% are confined to a mental hospital; 80% have employment problems. Children afflicted with fetal alcohol syndrome have an average IQ of 75, notes a 2009 study from the University of Bergen (Norway). A study from University of California - Los Angeles found that children with Prenatal Alcohol Exposure, “returned significantly poorer scores than the non-exposed group on every construct assessed, including executive functioning, attention, working/visuospatial memory, linguistic abstraction, adaptive behavior, emotional/behavioral functioning, and social cognition.”
Moderate Prenatal Alcohol Exposure - Gestating women who imbibe two alcoholic drinks per day hamper their child’s IQ with a 7 point loss, claims a 1990 University of Washington study. Aarhus University (Denmark) found “an effect of maternal consumption of 9 or more drinks per week on attention functions in children.”
Toxoplasmosis gondii is a microscopic parasite that frequently harbors in the gastrointestinal tract of cats. Transmission to humans - via cat feces in kitty litter boxes, soiled garden areas and children’s sandpits, unwashed fruits and vegetables, and undercooked meat - can created toxoplasmosis in humans; an estimated 2-3 billion people worldwide are infected by this protozoa that dwells in muscle and nerve tissue. High rates exist in numerous areas, including rural France (46% of the population), Brazil, and impoverished urban areas of Africa, the Middle East, and SE Asia, especially New Guinea. The least-infected region is South Korea, with a mere 6.7%. Toxoplasmosis is generally harmless in adults with healthy immune systems, but in immuno-compromised humans (such as pregnant women) the impact is enormous. It can also be transmitted congenitally, to newborns. Neurologically, it has been linked to encephalitis, brain cancer, Attention Deficit Hyperactivity Disorder, Obsessive Compulsive Disorder, schizophrenia, depression, and anxiety. Infected subjects have a lower IQ and lower probability of achieving higher education. It’s presence can be ascertained via prenatal testing.
Prenatal Pesticide Exposure - A 2011 UC Berkeley study indicates that high prenatal (and postnatal) exposure to organophosphate pesticides caused a deficit of 7.0 IQ points.
Prenatal Cigarette Exposure - A 1996 University of Mons Hainaut, Belgium, study of women who smoked during pregnancy, concludes, “we found a difference of more than 15 IQ points in favor of the children of nonsmoking mothers.” A 2010 Estonian study of prenatal smoking impact by their National Institute for Health Development found a 3.3 point IQ deficit. A 2005 study by Copenhagen University Hospital, Denmark, recorded a 6.2 IQ point difference. Aarhus University (Denmark) disagreed. It found a decrement of 4 IQ points with smoking 10+ cigarettes per day, but “after adjustment for potential confounders, no significant effects of prenatal exposure to tobacco smoking were found.” McGill University found as association between maternal smoking during pregnancy and lower verbal IQ.
Prenatal Hydrocarbons (Smog) Exposure - A 2009 Columbia University Study revealed that NYC children prenatally exposed to air pollution suffered a 4.31 IQ loss. Children examined in a 2010 Columbia study in Krakow, Poland, showed a 3.8 point IQ loss. A Columbia University study in China concluded that “exposure of pregnant women to emissions of PAHs from the coal-burning plant, in combination with prenatal exposure to environmental tobacco smoke, may have adversely affected cognitive function of children at age 5.”
Prenatal Cocaine Exposure - A Drexel University study in 2008 indicated that boys prenatally-exposed to cocaine had lower IQs at 4, 6, and 9 years of age.
Prenatal Methamphetamine Exposure - A 2009 University of California at Los Angeles study concluded that children with prenatal methamphetamine exposure had a weakened verbal memory system. University of Hawaii 2004 research showed that “meth-exposed children scored lower on measures of visual motor integration, attention, verbal memory, and long-term spatial memory.” The meth exposed children also had “smaller putament bilaterally, smaller globus pallidus, smaller hippocampus volumes, and a trend for a smaller caudate bilaterally. Researchers concluded that “prenatal meth exposure may be neurotoxic to the developing brain.” A later University of Hawaii study reported that “heavy prenatal methamphetamine exposure, along with caregiver psychological distress and child maltreatment, are related to subtle deficits in inhibitory control during the early school-age years.”
Maternal Stress (Elevated Cortisol Exposure) - A 2009 study of 832 children at UC San Francisco concluded that children exposed to elevated cortisol levels in the womb, caused by maternal stress, experienced an average verbal IQ loss of 3.83 points. A 2009 Cambridge University study claimed that high maternal cortisol levels in late pregnancy led to a verbal IQ decrease of 3.83 in the offspring.
Maternal Depression and Anti-Depressants - University of Toronto research examined four groups of children, born to 1) depressed women who took venlafaxine (serotonin-norepinephrine reuptake inhibitor) during pregnancy , 2) depressed women who took selective serotonin reuptake inhibitors (SSRIs) during pregnancy, 3) depressed women who were untreated during pregnancy, and 4) nondepressed women. The resulting IQs were 105, 105, 108, and 112, respectively.
Prenatal Valproate (anti-epileptic drug) Exposure - Embryos prenatally-exposed to Valproate had IQ scores up to 9 points lower than children exposed to other anti-epileptic medications, notes a 2009 Emory University study. A subsequent Emory University study reported that fetal valproate exposure caused adverse cognitive effects that persisted until 4.5 years of age. Verbal abilities were noted as one area of impairment. A Hebrew University of Jerusalem study also showed “reduced non-verbal IQ scores, and lower scores on motor measures, sensory measures, and parent-report executive function, behavioral and attentional measures.”
Prenatal Excess Mercury Exposure - Reports vary. A 2005 Harvard School of Public Health study concluded that excessive prenatal intake of mercury in fish can cost children up to 1.5 points in IQ. Other reports have disagreed. University of Rochester School of Medicine and Dentistry, in their Seychelles Child Development Study. found “no evidence for an adverse effect of prenatal MeHg exposure on development in a cohort that consumes fish daily.”
Prenatal Radiation Exposure - A 1999 study conducted by Belarusian Pedagogical University in Minsk determined that children who were prenatally exposed to radiation via the Chernobyl accident had increased prevalence of speech-language disorders, emotional disorders, and borderline IQ. Children exposed to radiation in uteri also had a mean IQ lower than the control group. The Radiation Effects Research Foundation (Japan) determined that “fetal doses in excess of 100 mGy can result in some reduction of IQ… Fetal doses in the range of 1000 mGy can lead to severe mental retardation and microcephaly…”
Hypothyroxinemia - (abnormally low concentration of thyroxine in the blood) - Fetal “exposure to maternal hypothyroxinemia in the first half of pregnancy” injures cognitive development in infancy and childhood, reports a study from Tilburg University (Rotterdam, The Netherlands).
Maternal Vitamin B-12 Deficiency (NOT A RISK) - A University of Bristol (United Kingdom) study suggests that “maternal vitamin B-12 may not have an important effect on offspring cognitive ability.”
Breech Birth - Males born via breech birth have approximately a 7 point lower IQ than boys who were born in cephalic presentation, claims a 1999 University of Aarhus, Denmark study.
Elective C-Section? Vacuum? - A 1979 German study published in Z Geburtshilfe Perinatol indicated that children “spontaneously born” had an IQ of 108.7. This was significantly lower than children born aided by a c-section (114.4), forceps (116.6) or vacuum (117.7). Another study, in 1991 from Huron Road Hospital, in East Cleveland, Ohio, revealed that IQs of children born via emergency c-section after prolonged labor were “significantly lower” than those delivered after elective c-section with no labor. A third study, by Peking University Health Science Center, reported very small IQ advantages in elective c-section, of 1.6, 2.3, and 0.6 for full-scale, verbal, and performance IQ, respectively.
Premature Birth - Babies delivered at 40+ weeks have bigger heads and bigger brains, and enjoy an average 4.9 points higher IQ than premature infants, reports a 1994 study conducted by the Henry Ford Health Services Center, in Detroit, Michigan. University of Gronigen (The Netherlands) found that performance IQ was 6 points lower in very preterm small-for-gestational-age children, but their verbal IQ was the same. Innsbruck Medical University (Austria) reported delayed numerical skills and lower IQ scores in 20% of children born before 32 weeks of gestation. Harvard Medical School reported that “extremely low birth weight adolescents born in the 1990s have poorer achievement and higher rates of math learning disabilities” than normal birth rate peers.
Moderate Preterm Birth - (born at 32-35 weeks’ gestational age) - University of Gronigen (The Netherlands) research indicated that “moderately preterm children performed significantly worse on total and performance IQ, visuospatial reasoning, attention control, inhibition, and executive functioning. No differences were found in verbal IQ, verbal memory, and visuomotor and motor skills.”
References are available in Hank’s book, Brighter Brains - 225 ways to elevate or injure IQ