Skip to content

Category: children

Published on

Huh - all that talk and research for years about the first born being the smartest and most responsible. Yes...but according to this large study comparing 377,00 high school students from different families, the differences are so small as to be meaningless (1 IQ point!). Researchers looking within-families (studying siblings within families) say that the effects are larger. Depends on who you want to believe. And this study did not look at the siblings later in life - at achievements, etc. From Medical Xpress:

Birth order has no meaningful effect on personality or IQ, massive study reports

For those who believe that birth order influences traits like personality and intelligence, a study of 377,000 high school students offers some good news: Yes, the study found, first-borns do have higher IQs and consistently different personality traits than those born later in the family chronology. However, researchers say, the differences between first-borns and "later-borns" are so small that they have no practical relevance to people's lives. The analysis found - as a previous large-scale study did - that first-borns enjoy a one-IQ-point advantage over later-borns, Damian said. The difference is statistically significant but meaningless, she said.

The analysis also revealed consistent differences in personality traits between first-borns and later-borns - first-borns tended to be more extroverted, agreeable and conscientious, and had less anxiety than later-borns, for example - but those differences were "infinitesimally small," amounting to a correlation of 0.02, Roberts said. "But in terms of personality traits and how you rate them, a 0.02 correlation doesn't get you anything of note. You are not going to be able to see it with the naked eye. You're not going to be able to sit two people down next to each other and see the differences between them.."

The study controlled for potentially confounding factors - such as a family's economic status, the number of children and the relative age of the siblings at the time of the analysis - that might skew the results, Damian said. For example, wealthier families tend to have fewer children than other families, and so have a higher proportion of first-borns who also have access to more resources that may influence their IQ or personality, she said.

Many previous studies of birth order suffered from small sample sizes, Damian said. Many compared children with their siblings - a "within-family" design that some assert is better than comparing children from different families, as the new analysis did.

The team also evaluated a subset of the children in the study - those with exactly two siblings and living with two parents. This allowed the researchers to look for specific differences between first- and second-borns, or second- and third-borns. The findings confirmed those seen in the larger study, with specific differences between the oldest and a second child, and between second and third children. But the magnitude of the differences was, again, "minuscule," Roberts said.

Published on

The key finding in this research (they studied mice, but this process would also happen in humans) is that: the presence of microbes specifically blocks the immune cells responsible for triggering allergies. Once again we see the importance of a healthy and diverse microbiota (the community of microbes within us), and the need to nurture it from birth. Studies have shown the importance of the first year of life in establishing a healthy microbiome and the development of the immune system. A number of studies have shown that the presence of pets or animals (e.g., living on a farm) reduces the incidence of allergies in children.From Science Daily:

Role of microbiota in preventing allergies

The human body is inhabited by billions of symbiotic bacteria, carrying a diversity that is unique to each individual. The microbiota is involved in many mechanisms, including digestion, vitamin synthesis and host defense. It is well established that a loss of bacterial symbionts promotes the development of allergies. Scientists at the Institut Pasteur have succeeded in explaining this phenomenon, and demonstrate how the microbiota acts on the balance of the immune system: the presence of microbes specifically blocks the immune cells responsible for triggering allergies. 

The hygiene hypothesis suggests a link between the decline in infectious diseases and the increase in allergic diseases in industrialized countries. Improvements in hygiene levels necessarily lead to reduced contact with microbes that is paralleled by an increased incidence in allergic and autoimmune diseases, such as type 1 diabetes.

Epidemiological studies have substantiated this hypothesis, by showing that children living in contact with farm animals -- and therefore with more microbial agents -- develop fewer allergies during their lifetime. Conversely, experimental studies have shown that administering antibiotics to mice within the first days of life results in a loss of microbiota, and subsequently, in an increased incidence in allergy.

However, until now, the biological mechanisms underlying this phenomenon remained unclear. In this study published in Science, the team led by Gérard Eberl (head of the Microenvironment and Immunity Unit at the Institut Pasteur) shows that, in mice, symbiotic intestinal microbes act on the immune system by blocking allergic reactions.

Several types of immune response can be generated in order to defend the organism. The presence of bacterial or fungal microbes provokes a response from immune cells known as type 3 cells. These immune cells coordinate the phagocytosis and killing of the microbes. However, in the case of infection by pathogenic agents that are too large to be handled by type 3 cells (such as parasitic worms and certain allergens), the cells that organize the elimination of the pathogen, but also allergic reactions, are known as type 2 cells.

In this study, scientists at the Institut Pasteur have shown that type 3 cells activated during a microbial aggression act directly on type 2 cells and block their activity. Type 2 cells are consequently unable to generate allergic immune responses. This work demonstrates that the microbiota indirectly regulates type 2 immune responses by inducing type 3 cells.

These results explain how an imbalance in microbiota triggers an exaggerated type 2 immune response normally used to fight large parasites, but that also leads to allergic responses....In terms of allergy treatment, a hitherto unexplored therapeutic approach consists therefore in stimulating type 3 cells by mimicking a microbial antigen in order to block allergy-causing type 2 cells.

Published on

There is growing evidence that women around a lot of endocrine disrupting chemicals at home or in jobs such as cleaners, hairdressers and laboratory workers during pregnancy are more likely to have baby boys with a genital defect called hypospadias (a condition where the opening of the urethra is on the underside of the penis rather than at the tip). From Environmental Health News:

Genital defect in baby boys linked to moms’ chemical exposure

Mothers around a lot of endocrine disrupting chemicals at home or in jobs such as cleaners, hairdressers and laboratory workers during pregnancy are more likely to have baby boys with a genital defect, according to a new study in the south of France.The study adds to mounting evidence that fetal exposure to chemicals that mimic people’s natural hormones may cause hypospadias, a condition where the opening of the urethra is on the underside of the penis rather than at the tip.

French researchers examined more than 600 children in the south of France and found that babies exposed to endocrine disrupting chemicals while their genitals were developing were more likely to suffer from hypospadias. Half the boys had hypospadias and half did not. The risk for those exposed was 68 percent higher than the unexposed boys. The researchers ruled out baby boys with known genetic risks for such defects.

The defect, which can be minor or quite severe depending on how far the opening is from the tip, can lead to problems with urination and, later in life, sexual difficulty....It is one of the most common genital defects in baby boys, and most cases require surgery, often done before they reach two years old. In the United States, an estimated five out of 1,000 boys are born annually with hypospadias, while Europe’s rate is slightly less than two out of 1,000.

The researchers estimated the unborn babies’ exposure by looking at their parents’ jobs and where they lived. Working with hormone disrupting chemicals and living in homes near heavy polluters were both linked to more baby boys having the defect. However, the researchers did say a limit of the study was attempting to estimate fetal exposure to such chemicals.Mothers were most likely to have boys with hypospadias if they worked as a cleaner, hairdresser or beautician.  

Some of the endocrine disrupting chemicals linked to the professions involved in the study were bisphenol-A (BPA), phthalates, polychlorinated compounds, alkylphenolic compounds and organic solvents. Most exposures—78 percent—occurred in the window of development when babies’ genitals are forming.... but detergents, pesticides, and cosmetics accounted for 75 percent of the cases,” the authors wrote in the study published in the European Urology journal this month.

Other possible causes of the birth defect include older, obese mothers, and fertility or hormone treatments during pregnancy, according to the U.S. Centers for Disease Control and Prevention.

This wasn’t the first time scientists have found a link between certain chemicals and hypospadias. Mothers in southeast England who were heavily exposed to endocrine disrupting phthalates on the job were about three times as likely to have a baby boy with hypospadias. Phthalates are used in some cosmetics, fragrances, food packaging and PVC plastics.

Published on

Two studies showing detrimental effects on children from pyrethroids in 2 weeks! The June 3 post was about research linking household pyrethroid exposure to ADHD in children and young teens. The second study found that low level childhood exposures to pyrethroid insecticides was linked to lower scores on an IQ test (Wechsler Intelligence Scale for Children - verbal comprehension and working memory) in 6 year old children. The researchers viewed this as evidence that pyrethroid insecticides may "negatively affect neurocognitive development".

Bottom line: even though pyrethroid pesticides are considered safer than many other pesticides, they still can have undesirable effects on humans, especially developing children. To be safe, use least toxic pest control that uses non-toxic, safe "alternative" or "natural" methods rather than just "spraying a chemical". Another possibility is looking for "organic pest control" or"least-toxic Integrated Pest Management" (IPM) that looks to deal with pest problems with non-toxic methods (which may include sealing holes, heat, caulking, trapping, using sticky traps, and even vacuuming up insects). From Science Daily:

Impact of insecticides on the cognitive development of 6-year-old children

Researchers have provided new evidence of neurotoxicity in humans from pyrethroid insecticides, which are found in a wide variety of products and uses. An increase in the urinary levels of two pyrethroid metabolites (3-PBA and cis-DBCA) in children is associated with a significant decrease in their cognitive performances , particularly verbal comprehension and working memory. This study was carried out on nearly 300 mother and child pairs from the PELAGIE cohort (Brittany).

Pyrethroids constitute a family of insecticides widely used in a variety of sectors: agriculture (various crops), veterinary (antiparasitics) and domestic (lice shampoo, mosquito products). Their mode of action involves blocking neurotransmission in insects, leading to paralysis. Because of their efficacy and relative safety for humans and mammals, they have replaced older compounds (organochlorides, organophosphates, carbamate) considered more toxic.

Exposure of children to pyrethroids is common. It is different to adult exposure, due to the closer proximity of children to ground-level dust (which stores pollutants), more frequent hand-to-mouth contact, lice shampoos, etc. In children, pyrethroids are mainly absorbed via the digestive system, but are also absorbed through the skin. They are rapidly metabolised in the liver, and mainly eliminated in the urine as metabolites within 48 hours.

Pregnancy is also an important period of life for the future health of the child. For this reason, the researchers studied the PELAGIE mother-child cohort established between 2002 and 2006, which monitors 3,500 mother-child pairs. This cohort simultaneously considers exposure to pyrethroid insecticides during fetal life and childhood. A total of 287 women, randomly selected from the PELAGIE cohort and contacted successfully on their child's sixth birthday, agreed to participate in this study.

Two psychologists visited them at home. One assessed the child's neurocognitive performances using the WISC scale (verbal comprehension index, VCI, and working memory index, WMI). The other psychologist characterised the family environment and stimuli that might have had a role on the child's intellectual development, collected a urine sample from the child, and collected dust samples. Exposure to pyrethroid insecticides was estimated by measuring levels of five metabolites (3-PBA, 4-F-3-PBA, cis-DCCA, trans-DCCA and cis-DBCA) in urine from the mother (collected between the 6th and 19th weeks of pregnancy) and from the child (collected on his/her 6th birthday).

Results show that an increase in children's urinary levels of two metabolites (3 PBA and cis-DBCA) was associated with a significant decrease in cognitive performances, whereas no association was observed for the other three metabolites (4-F-3-PBA, cis-DCCA and trans-DCCA). With respect to metabolite concentrations during pregnancy, there was no demonstrable association with neurocognitive scores.

Published on

New noteworthy research links commonly used household pyrethroid pesticides to attention deficit hyperactive disorder (ADHD) in children and young teens, especially boys. Ome drawback was that the results were based on a single urine sample.Since pyrethroids are non-persistent and rapidly metabolized, then looking at numerous samples over time would have provided a more accurate assessment of typical long-term exposure. Given how many households use pyrethroid pesticides and that there are seasonal variations in pesticide use, then it wouldn't be surprising if there are times when pyrethroid exposure is higher and so the link to ADHD may even be stronger than seen in this original study.From Medical Xpress:

Study links exposure to common pesticide with ADHD in boys

A new study links a commonly used household pesticide with attention deficit hyperactivity disorder (ADHD) in children and young teens.The study found an association between pyrethroid pesticide exposure and ADHD, particularly in terms of hyperactivity and impulsivity, rather than inattentiveness. The association was stronger in boys than in girls.

Due to concerns about adverse health consequences, the United States Environmental Protection Agency banned the two most commonly used organophosphate (organic compounds containing phosphorus) pesticides from residential use in 2000-2001. The ban led to the increased use of pyrethroid pesticides, which are now the most commonly used pesticides for residential pest control and public health purposes. They also are used increasingly in agriculture.

Pyrethroids have often been considered a safer choice because they are not as acutely toxic as the banned organophosphates. Animal studies, on the other hand, suggested a heightened vulnerability to the effects of pyrethroid exposure on hyperactivity, impulsivity and abnormalities in the dopamine system in male mice. Dopamine is a neurochemical in the brain thought to be involved in many activities, including those that govern ADHD.

The researchers studied data on 687 children between the ages of 8 and 15. The data came from the 2000-2001 National Health and Nutrition Examination Survey (NHANES),...included a diagnostic interview of children's ADHD symptoms and pyrethroid pesticide biomarkers. Pesticide exposure measurements were collected in a random sample of the urine of half the 8-11 year olds and a third of the 12-15 year olds. ADHD was determined by meeting criteria on the Diagnosic Interview Schedule for Children,...

Boys with detectable urinary 3-PBA, a biomarker of exposure to pyrethroids, were three times as likely to have ADHD compared with those without detectable 3-PBA. Hyperactivity and impulsivity increased by 50 percent for every 10-fold increase in 3-PBA levels in boys. Biomarkers were not associated with increased odds of ADHD diagnosis or symptoms in girls.

Published on

Interesting, but very preliminary observational research, and there could be various explanations for the results suggesting that the microbiome (community of microbes) of a toddler's gut may influence their behavior. The researchers did not think these differences were diet related, but they had not studied the diet in depth. From Science Daily:

Toddler temperament could be influenced by different types of gut bacteria

The microbiome of a toddler's gut may influence their behavior, a new study suggests. Researchers from The Ohio State University studied microbes from the gastrointestinal tracts of children between the age of 18 and 27 months, and found that the abundance and diversity of certain bacterial species appear to impact behavior, particularly among boys. The correlation exists even after the scientists factored in history of breastfeeding, diet and the method of childbirth -- all of which are known to influence the type of microbes that populate a child's gut. 

Christian and study co-author, microbiologist Michael Bailey, PhD, studied stool samples from 77 girls and boys, and found that children with the most genetically diverse types of gut bacteria more frequently exhibited behaviors related with positive mood, curiosity, sociability and impulsivity. In boys only, researchers reported that extroverted personality traits were associated with the abundances of microbes from the Rikenellaceae and Ruminococcaceaefamilies and Dialister and Parabacteroides genera.

"There is definitely communication between bacteria in the gut and the brain, but we don't know which one starts the conversation," said Dr. Bailey...Overall, associations of temperament with the gut microbiome in girls were fewer and less consistent than boys. However, in girls, behaviors like self-restraint, cuddliness and focused attention were associated with a lower diversity of gut bacteria, while girls with an abundance of Rikenellaceae appeared to experience more fear than girls with a more balanced diversity of microbes.

To identify correlations between gut bacteria and temperament, researchers asked mothers to assess kid's behavior using a questionnaire which measures 18 different traits that feed into three composite scales of emotional reactivity: Negative Affect, Surgency/Extraversion and Effortful Control. Scientists looked at the different genetic types and relative quantity of bacteria found in the toddler's stool samples along with their diets.

Similar to other child behavior studies, researchers separated their findings by gender to analyze temperament. Overall, the study found few differences in the abundance and types of gut microbiota between girls and boys.Both researchers say that parents shouldn't try to change their child's gut microbiome just yet. Scientists still don't know what a healthy combination looks like, or what might influence its development.

Published on

Another good reason to breastfeed. Exposure to pollutants like nitrogen dioxide and airborne particles can cause negative effects on motor and mental development in infants, but a new study says those effects are countered in babies who are breast-fed for at least 4 months by their mothers. Researchers in Spain began monitoring rural, pregnant women in 2006 and analyzed samples from 638 women and their infants at 15 months. They reported that babies who are breast-fed did not suffer from the potentially harmful developmental impact of PM2.5 (pollution particle matter) and NO2 (nitrogen dioxide). From Science Daily:

Breastfeeding protects against environmental pollution

Living in a city with a high level of vehicle traffic or close to a steel works means living with two intense sources of environmental pollution. However, a study conducted by the UPV/EHU researcher Aitana Lertxundi indicates that the harmful effect of PM2.5 pollution particle matter and nitrogen dioxide (NO2) disappears in breastfed babies during the first four months of life. According to the results of the research, breastfeeding plays a protective role in the presence of these two atmospheric pollutants.

Lertxundi's study focusses on the repercussions on motor and mental development during the first years of life caused by exposure to the PM2.5 and NO2 atmospheric pollutants .... "In the fetal phase the central nervous system is being formed and lacks sufficient detoxification mechanisms to eliminate the toxins that build up," pointed out Aitana Lertxundi.

The PM2.5 particles measure less than 2.5 micra, in other words, they are four times thinner that a single hair and are suspended in the air. As they are so small they can easily penetrate the body and as they weigh so little they can spread without any difficulty through the air and can move far away from the initial emission source. The composition of these neurotoxic particles depends on the emission sources in the area. The INMA Gipuzkoa area under study has a high presence of neurotoxic particle matter made up of lead, arsenic and manganese from industrial activity and traffic. In comparison with urban averages where the main source of pollution is traffic, the concentration is lower.

One result of the study is that the existence of an inverse relationship has been detected between exposure to pollution particle matter and the motor development of babies. In this respect, the researcher highlights the fact that "these indices display an alteration with respect to the average and, even if they are not worrying, they are significant in that they reveal the relationship existing between air quality and motor development." The analysis of the data also shows that neither the PM2.5 particle matter nor the NO2 exert a harmful effect on babies breastfed on mother's milk for at least four months.

Published on

Finding endocrine disrupting chemicals in 2 out of 10 baby teethers, which are supposedly safe products for babies, is disturbing. Unfortunately the study did not give the manufacturers names. There was even an 11th teether made of natural rubber that was found to leach compounds that were "cytotoxic"(toxic to living cells), but the manufacturer recalled the product before the study results were published. One of the teethers leaching parabens was made of EVA plastic filled with a cooling gel, and the researchers thought the parabens came from the gel used. Note that this study occurred in Europe where the regulations regarding endocrine disrupting chemicals are stricter than in the USA. The researchers themselves suggest that manufacturers should use "green chemistry" when manufacturing products - that is, design products without using problem ingredients right from the start. Problem solved. From Science Daily:

Endocrine disrupting chemicals in baby teethers

In laboratory tests, two out of ten teethers, plastic toys used to sooth babies' teething ache, release endocrine disrupting chemicals. One product contains parabens, which are normally used as preservatives in cosmetics, while the second contains six so-far unidentified endocrine disruptors. 

"The good news is that most of the teethers we analyzed did not contain any endocrine disrupting chemicals. However, the presence of parabens in one of the products is striking because these additives are normally not used in plastic toys," says Dr. Martin Wagner, of the Department Aquatic Ecotoxicology at the Goethe University. The substances detected -- methyl, ethyl and propyl parabens -- can act like natural oestrogen in the body and, in addition, inhibit the effects of androgens such as testosterone. The EU Commission recently banned two parabens in certain baby cosmetics, because of concerns over their health effects.

"Our study shows that plastic toys are a source of undesirable chemicals. Manufacturers, regulatory agencies and scientists should investigate the chemical exposure from plastic toys more thoroughly," Wagner concludes from the study. The additives have only limited benefits for the quality of the product, but can represent a potential health issue. This is especially true for babies and infants, whose development is orchestrated by a delicately balanced hormonal control and who are more susceptible to chemicals exposures than adults.

Published on

An interesting small study of one family shows how quickly one can eliminate many pesticides from the body by switching to an all organic diet. One Swedish family of 2 adults (aged 40 and 39) and 3 children (aged 12, 10, and 3) who had been eating mainly conventional food were studied.

For the study they only ate conventionally grown food for one week and then they switched to an all organic diet for 2 weeks (fruit, vegetables, meat, fish, etc,). Urine was collected every morning from all family members, and a food diary was kept. Common pesticides and their metabolites were analyzed: atrazine, chlorpyrifos, 2.4-D, pyrethroids, MCPA, chlormequat chloride (CCC) etc.

However, the most commonly used pesticide in the world - glyphosate (Roundup) was not looked at. The results showed that pesticide levels were reduced very quickly once they started eating an all organic diet.

The report also mentioned that currently pesticide standards are only for one pesticide at a time, but people have exposure to many pesticides in daily life (foods, their environment, cleaning supplies, etc) - thus people are exposed to a chemical cocktail that we know very little about about - whether looking at short-term or long-term effects. Article (and video link) from The Sydney Morning Herald:

Family eats organic for just two weeks, removes nearly all pesticides from body

A Swedish family has shown just how quickly an organic diet change can rid the body of pesticides. In a fortnight-long experiment, the family of five - parents Anette and Mats, and kids Vendela, Evelina and Charlie - swapped their conventional diet for an organic one and found that just two weeks of eating an organic diet managed to rid their bodies of most traces of pesticides.

The video explaining the experiment, which was conducted by Swedish supermarket Coop and the Swedish Environmental Research Institute, has been viewed more than a million times on YouTube. 

The researchers measured the levels of plant growth regulators chlormequat chloride, mepiquat, 3-PBA and cleaning agent TCP in urine samples taken from each family member before and after their two weeks of organic eating. Before the experiment, middle child Evelina's urine was showing nearly five nanograms of chlormequat chloride per millilitre. After eating only organic foods for two weeks, the chemical was unable to be detected in her sample. The most profound effects were found in toddler Charlie's samples. Despite his urine before the experiment showing high levels of all four of the chemicals, after the experiment none of the substances were detected.

The original 2015 report Coop Sverige AB, Report number U 5080, from the Swedish Environmental Research Institute: Human exposure to pesticides from food: A Pilot Study  ...continue reading "Eat Organic Foods to Quickly Lower the Pesticide Levels In Your Body"

Published on

In a newly published study looking at how infant gut microbes change over time, once again babies had differences in gut bacteria depending on whether they were delivered vaginally or by Cesarean section.

But what's interesting is that stopping breastfeeding changed their gut bacteria  more (to more adult-like species) than just introducing solid foods. Certain types of bacteria thrive on the nutrients breast milk provides and once these nutrients are no longer available, then other bacteria emerge that are more commonly seen in adults. In other words, stopping breastfeeding seems to drive "maturation" of the gut bacteria.

From The Scientist: Maturation of the Infant Microbiome

Like babies themselves, the intestinal microbiomes of infants start out in an immature state and over time grow into communities similar to those of adults. In a new survey of 98 Swedish babies whose microbiota were sampled several times during their first year of life, researchers found that the microbiomes of breastfed infants persisted in a “younger” state longer than those of non-breastfed babies, even after the introduction of solid foods.

The conclusion that “stopping breastfeeding—rather than introducing solids—drives maturation is a new idea, because we all thought so far that solids introduction was a key factor in changing the microbiota,” said Maria Gloria Dominguez-Bello, a microbiologist at New York University School of Medicine who did not participate in the study.

Researchers from University of Gothenburg in Sweden and their colleagues found more adult-like taxa in the microbiomes of babies who stopped breastfeeding earlier, while the microbiota of babies breastfed for longer were dominated by bacteria present in breastmilk. The results, published today (May 13) in Cell Host & Microbe, are part of an effort to catalog the microbial changes that occur as children age and to note how those changes correlate with health and disease. Fredrik Bäckhed of Gothenburg and his colleagues collected stool samples from 98 moms and their newborns, and again sampled the babies’ stool at four and 12 months.

Confirming previous work, his team’s analysis found that the 15 babies born via cesarean section were colonized by different bacteria—many from oral and skin communities—than babies born vaginally, who shared numerous microbes with those present in their mothers’ stool.

For instance, in the vaginally delivered newborns’ microbiomes, genes that break down sugars in breastmilk were common. As these babies celebrated their first birthdays, the genes in their microbiomes favored the ability to breakdown starches, pectins, and more complex sugars.

“What’s nice about this paper is that they show this maturation [of the microbiome] in normal, healthy kids in a Western population follows this transition based on diet,” said Steven Frese, a postdoc at the University of California, Davis, who penned a commentary accompanying the study with his advisor, David Mills. “Being exposed to new foods promotes the growth of new bacteria that can consume them,” Frese told The Scientist.