Higher levels of urinary fluoride associated with ADHD in children
October 10, 2018
Science Daily/University of Toronto
Higher levels of urinary fluoride during pregnancy are associated with more ADHD-like symptoms in school-age children.
"Our findings are consistent with a growing body of evidence suggesting that the growing fetal nervous system may be negatively affected by higher levels of fluoride exposure," said Dr. Morteza Bashash, the study's lead author and researcher at the Dalla Lana School of Public Health.
The study, "Prenatal Fluoride Exposure and Attention Deficit Hyperactivity Disorder (ADHD) Symptoms in Children at 6-12 Years of Age in Mexico City," published today in Environment International, analyzed data from 213 mother-child pairs in Mexico City that were part of the Early Life Exposures in Mexico to Environmental Toxicants (ELEMENT) project, which recruited pregnant women from 1994 to 2005 and has continued to follow the women and their children ever since.
Tap water and dental products have been fluoridated in communities in Canada and the United States (as well as milk and table salt in some other countries) by varying amounts for more than 60 years to prevent cavities. In recent years, fierce debate over the safety of water fluoridation -- particularly for children's developing brains -- has fueled researchers to explore the issue and provide evidence to inform national drinking water standards.
The research team -- including experts from the University of Toronto, York University, the National Institute of Public Health of Mexico, University of Michigan, Indiana University, the University of Washington and Harvard School of Public Health -- analyzed urine samples that had been obtained from mothers during pregnancy and from their children between six and 12 years of age to reconstruct personal measures of fluoride exposure for both mother and child.
The researchers then analyzed how levels of fluoride in urine related to the child's performance on a variety of tests and questionnaires that measure inattention and hyperactivity, and provide overall scores related to ADHD. Analyses were adjusted for other factors known to impact neurodevelopment, such as gestational age at birth, birthweight, birth order, sex, maternal marital status, smoking history, age at delivery, education, socioeconomic status and lead exposure.
"Our findings show that children with elevated prenatal exposure to fluoride were more likely to show symptoms of ADHD as reported by parents. Prenatal fluoride exposure was more strongly associated with inattentive behaviours and cognitive problems, but not with hyperactivity," said Bashash.
This work builds off of previous research the team published on this population demonstrating that higher levels of urine fluoride during pregnancy are associated with lower scores on tests of IQ and cognition in the school-age children.
ADHD is the most common psychiatric disorder diagnosed in childhood, affecting between five and nine per cent of all school-aged children.
"The symptoms of ADHD often persist into adulthood and can be impairing in daily life," said Christine Till, Associate Professor of Psychology at York University and co-author on the study.
"If we can understand the reasons behind this association, we can then begin to develop preventive strategies to mitigate the risk," said Till, who is also the principal investigator of another National Institutes of Health-funded grant examining fluoride exposure in a large Canadian sample of pregnant women.
The National Institute of Environmental Health Sciences, part of the National Institutes of Health (NIH), funded this study.
https://www.sciencedaily.com/releases/2018/10/181010132343.htm
Now and Zen: Lower prenatal stress reduces risk of behavioral issues in kids
Study finds mothers who experience significant prenatal stress may be increasing their child's risk for behavioural issues
August 16, 2017
Science Daily/University of Ottawa
Expectant mothers may want to consider adopting today's trend towards stress management, in light of new research pointing to its ability to lower the risk of problematic behavior in their offspring. Researchers found that mothers who are exposed to high levels of stress during pregnancy have kids who are more than twice as likely to have chronic symptoms of hyperactivity and conduct disorder.
Parenting is a complicated journey full of questions, and when a beloved child begins to show signs of a behavioural disorder, a parent's challenges become even more difficult to navigate.
Expectant mothers may want to consider adopting today's trend towards stress management, in light of new research from the University of Ottawa pointing to its ability to lower the risk of problematic behaviour in their offspring.
Dr. Ian Colman, associate professor at the University of Ottawa's Faculty of Medicine, led a team of researchers in examining data from the Avon Longitudinal Study of Parents and Children. The team found that mothers who experience significant prenatal stress may be increasing their child's risk for behavioural issues.
"Mothers who are exposed to high levels of stress during pregnancy have kids who are more than twice as likely to have chronic symptoms of hyperactivity and conduct disorder," Dr. Colman said of the team's recently published findings.
"Hyperactivity is a symptom of ADHD, and about 10% of school-age children are affected by ADHD or conduct disorder," he said. "These disorders can lead to poor results in school and difficulties in their relationships with family and friends."
Behavioural disorders such as those seen by the researchers are characterized by aggressive or antisocial behaviour, high activity levels, and difficulty inhibiting behaviour. They are also associated with school failure, substance use/abuse, and criminal activity, according to the paper.
A mother's stress can alter brain development in the fetus, and it is believed these changes may be long-lasting or permanent, said Dr. Colman.
The team was unique in its approach: it studied the effects of specific stressors on participants, as opposed to gauging overall stress levels. Participants reported stressful events, such as problems at work, the illness of a relative, or an argument with a partner, family or friend. "Generally speaking, we found that the higher the stress, the higher the symptoms," Dr. Colman said. "We can't avoid most stressful events in our lives and since we can't always prevent them, the focus should be on helping mothers manage stress in order to give their children the best start in life."
https://www.sciencedaily.com/releases/2017/08/170816110136.htm
Flame retardants during pregnancy as bad as lead? Exposure linked to lower IQs in kids
May 28, 2014
Science Daily/Simon Fraser University
A new study involving Simon Fraser University researchers has found that prenatal exposure to flame retardants can be significantly linked to lower IQs and greater hyperactivity in five-year old children
Prenatal exposure to flame retardants can be significantly linked to lower IQs and greater hyperactivity in five-year old children. The researchers found that a 10-fold increase in PBDE concentrations in early pregnancy, when the fetal brain is developing, was associated with a 4.5 IQ decrement, which is comparable with the impact of environmental lead exposure. PBDEs have been widely used as flame retardants in furniture, carpet padding, car seats and other consumer products over the past three decades.
PBDEs have been widely used as flame retardants in furniture, carpet padding, car seats and other consumer products over the past three decades. While most items containing PBDEs were removed voluntarily from the market a decade ago, some are still in commerce and others persist in the environment and human bodies. Nearly all homes and offices still contain some PBDEs.
"The results from this and other observational human studies support efforts to reduce Penta-BDE exposures, especially for pregnant women and young children," says Lanphear. "Unfortunately, brominated flame retardants are persistent and North Americans are likely exposed to higher PBDE levels than people from other parts of the world. Because of this it is likely to take decades for the PBDE levels in our population to be reduced to current European or Asian levels."
http://www.sciencedaily.com/releases/2014/05/140528105258.htm
Children who take ADHD medicines have trouble sleeping
Study addresses decades of conflicting evidence of meds' effect on sleep
November 23, 2015
Science Daily/University of Nebraska-Lincoln
Children given ADHD stimulant medications take significantly longer to fall asleep, have poorer quality sleep and sleep for shorter periods, shows new research.
The study addresses decades of conflicting opinions and evidence about the medications' effect on sleep.
In what's known as a "meta-analysis," researchers from the UNL Department of Psychology combined and analyzed the results from past studies of how ADHD medications affect sleep.
In a study published online by the journal Pediatrics, the Nebraska researchers found children given the medicines take significantly longer to fall asleep, have poorer quality sleep, and sleep for shorter periods.
"We would recommend that pediatricians frequently monitor children with ADHD who are prescribed stimulants for potential adverse effects on sleep," said Katie Kidwell, a psychology doctoral student who served as the study's lead author.
About 1 in 14 children and adolescents in the U.S. are diagnosed with ADHD, a chronic condition that includes attention difficulty, hyperactivity and impulsiveness. In the most common form of ADHD treatment, about 3.5 million are prescribed stimulant medications such as Ritalin and Adderall.
Many research articles have been written in the past 30 years on whether ADHD medications harm the ability to sleep. Some researchers have found that the drugs do interfere with sleep, particularly if taken later in the day. Others maintain the medications improve patients with ADHD's ability to sleep, by relieving symptoms and reducing resistance to bedtime. Indeed, some suggest that sleep problems are caused by the medication wearing off near bedtime, creating withdrawal symptoms.
"One reason we did the study is that researchers have hypothesized different effects, and there are some conflicting findings in the literature," said Timothy Nelson, an associate professor of psychology involved in the study. "This is when a meta-analysis is most useful. By aggregating and previous research in a rigorous and statistical way, we can identify the main findings that we see across all these studies. It's essentially a study of studies."
After screening nearly 10,000 articles, Kidwell and her colleagues reviewed 167 full texts before selecting nine studies of sufficient rigor for their analysis. Tori Van Dyk and Alyssa Lundahl, also psychology doctoral students, assisted in the effort.
Studies chosen for the analysis were peer-reviewed, randomized experiments. The studies did not rely on parental reports of their children's sleeping patterns, instead requiring objective measures obtained through clinical sleep studies or wristband monitors used at home.
The researchers found that both methylphenidate medications like Ritalin and amphetamines like Adderall cause sleep problems, without identifying differences between the two. Although they were unable to determine whether varying dosage amounts changed the effect on sleep, they found that more frequent dosages made it harder for children to fall asleep.
They found that drugs tend to cause more sleep problems for boys. The problems dissipate, but never completely go away, the longer children continue to take the medication.
"Sleep impairment is related to many cognitive, emotional and behavioral consequences, such as inattention, irritability and defiance," Kidwell said. "Sleep adverse effects could undermine the benefits of stimulant medications in some cases. Pediatricians should carefully consider dosage amounts, standard versus extended release, and dosage frequencies to minimize sleep problems while effectively treating ADHD symptoms."
She also recommended considering behavioral treatments, such as parental training and changes to classroom procedures and homework assignments, to reduce ADHD's negative consequences.
"We're not saying don't use stimulant medications to treat ADHD," Nelson said. "They are well tolerated in general and there is evidence for their effectiveness. But physicians need to weigh the pros and cons in any medication decision, and considering the potential for disrupted sleep should be part of that cost-benefit analysis with stimulants."
http://www.sciencedaily.com/releases/2015/11/151123202819.htm
Children with ADHD and their mothers may live less than average population
A study conducted by Brazilian researchers shows that hyperactivity can produce chromosome changes that affect health
September 28, 2015
Science Daily/D'Or Institute for Research and Education
Brazilian scientists found that ADHD children and their mothers are more likely to have shorter telomeres, a hallmark of cellular aging, which is associated with increased risk for chronic diseases and conditions like diabetes, obesity and cancer.
Psychiatric disorders like Attention Deficit Hyperactive Disorder (ADHD) impact family's emotions and social life. It is well known. What is new is that this condition also affects the DNA of patients and their parents. Brazilian scientists from the D'Or Institute of Research and Education (IDOR) and the Federal University of Minas Gerais (UFMG) found that ADHD kids and their mothers are more likely to have shorter telomeres, a hallmark of cellular aging, which is associated with increased risk for chronic diseases and conditions like diabetes, obesity and cancer.
Telomeres cap the ends of chromosomes and act as protection against the loss of protein-coding DNA during cell division. While telomere shortening happens naturally with aging, researches indicate the process is accelerated by psychological and biological stress. The shorter the telomeres are, shorter is the biological "life expectancy" of one.
The study, published in Frontiers of Molecular Neuroscience, assessed the length of telomeres from 61 ADHD children (age 6 to 16) and their parents. Even among the children, who are beginning their lives, researchers found shorter telomeres than those that would be expected for their ages. Although mother's telomeres were also shorter, they did not find any alteration in the father's telomere length.
The researchers believe the phenomenon is due to the stress that ADHD symptoms generate for the children and their mothers. Mothers are in most cases the main caretaker of the offspring, showing higher levels of depressive disorders and stress in parenting their children than fathers. ADHD symptoms usually appear during childhood and vary from inattention, hyperactivity and impulsivity -- a combination that can produce negative effects on children's and its relative's lives.
"When people think about behavioral issues with children, they think about the psychological component and how that impacts school performance and interaction with society," points out one of the study's authors, neuropsychiatry Paulo Mattos from IDOR. "These kind of impact are real, but what we are showing for the first time now is that TDAH can impact at the cellular level, at the DNA."
Telomere length is highly heritable. Fathers and mothers with shorter telomeres transmit this characteristic to their children. It means that ADHA children, who already have shorten telomeres, will generate an offspring with shorter telomeres at birth.
The researchers also noticed that hyperactivity symptoms are more related to the telomere length than inattention symptoms. They observed that higher levels of hyperactivity in children were associated with shorter relative telomere in ADHD children and in their mothers.
"This makes sense if you think that hyperactivity is the symptom that affects more negatively the family and causes more stress," say Mattos. "It is usually the reason why parents search for medical care in the first place."
The findings underscore the importance of intervening early to address behavior issues in children to prevent psychosocial stress and shortening of telomeres.
"Decrease the hyperactivity and impulsivity levels in children is fundamental to them and their mothers and this can be achieved by several behavioral techniques applied as soon as possible," affirms another author of the study, geneticist and pediatrician Débora Miranda from UFMG.
http://www.sciencedaily.com/releases/2015/09/150928082158.htm