The Global Fool

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Prenatal Exposure to Air Pollutants: Links to Attention Deficit Hyperactivity Disorder
Apr11

Prenatal Exposure to Air Pollutants: Links to Attention Deficit Hyperactivity Disorder

By Roberta Attanasio PHAs — short for polycyclic aromatic hydrocarbons — are bad actors: they’re toxic, ubiquitous pollutants that readily cross the placenta, causing damage to the fetal brain. Now, results from a new study show that PHA-induced fetal brain damage may lead to severe behavioral problems during early childhood, including aggression and attention deficit hyperactivity disorder (ADHD). The deleterious effects of air pollution — greater risk of stroke, heart attacks and cognitive deterioration — are widely recognized. However, the new study assessed prenatal exposure and identified specific physical damage in the brain. The researchers used magnetic resonance imaging to measure the brains of 40 children from a cohort consisting of more than 600 mother-baby pairs. The mothers were either Latina (Dominican) or African American nonsmoking women from minority communities in New York City, aged 18 to 35 years. During the third trimester of pregnancy, the women carried personal backpack monitors that measured exposure to eight common PAHs over 48 hours. Such exposure occurred by breathing contaminated air. PHAs — common components of air pollution — are often found together in groups of two or more and persist in the environment for long periods of time. They’re generated by motor vehicles, waste incineration, wildfires and agricultural burning, and oil and coal burning for heat and electricity. Cooking (especially charred foods), tobacco smoke, and space heaters are indoor sources of PHAs. Low-income, urban, and minority communities are disproportionately exposed to these air pollutants. The researchers had previously demonstrated that exposure of the pregnant women from the same cohort to airborne PAHs was associated with multiple neuro-developmental disturbances. Results form the new study indicate that such disturbances have a biological root in the altered architecture of the brain. Specifically, PHA exposure was linked to reductions of the white matter surface in later childhood. These reductions were confined almost exclusively to the left hemisphere of the brain, and involved almost its entire surface. The researchers don’t know why the left side seemed to be affected more, but they suspect the compounds interfere with an early biochemical process that helps the fetal brain divide into slightly asymmetrical hemispheres. Results from the study also show that postnatal PAH exposure correlates with white matter surface measures in other regions of the brain, the dorsal prefrontal regions. Thus, the children involved in the study were exposed to “a double hit”, first as developing fetuses, and then at an early age. Indeed, Bradley Peterson, lead author of the study, told the Los Angeles Times: “It’s a double hit. They have the abnormality from prenatal life throughout the left hemisphere and then on top of that they have...

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Breastfeeding: Positive Influence on the Baby’s Intestinal Microbiota
May22

Breastfeeding: Positive Influence on the Baby’s Intestinal Microbiota

By Roberta Attanasio “Breastfeeding is the normal way of providing young infants with the nutrients they need for healthy growth and development”, the World Health Organization tells us. Breastfeeding confers short-term and long-term benefits on both child and mother, and virtually all mothers can breastfeed, provided they have accurate information, as well as the support of their family, the health care system and society at large. According to the American Academy of Pediatrics, “Babies are born ready to learn to breastfeed. During pregnancy a woman’s body gains weight and changes to support breastfeeding. Think of the first months of life as the “fourth trimester” where you and your baby get to know each other. Breastfeeding is part of getting to know yourself and your baby on a whole different level.” One of the benefits of breastfeeding derives from the influence of breast milk on the gut microbiota — the complex ecological community made up of the trillions of microbes that inhabit the gastro-intestinal tract. This community of microbes is extremely diverse and dynamic — it varies between individuals and it fluctuates according to several factors, as for example age, diet and disease. The gut microbiota colonizes babies at birth, and undergoes many changes during early life. It interacts with the immune system and it drives immune development and maturation from birth. Bruce German, a food scientist (University of California, Davis), told Michael Pollan at the New York Times “Mother’s milk, being the only mammalian food shaped by natural selection, is the Rosetta stone for all food. And what it’s telling us is that when natural selection creates a food, it is concerned not just with feeding the child but the child’s gut bugs too.” Results from recent studies indicate that early exposure to secretory IgA contained in maternal milk is important for maintaining a healthy gut microbiota. Secretory IgA is one of the different types of antibody and is a first line of defense in the intestine — it protects us from harmful microbes and toxins. It is also produced in the mammary gland by a specific cell type, the so-called plasma cell, and is a major component of breast milk. The beneficial effects of maternal secretory IgA persist even after weaning. Now, results from a new study (Establishment of Intestinal Microbiota during Early Life: a Longitudinal, Explorative Study of a Large Cohort of Danish Infants) published this month in the journal Applied and Environmental Microbiology, show that breastfeeding promotes the growth of lactic acid bacteria in the baby’s gut flora — these bacteria are beneficial to the development of the child’s immune system. Tine Rask Licht, one of the researchers involved in the study, said “We have become increasingly aware of how crucially important a...

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Prenatal Exposure to Persistent Organic Pollutants: Influence on Masculine and Feminine Behavior in School-Age Children
Apr18

Prenatal Exposure to Persistent Organic Pollutants: Influence on Masculine and Feminine Behavior in School-Age Children

By Roberta Attanasio Persistent environmental pollutants – such as DDT, dioxins and polychlorinated biphenyls – are a major global health threat. These toxic chemicals resist degradation and persist in the environment for long periods of time. They can be transported by wind and water across international boundaries, and reach regions far from where they are produced or used. People are exposed to these chemicals mostly by eating contaminated fish, meat, and dairy products and, once exposed, may develop a variety of adverse health effects, including birth defects, dysfunctions of the immune and reproductive systems, damage to the central and peripheral nervous systems, and certain cancers. Now, results from a study (Behavioral Sexual Dimorphism in School-Age Children and Early Developmental Exposure to Dioxins and PCBs: A Follow-Up Study of the Duisburg Cohort) published on March 1, 2014 in the scientific journal Environmental Health Perspectives, show that school-age boys and girls exposed to low levels of persistent organic pollutants during fetal life exhibit behavioral changes related to sexual dimorphism – boys show more feminine behavior and girls show less feminine behavior. The study was carried out using the Duisburg cohort, which consisted of 232 healthy pregnant women living in Duisburg, Germany, from September 2000 through October 2002. Duisburg is located in an area that was an important agglomeration for heavy industries. The researchers collected blood samples at 28-43 weeks of gestation and then, after the babies were born, breast milk samples. For the study, all samples were analyzed for presence of dioxins and polychlorinated biphenyls, which are also known endocrine-disrupting chemicals. Once the children reached the age of 6-8 years, parents were asked to report their play behavior, which is known to show profound differences related to gender. For the study, the play behavior was characterized on the basis of “24 items grouped into three categories: preferred toys (e.g., guns, dolls), preferred activities (e.g., playing house, fighting), and behavioral characteristics (e.g., enjoys rough and tumble play, likes pretty things).” For each of these items, parents reported the perceived frequency of occurrence during the preceding month (never, hardly ever, sometimes, often, very often). The researchers found linear dose-response relationships between exposure and outcome – thus, they conclude that low levels of prenatal environmental exposure to dioxins and polychlorinated biphenyls modify behavioral sexual dimorphism in school-age children. Their article has been selected by the Children’s Environmental Health Network (CEHN) as one of the “Articles of the Month” (April 2014 issue). The summary presented by CEHN includes the discussion of the potential policy implications related to the new...

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Breastfeeding: Benefits of Early Exposure to Maternal Antibodies
Feb13

Breastfeeding: Benefits of Early Exposure to Maternal Antibodies

By Roberta Attanasio “Breastfeeding is the normal way of providing young infants with the nutrients they need for healthy growth and development. Virtually all mothers can breastfeed, provided they have accurate information, and the support of their family, the health care system and society at large. Colostrum, the yellowish, sticky breast milk produced at the end of pregnancy, is recommended by World Health Organization as the perfect food for the newborn, and feeding should be initiated within the first hour after birth.” According to the American Academy of Pediatrics, “Babies are born ready to learn to breastfeed. During pregnancy a woman’s body gains weight and changes to support breastfeeding. Think of the first months of life as the “fourth trimester” where you and your baby get to know each other. Breastfeeding is part of getting to know yourself and your baby on a whole different level.” One of the benefits of breastfeeding derives from the influence of breast milk on the gut microbiota — the complex ecological community made up of the trillions of microbes that inhabit the gastro-intestinal tract. This community of microbes is extremely diverse and dynamic — it varies between individuals and it fluctuates according to several factors, as for example age, diet and disease. The gut microbiota colonizes babies at birth, and undergoes many changes during early life. It interacts with the immune system and it drives immune development and maturation from birth. Bruce German, a food scientist (University of California, Davis), told Michael Pollan at the New York Times “Mother’s milk, being the only mammalian food shaped by natural selection, is the Rosetta stone for all food. And what it’s telling us is that when natural selection creates a food, it is concerned not just with feeding the child but the child’s gut bugs too.” Results from recent studies indicate that early exposure to secretory IgA contained in maternal milk is important for maintaining a healthy gut microbiota. Secretory IgA is one of the different types of antibody and is a first line of defense in the intestine — it protects us from harmful microbes and toxins. It is also produced in the mammary gland by a specific cell type, the so-called plasma cell, and is a major component of breast milk. Now, results from a new study published on line (February 3, 2014) in the Proceedings of the National Academy of Sciences (Secretory antibodies in breast milk promote long-term intestinal homeostasis by regulating the gut microbiota and host gene expression) show that the beneficial effects of maternal secretory IgA persist after weaning. In newborn mice and humans, secretory IgA derives almost entirely from breast milk. However, both mice and humans start...

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Lifestyle Factors: Focus on Healthy Pregnancy
Nov30

Lifestyle Factors: Focus on Healthy Pregnancy

By Roberta Attanasio Too many times the medical field views pregnancy in terms of risks leading to potential problems for the mother, the baby, or both. Does it have to be so? Researchers from the UK, Ireland and New Zealand thought this may not be the case and shifted the focus of their research on pregnancy, from abnormality to normality. They carried out a study with the aim of highlighting factors that could be changed before pregnancy and, therefore, increase the likelihood of a normal outcome. Results from their study identified lifestyle factors either beneficial or detrimental for a normal pregnancy. Beneficial factors – factors that increased the likelihood of an uncomplicated pregnancy – were high fruit intake in the month before pregnancy and being in paid employment 15 weeks into pregnancy. Detrimental factors – factors that reduced the likelihood of an uncomplicated pregnancy – were increasing body mass index, increasing blood pressure and misuse of drugs (including binge drinking) in the first trimester. Importantly, these are all factors amenable to improvement. The study, entitled “Exploration and confirmation of factors associated with uncomplicated pregnancy in nulliparous women: prospective cohort study“  (published in the British Medical Journal on November 21, 2013) is based on a group of 5,628 healthy women with singleton births (and no previous pregnancies) enrolled in the Screening for Pregnancy Endpoints study between November 2004 and August 2008 (3196 from Australia and New Zealand and 2432 from the UK and Ireland). According to the researchers (and to the author of an accompanying editorial) the most important next steps are not only to shift the focus of research from abnormality to normality, but also replicate their research approach, show a clear causal relationship between the identified factors and the effects on the outcome of pregnancy, and develop a robust base to guide interventions that can improve the outcome of...

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