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Another study finding brain changes from playing tackle football - this time measurable brain changes were found in boys 8 to 13 years old after just one season of playing football. None of the boys had received a concussion diagnosis during the season. The changes in the white matter of the brain (and detected with magnetic resonance imaging (MRI) were from the cumulative subconcussive head impacts that occur in football - the result of repetitive hits to the head during games and practices.

No one knows if the brains of football players fully recover after the football season. But these findings are worrisome. Especially because last year researchers found that NFL players who had begun playing  football before age 12 had a higher risk of altered brain development, as compared to players who started later (see post). Currently nearly 3 million students participate in youth tackle football programs across the United States. Some are calling for young players to only play flag or touch football, and to only play tackle football starting with the teenage years. From Science Daily:

Brain changes seen in youth football players without concussion

Researchers have found measurable brain changes in children after a single season of playing youth football, even without a concussion diagnosis, according to a new study published online in the journal Radiology.

"Most investigators believe that concussions are bad for the brain, but what about the hundreds of head impacts during a season of football that don't lead to a clinically diagnosed concussion? We wanted to see if cumulative sub-concussive head impacts have any effects on the developing brain," said the study's lead author, Christopher T. Whitlow, M.D., Ph.D., M.H.A., associate professor and chief of neuroradiology at Wake Forest School of Medicine in Winston-Salem, N.C.

The research team studied 25 male youth football players between the ages of 8 and 13. Head impact data were recorded using the Head Impact Telemetry System (HITs), which has been used in other studies of high school and collegiate football to assess the frequency and severity of helmet impacts....The study participants underwent pre- and post-season evaluation with multimodal neuroimaging, including diffusion tensor imaging (DTI) of the brain. DTI is an advanced MRI technique, which identifies microstructural changes in the brain's white matter. 

The brain's white matter is composed of millions of nerve fibers called axons that act like communication cables connecting various regions of the brain. Diffusion tensor imaging produces a measurement, called fractional anisotropy (FA), of the movement of water molecules in the brain and along axons. In healthy white matter, the direction of water movement is fairly uniform and measures high in FA. When water movement is more random, FA values decrease, which has been associated with brain abnormalities in some studies.

The results showed a significant relationship between head impacts and decreased FA in specific white matter tracts and tract terminals, where white and gray matters meet. "We found that these young players who experienced more cumulative head impact exposure had more changes in brain white matter, specifically decreased FA, in specific parts of the brain," Dr. Whitlow said. "These decreases in FA caught our attention, because similar changes in FA have been reported in the setting of mild TBI."

It is important to note that none of the players had any signs or symptoms of concussion."We do not know if there are important functional changes related to these findings, or if these effects will be associated with any negative long-term outcomes," Dr. Whitlow said. "Football is a physical sport, and players may have many physical changes after a season of play that completely resolve. These changes in the brain may also simply resolve with little consequence. However, more research is needed to understand the meaning of these changes to the long-term health of our youngest athletes." [Original study]

Lead exposure is a big problem for children throughout the United States and the rest of the world - whether lead from plumbing, lead paint, lead solder, and even from nearby mining. There are no safe levels of lead in children (best is zero) because it is a neurotoxicant - thus it can permanently lower IQ scores as well as other neurological effects. More lead gets absorbed if the person also has an iron deficiency than if the person has normal iron levels.

This study found that simply eating iron fortified biscuits daily lowered lead levels (and improved iron levels) in children during a several month period. Two types of iron supplements were tested, and it was found that sodium iron EDTA (which is commonly added to foods) worked better than iron sulphate. The CDC (Centers for Disease Control) recommend eating foods high in calcium, iron, and vitamin C to lower iron absorption. From Science Daily:

Iron supplements in the fight against lead

Lead is a toxic heavy metal that was added to gasoline for use in cars until as recently as 25 years ago. It is particularly harmful to the developing brains of infants, children and teenagers, and the damage it does is irreversible. The situation becomes significantly worse if people are exposed to a high level of lead at the same time as they are suffering from iron deficiency. In the small intestine, lead and iron bind to the same transport protein, which absorbs the metals into the bloodstream. If someone consumes too little iron with their food, the transporter increases its activity, and can carry lead into the bloodstream instead, leading to increased levels of the toxic heavy metal in the body and brain.

A team of researchers led by ETH professor Michael B. Zimmermann from the Laboratory of Human Nutrition have now shown in a study that fortifying food with iron produces a striking reduction in blood lead concentration in children exposed to high levels of the metal. This is the result of a trial involving over 450 children carried out by Zimmermann's former doctoral student Raschida Bouhouch and colleagues in southern Morocco.....Mining in the surrounding area meant that children of preschool and school age were exposed to an increased quantity of lead. At the same time, the level of iron in their blood was relatively low, placing them in a high-risk group.

Depending on their weight, the children were given several white-flour biscuits on a daily basis for a period of four and a half months. The biscuits were fortified with different iron preparations: some received biscuits containing a specific quantity of iron sulphate, while others received biscuits with sodium iron EDTA or sodium EDTA without iron. To test the effect of the iron supplements, some children received only placebo biscuits containing no additional iron. EDTA, which stands for ethylene diamine tetraacetic acid, forms stable complexes with iron, aiding its uptake into the bloodstream from the intestines, but it is not absorbed itself. EDTA can also bind to lead in the intestines, reducing its absorption....Sodium iron EDTA has already been used for iron fortification in foodstuffs for many years.

The researchers measured the children's blood lead concentration and iron status before and after the trial, as well as conducting tests to determine how well the children could solve cognitive tasks. The researchers were delighted to find that the biscuits fortified with iron did indeed reduce the level of lead in the blood -- specifically, by a third with sodium iron EDTA complexes and by a quarter with EDTA and iron sulphate.

Before the study began, the children's blood contained on average 4.3 micrograms of lead per decilitre. Biscuits with added sodium iron EDTA facilitated a reduction in blood lead concentration to 2.9 micrograms per decilitre. The biscuits also brought about an improvement in the children's iron status. On the other hand, the reduction in lead concentration had no effect on cognitive performance, as the researchers discovered during the corresponding tests. Although, contrary to the researchers' expectations, the children's blood lead concentration before supplementation with iron was in line with the worldwide average at 4.3 micrograms per decilitre of blood, it was still possible to achieve a considerable reduction by administering the biscuits.  

Many articles have been written about endocrine disrupting chemicals and the numerous health problems they're linked to (see posts on them). It's been known for decades that endocrine-disrupting chemicals pose a danger to human health because the compounds can interfere with natural hormone function. Chemical exposure occurs through routine contact with plastic bottles, vinyl items, toys, food cans, cosmetics, flame retardants, and other consumer products containing "endocrine-disrupting chemicals". We ingest, breathe them in (inhalation), or absorb them through the skin as consumer products are used and also as consumer products break down (the dust).

Finally a study examines the financial cost of these chemicals - an estimate of more than $340 billion annually due to health care costs and lost wages (the authors say this is a conservative estimate). What can ordinary people do to lower their exposure to these chemicals? Avoid the use of pesticides in the home, lawns, and gardens. Eat as much organic foods as possible. Avoid buying food in cans, including soda. Store food in glass and stainless steel containers. Avoid microwaving in plastic containers (use glass instead). Avoid plastic bottles with the numbers 3, 6, and 7 on the bottom. Avoid vinyl items such as vinyl shower curtains and vinyl toys. Avoid fragrances (get unscented products). Read labels on lotions, shampoos, soaps, make-up - avoid phthalates and parabens. Avoid flame retardants (check the labels on new upholstered furniture). Avoid non-stick pots, avoid stain-repellant items, avoid air fresheners and dryer sheets. And that's just a partial list....From Environmental Health News:

Toxic economy: Common chemicals cost US billions every year

Exposure to chemicals in pesticides, toys, makeup, food packaging and detergents costs the U.S. more than $340 billion annually due to health care costs and lost wages, according to a new analysis. The chemicals, known as endocrine disruptors, impact how human hormones function and have been linked to a variety of health problems such as impaired brain development, lower IQs, behavior problems, infertility, birth defects, obesity and diabetes. The findings, researchers say, "document the urgent public threat posed by endocrine disrupting chemicals.”   ...continue reading "Exposure to Common Chemicals Costs the US $340 Billion Each Year"

Recent research examined levels of endocrine disruptors called phthalates in people eating fast food. Researchers found evidence of a dose–response relationship between fast food intake and exposure to phthalates - the more one eats fast food, the more phthalates (actually metabolites of the phthalates) can be measured in the person's urine. Fast food consumers had higher urinary levels of the phthalates DEHP, DiNP, and BPA than those not consuming fast food (even though the differences in levels of BPA among groups were "non-significant"). This is of concern because these endocrine disruptors are linked to a number of health problems. (Earlier discussion of this research.)

DEHP, DiNP, and BPA are detected in over 90% of the population in the US, but since there are many health concerns - it is better to have lower levels than higher levels. (Zero levels would be best). Note that phthalates and BPA are quickly metabolized and excreted in urine, with elimination half-lives of less than 24 hr - which is why the study looked at what had been eaten in the last 24 hours. But this also shows that one can quickly reduce their levels in the body.

Some possible sources of phthalate contamination in fast food are: PVC tubing, vinyl gloves used for food handling, and food packaging, including beverage cans - the chemicals leach or migrate out into the food and then are ingested. (More on chemicals migrating from containers to food), Fast food was defined as food obtained from restaurants without waiter service and from pizza restaurants, as well as all carry-out and delivery food. Another excellent reason to cut back on fast food (like we don't have enough reasons already!). The following news report discusses the research. From Environmental Health Perspectives:

Phthalates in Fast Food: A Potential Dietary Source of Exposure

Many research studies have surveyed nutritional habits, but fewer have studied how food processing and packaging might introduce unwanted chemicals into foods. In this issue of EHP, researchers report that fast food consumption appears to be one source of exposure to the chemicals di(2-ethylhexyl) phthalate (DEHP) and diisononyl phthalate (DiNP).1

The authors used data from the National Health and Nutrition Examination Survey (NHANES) to estimate the percentage of individuals’ calories that came from fast food, fat intake attributable to fast food consumption, and fast food intake by food group. During NHANES interviews, respondents had reported their diet from the preceding 24 hours. Fast food was defined as food obtained from restaurants without waiter service and from pizza restaurants, as well as all carryout and delivery food.2 ....The final study population included nearly 9,000 people aged 6 years or older. Approximately one-third of people surveyed had eaten fast food in the preceding 24 hours. Study participants who ate fast food were more likely to be male, under age 40, and non-Hispanic black, and to have higher total calorie and total fat intake from fast food, compared with the general population.1

Fast food consumers had higher urinary levels of DEHP, DiNP, and BPA than non-consumers, although the differences in average urinary levels were small and for BPA were non-significant. When fast food intake was categorized by food group, DEHP metabolites were associated with intake of grains and “other” (a category that included vegetables, condiments, potato items, beverages, and more). DiNP metabolites were associated with intake of meat and grains.1

The authors also found that the associations between phthalates and fast food were not uniform across the population.1They speculate that the pronounced association they saw between fast food consumption and DEHP in black consumers could reflect higher overall consumption of fast food and/or different food choices among this population. Prior research suggests that predominately black neighborhoods in urban areas have a greater density of fast food restaurants than white neighborhoods.3

The authors point to PVC tubing, vinyl gloves used for food handling, and food packaging as possible sources of phthalate contamination in fast food. DEHP is a ubiquitous high-molecular-weight phthalate that has been removed from some products due to concerns about potential adverse health effects.5 In some cases it is being replaced with DiNP.2

The related Environmental Health Perspectives research article:  Recent Fast Food Consumption and Bisphenol A and Phthalates Exposures among the U.S. Population in NHANES, 2003–2010

Experimental animal studies demonstrate that DEHP and DiNP have endocrine-disrupting properties because of their anti-androgenic effects on the male reproductive system (National Research Council 2008). Human exposure to DEHP has been associated with adverse reproductive, neurobehavioral, and respiratory outcomes in children (Braun et al. 2013; Ejaredar et al. 2015) and metabolic disease risk factors such as insulin resistance in adolescents and adults (James-Todd et al. 2012; Attina and Trasande 2015). Though epidemiologic evidence of DiNP is less complete, recent studies report associations between exposure and similar health outcomes including adverse respiratory and metabolic outcomes in children (Bertelsen et al. 2013; Attina and Trasande 2015). BPA is also a suspected endocrine disrupter, and experimental and human evidence suggest that BPA is a reproductive toxicant (Peretz et al. 2014). In addition, prenatal BPA exposure has also been associated with adverse neurobehavioral outcomes in children (Mustieles et al. 2015).

Given the concern over chemical toxicity, it is important to identify modifiable sources of exposure that may be targeted for exposure reduction strategies. Simulated exposure modeling, observational epidemiologic studies, and intervention studies all suggest that diet is an important exposure pathway for both high-molecular-weight phthalates and BPA.....Phthalates have been shown to leach into food from PVC in materials like tubing used in the milking process, lid gaskets, food preparation gloves, conveyor belts and food packaging materials (Cao 2010;Serrano et al. 2014). In fact, an intervention study reported that urinary BPA and DEHP were reduced by 66% and 53–56%, respectively, when participants’ diets were restricted to food with limited packaging (Rudel et al. 2011). Foods high in fat, such as dairy and meat, may be more contaminated by high-molecular-weight phthalates that are more lipophilic such as DEHP (Serrano et al. 2014). Fast food may be an important source of exposure to phthalates and BPA because it is highly processed, packaged, and handled.

This study reinforces (once again) that actively playing with toy blocks is good for developing the spatial skills and spatial abilities of children. Other studies have shown that playing with puzzles and actively going out and exploring their environment (like riding a bicycle around the neighborhood) are also good for developing spatial skills and spatial abilities. For both boys and girls. Even though unfortunately this study only looked at 8 year old boys. (Hey, where were the girls???) Remember that playing is how children learn, and helping develop spatial skills is good for math, science, and technology. So get out the Legos and toy blocks and encourage children to play and build! From Medical Xpress:

Neuroimaging study: Building blocks activate spatial ability in children better than board games

Research from Indiana University has found that structured block-building games improve spatial abilities in children to a greater degree than board games. The study, which appears in the journal Frontiers in Psychology, measured the relative impact of two games—a structured block-building game and a word-spelling board game—on children's spatial processing, including mental rotation, which involves visualizing what an object will look like after it is rotated. The research lends new support to the idea that such block games might help children develop spatial skills needed in science- and math-oriented disciplines.

Block play changed brain activation patterns," Newman said. "It changed the way the children were solving the mental rotation problems; we saw increased activation in regions that have been linked to spatial processing only in the building blocks group." The structured block-building game used for the study was called "Blocks Rock"; the board game was Scrabble.

The research builds upon previous studies that have shown that children who frequently participate in activities such as block play, puzzles and board games have higher spatial ability than those who participate more in activities such as drawing, riding bikes, or playing with trucks and sound-producing toys.

It is also demonstrates that training on one visuo-spatial task can transfer to other tasks. In this instance, training on the structured block-building game resulted in transfer to mental rotation performance.....To conduct the study, IU researchers placed 28 8-year-olds in a magnetic resonance imaging scanner before and after playing one of the two games. Play sessions were conducted for 30 minutes over the course of five days.

There were no differences in mental rotation performance between the two groups in either the brain activation or performance during the first rotation test and scan. But the block play group showed a change in activation in regions linked to both motor and spatial processing during the second scan. The group who played board games failed to show any significant change in brain activation between the pre- and post-game scans, or any significant improvement on the mental rotation test results.

 Scans of the children's brains show increased activation in the anterior lobe of the cerebellum and the parahippocampus during the second mental rotation test, which was administered after they played with blocks. Credit: Indiana University

Ten chemicals suspected or known to harm human health are present in more than 90% of U.S. household dust samples, according to a new study. The research adds to a growing body of evidence showing the dangers posed by exposure to chemicals we are exposed to on a daily basis. The chemicals come from a variety of household goods, including toys, cosmetics, personal care products, furniture, electronics, nonstick cookware, food packaging, floor coverings, some clothing (e.g., stain resistant), building materials, and cleaning products. How do the chemicals get into the dust? The chemicals can leach, migrate, abrade, or off-gas from the products, which winds up in the dust and  results in human exposure. (That's right:  vacuum a lot and wash your hands a lot, and try to avoid or cut  back use of products with these chemicals,)

What was found in the dust? The main chemicals were: phthalates — a group of chemicals that includes DEP, DEHP, DNBP and DIBP (these were present in the highest concentrations),  highly fluorinated chemicals (HFCs), flame retardants (both old and newer replacement ones), synthetic fragrances, and phenols. These chemicals are known to have various adverse health effects, including endocrine disruption, cancer, neurological, immune, and developmental effects. (See posts on endocrine disruptors and flame retardants) Studies typically study one chemical at a time, but household dust contains MIXTURES of these chemicals with effects unknown. How does it get into us? Inhalation, ingestion, and through skin contact. And while the levels we are exposed to may be low, research is showing that even low level exposure can have adverse health effects. From Medical Xpress:

Potentially harmful chemicals widespread in household dust

Household dust exposes people to a wide range of toxic chemicals from everyday products, according to a study led by researchers at Milken Institute School of Public Health at the George Washington University. The multi-institutional team conducted a first-of-a-kind meta-analysis, compiling data from dust samples collected throughout the United States to identify the top ten toxic chemicals commonly found in dust. They found that DEHP, a chemical belonging to a hazardous class called phthalates, was number one on that list. In addition, the researchers found that phthalates overall were found at the highest levels in dust followed by phenols and flame retardant chemicals....."The findings suggest that people, and especially children, are exposed on a daily basis to multiple chemicals in dust that are linked to serious health problems." ...continue reading "What’s In Your Household Dust?"

It has long been known that laser pointers can be damaging to the eyes, but apparently this is not widely known. Injuries to the eyes (retinal injuries) causing irreversible vision loss are rapidly increasing from them, especially among children. Injuries to the eye happen when a person stares directly into the laser pointer, or even into the reflection in a mirror. This can inadvertently happen among children, for example when playing games such as laser tag.

A laser pointer is a small handheld device that contains a small diode laser that emits a very narrow beam of light, used to highlight something of interest.during presentations. They are also inappropriately used as toys for some children. The researchers point out that "green laser pointers are becoming increasingly more popular and abundantly available, which is concerning because experiments reveal that green laser pointers (490–575 nm) are more harmful to the retina compared with red laser pointers (630–750 nm)". From Medscape:

Laser Pointers Can Cause Irreversible Vision Loss for Kids

Used incorrectly, laser pointers can damage the retina of the eye and may cause some irreversible vision loss, according to researchers who treated four boys for these injuries. Doctors, teachers and parents should be aware that this can happen, and limit children's use of laser pointers, the authors write.

The authors report on two 12-year-olds, one nine-year-old and one 16-year-old who came to a medical center with central vision loss and "blind spots" within hours to days after looking into or playing with a green or red laser pointer. In one case, the boy looked at the reflection of a laser pointer in a mirror. Two others simply pointed the lasers at themselves, and the fourth was engaged in a "laser war" with a friend.

The researchers report in Pediatrics September 1st that three of the boys had potentially irreversible, although relatively mild, vision loss. One boy's vision continued to worsen two weeks after the injury and eventually decreased to 20/40 best corrected visual acuity in both eyes, which is at or close to the limit for obtaining a driver's license in most U.S. states.

He advises parents to be careful about where they buy laser pointers, as some retailers may not list the power rating or may list it incorrectly, and to limit use for kids under 14. Most consumer laser pointers fall under class II or class IIIA level of safety according to the American National Standard Institute, with a power output of five milliwatts or less. But class 3B or class 4 level lasers may emit up to 500 milliwatts or more and these lasers may cause immediate eye hazard when viewed directly, Almeida and his coauthors write.

Retinal tissue in the back of the eye leads to the brain, and it has no ability to regenerate after tissue loss, Almeida said.

Over the years I have read about some oils, especially lavender and tea tree oils,  as having hormone altering (endocrine disrupting) effects when used over prolonged periods of time or when someone is "chronically exposed". Especially worrisome was the possible estrogenic effects of lavender oils in shampoos, lotions, and soaps on developing children - especially boys (prolonged use leading to the development of breasts in some boys!). I just read a recently published journal study (with very interesting comments at the end), and an article in WebMD about this same topic. The condition of early breast development is called prepubertal gynecomastia in boys and thelarche in girls.

As you can imagine, the industry (Australian Tea Tree Industry Association and Research Institute for Fragrance Materials Inc) calls such research  "poor science". Of course industry sponsored "research" never ever finds any problems (because any "problems" would impact the big $$ from the sale of those products). In fact, I would be skeptical of any industry sponsored research in this area - it is not truly independent, unbiased research if they "have to" and "want to" find no problems. So when you do read industry research, also read the rebuttals by independent scientists and doctors.

Bottom line: No matter the age, avoid prolonged use of lavender and tea tree oil in personal care products, including "aromatherapy" -  especially important for children and pregnant women. The good news is that the development of breasts in young children is reversible when use of the product is stopped. But better to avoid such products (including Agua de Violetas) on children in the first place. Instead use unscented personal care products.

From WebMD:  Are Tea Tree and Lavender Oils Safe for Kids?

Tea tree and lavender essential oils are popular ingredients in personal care and household products, including many aimed at children. But can the ingredients, often promoted as “natural” alternatives, trigger abnormal breast growth in boys and girls? A few small studies suggest that frequently using lotions, shampoos, styling gels, and even a certain cologne containing lavender and tea tree oils may cause breast growth in boys, also known as gynecomastia, along with breast growth in girls as young as 4 or 5

Other studies have not reached the same conclusions, and the cases appear to be rare. In addition, scientific research into most natural products is scant. The FDA doesn’t oversee essential oils unless they are intended for use in a drug, making it challenging to know how safe and effective these products are....Lavender and tea tree oils are among the most commonly used essential oils used. Although research is inconclusive, lavender is often used for aromatherapy and calming lotions, while tea tree oil is promoted for acne, nail fungus, and other skin conditions

...continue reading "Avoid Lavender and Tea Tree Oils In Personal Care Products?"

Yikes! Another study showing effects from antibiotic use - this time a higher incidence of food allergies in children who took antibiotics in the first year of life. Especially multiple courses of antibiotics, with the strongest association among children receiving cephalosporin and sulfonamide antibiotics. Antibiotics can be life-saving, but there can also be unintended consequences.

As the researchers wrote: "Changes in the composition, richness, and abundance of microbiota that colonize the human gut during infancy has been theorized to play a role in development in atopic disease, including food allergen sensitization. " And what changes the gut microbes? Antibiotics. Other research suggests that alterations in microbes due to childhood antibiotic use may increase the risk of Crohn's disease, obesity, and asthma. From Science Daily:

Young children's antibiotic exposure associated with higher food allergy risk

Antibiotic treatment within the first year of life may wipe out more than an unwanted infection: exposure to the drugs is associated with an increase in food allergy diagnosis, new research from the University of South Carolina suggests.

Analyzing South Carolina Medicaid administrative data from 2007 to 2009, researchers from the College of Pharmacy, School of Medicine and Arnold School of Public Health identified 1,504 cases of children with food allergies and 5,995 controls without food allergies, adjusting for birth month and year, sex and race/ethnicity. Applying conditional logistic regression and adjusting for factors including birth, breastfeeding, asthma, eczema, maternal age and urban residence, the researchers found that children prescribed antibiotics within the first year of life were 1.21 times more likely to be diagnosed with food allergy than children who hadn't received an antibiotic prescription.

The association between antibiotic prescription and development of food allergy was statistically significant, and the odds of a food allergy diagnosis increased with the number of antibiotic prescriptions a child received, growing from 1.31 times greater risk with three prescriptions to 1.43 times with four prescriptions and 1.64 times with five or more prescriptions. The interdisciplinary research team, led by Bryan Love, Pharm.D., found the strongest association between children who were prescribed cephalosporin and sulfonamide antibiotics, which are broad-spectrum therapies (adjusted OR 1.50 and 1.54, respectively), compared with narrower spectrum agents such as penicillins and macrolides. .

This research builds upon previous studies finding that normal gut flora is critical for developing the body's tolerance to foreign proteins such as food. Antibiotics are known to alter the composition of gut flora, and U.S. children ages three months to three years are prescribed 2.2 antimicrobial prescriptions per year on average, according to the literature. The study's results suggest a potential link between the rise in antibiotic prescriptions for young children and the rise in diagnosis of food allergies in children.

Yes! Treating young children who have peanut allergies with doses of peanut protein (oral immunotherapy or OIT) for one month works in treating the peanut allergies in the overwhelming majority of young children in an important study. Several studies have now shown that early exposure to nuts is important for prevention of nut allergies, and in this study the researchers showed that both lower and higher dose oral immunotherapy works in treating nut allergies in young children (9 to 36 months of age). Note that this is a paradigm change - before this the thinking was avoid, avoid, avoid for the child to not get or to not worsen the allergy (whether nuts or animals), but now it's early exposure is good in preventing and treating allergies. From Futurity:

Can therapy before 3 wipe out a peanut allergy?

Preschool children with a peanut allergy were able to start eating peanuts after taking part in oral immunotherapy, a new study shows. The findings confirm and extend previous results that show oral immunotherapy (OIT) can protect children from potentially life-threatening anaphylaxis caused by peanut exposure.

The phase two clinical trial results, published online in the Journal of Allergy and Clinical Immunology, show that one month after completing the OIT protocol, almost 80 percent of trial participants achieved “sustained unresponsiveness,” the highest rate yet reported.

“These findings, if confirmed in larger studies, could transform the care of peanut-allergic children early in life,” says Brian P. Vickery, lead investigator of the trial and assistant professor of pediatrics at the University of North Carolina at Chapel Hill. Approximately three million people in the United States report having allergies to peanuts and tree nuts. According to a study released in 2013 by the Centers for Disease Control and Prevention, food allergies among children increased approximately 50 percent between 1997 and 2011.

The initial allergic reaction to peanuts commonly occurs within the first year or two of life, and the condition persists in 80 percent of affected patients, placing them at life-long risk of anaphylaxis. Based on other studies suggesting that peanut allergies strengthen over time, researchers enrolled 40 peanut-allergic children aged 9 to 36 months in the trial, the first study to specifically target children under the age of three.

Children were randomly assigned to high-dose peanut OIT with a target daily dose of 3,000 milligrams of peanut protein or a low-dose regimen with a target dose of 300 milligrams. The trial was double-blinded. Participants took 3,000 mg of study protein, but for the low-dose group, 2,700 mg of placebo was added to the OIT medication. As in previous studies, nearly all participants experienced some side effects, most of which were mild and required little or no treatment.

After receiving OIT for 29 months on average, participants abstained from peanut exposure for four weeks before undergoing a final peanut challenge—where participants ingest a small amount of peanut in a controlled setting. If the challenge is successful, then doctors reintroduce normal amounts of peanuts—such as in a peanut butter and jelly sandwich—into the diets of participants. After the four-week period, nearly 80 percent of children in both the high- and low-dose groups consumed peanut with no allergic response and achieved sustained unresponsiveness.

The OIT-treated children were compared with a matched control group of 154 peanut-allergic children who avoided peanut. The OIT-treated children experienced beneficial changes in their immune responses to peanut and were 19 times more likely to successfully incorporate peanut into their diets.