A study released in July in the journal JAMA Internal Medicine claimed that a group of asthma patients that researchers studied in Pennsylvania were more likely to have asthma attacks if they lived near fracking developments. The researchers looked at data from over 35,000 patients that attended a particular clinic in Pennsylvania from 2005 to 2012. Fracking, which is a method for collecting natural gas, is a politically contentious exercise that has been deemed dangerous on a number of counts. Many of these have been debunked, but the issue remains controversial.
In this particular study, run by a group at the Johns Hopkins Bloomberg School of Public Health, researchers found that asthma patients’ risk for experiencing an asthma attack increased four fold if their residence was in close proximity to where fracking took place. Further, the group looked to see if this association between asthma attacks and fracking depended on the seriousness of a patient’s disease. They therefore classified asthma into mild, moderate, and severe when analyzing their data.
Mild asthma was defined as that which only required medication. Moderate asthma, on the other hand, required a visit to the emergency room. Severe asthma was characterized as asthma that required actual hospitalization. The scientists found that fracking was correlated with increased risk for asthma attacks in all three categories of asthma.
The researchers also looked at the different phases of fracking to see if certain parts of the process may be more detrimental than others. They broke the process up into well development, which includes preparation, drilling, stimulation, and fracturing, and production. They found that all of the phases were associated with increased risk for asthma attacks.
Barbara Gottlieb, who is a program director for Physicians for Social Responsibility, a group that supports a ban on fracking, claims that living near fracking is similar to having an industrial facility in your yard. She also says that there are three different mechanisms by which fracking can lead to asthma attacks. First, she says that an ozone on the ground can be formed by the mixing of chemicals at fracking sites, which leads to asthma. Second, the natural gas, or methane, that can leak out at fracking cites can make asthma worse and at the same time speed up climate change, which may enhance the ozone on the ground. Finally, Gottlieb says that fracking sites usually have more industrial activity around them, which is accompanied by asthma-aggravating factors like transportation.
The study was only a descriptive study showing correlation, so there is no way to determine whether the fracking actually caused an increase in asthma attacks. It is certainly possible that some other factor could be attributed to the observation of increased proximity to fracking being associated with asthma attacks. The study did not explore whether the incidence of asthma attacks was any different before fracking began in this area. Further research that could clarify that issue would help us understand whether the fracking itself was likely to have contributed to asthma attacks. Such information is important for understanding if there is a true relationship between fracking and asthma. If it is determined that fracking does in fact cause or exacerbate asthma symptoms, then it will be important to figure out exactly how fracking impacts the respiratory and immune systems so that steps can be taken to reduce the risk to those living near fracking sites.
A new study has reported that children who suck their thumbs or bite their nails may be at a lower risk for developing allergies than those kids who keep their fingers out of their mouths. This finding is quite intuitive when you consider the hygiene hypothesis. According to the hypothesis, allergies have been occurring in higher frequency in recent decades because children are raised in cleaner environments than ever before. Because of their lack of exposure to germs, their immune systems do not learn to recognize innocuous environment material and therefore overreacts to it later in life, misinterpreting the material for something life threatening.
Those who support the hygiene hypothesis believe that other allergic diseases, such as asthma, eczema, and hay fever may all result from this increased environmental sterility early in life. However, this study did not find a relationship between thumb sucking or nail biting and these other allergic diseases. Nonetheless, other research has pointed to a role of allergens in staving off these allergic diseases. Specifically, research has shown that when parents suck babies’ pacifiers before putting them in their babies’ mouth, those babies develop asthma and eczema at a lower rate than those who do not do this “cleaning” practice. The idea behind this effect is that parents pass microbes from their adult mouths to their babies, thereby introducing substances to their systems that they would not otherwise experience at that age.
The specific results of this study were that kids who sucked their thumbs or bit their nails were less likely to test positive for certain allergies when they underwent skin prick tests. The study, which tracked 1000 people who were born in 1972 or 1973 over 3 decades, collected information on thumb sucking and nail biting habits when the children were 5, 7, 9, and 11 years of age. They conducted the skin prick allergy test when the kids were 13. Whereas 49% of kids who did not engage in either of the relevant habits tested positive in response to common allergens, only 38% of those who regularly put their fingers in their mouth tested positive. Of those who both sucked their thumbs and bit their nails, only 31% tested positive. The specific allergies that were tested included dog dander, cat dander, dust mites, and grass.
When these children grew up and were tested at age 32, the protective effect of thumb sucking and nail biting still appeared to be there. Though those who engaged in both habits did not experience allergies less frequently than those who engaged in just one, those who had sucked their thumb or bitten their nails were still less likely to test positive for allergies than those who had not done either. These effects held up even when researchers controlled for other variables such as gender, family history of allergies, owning a pet, parental smoking, and breastfeeding.
Though these findings fit nicely with the hygiene hypothesis, they do not prove that there is a causal relationship between thumb sucking or nail biting and allergies. Researchers therefore emphasize that it would be too hasty to start to recommend that children suck their thumbs or bite their nails as a way to protect against developing allergies. Instead, further research will help clarify the relationship between these habits and allergies specifically, and the potential role of early exposure to “germs” and other substances in allergy development.
It is perhaps not surprising that allergies and allergic diseases can have a negative impact on quality of life. Patients with these conditions can be chronically nagged with symptoms that in addition to causing discomfort, can also minimize productivity and prevent the ability to engage in certain activities. However, studies are starting to show that allergies may be specifically linked to depression.
The Utah Department of Health has just released the details of a study into a link between depression and the allergic condition, asthma. According to the Utah Asthma Program, more than one third of the adults with asthma living in Utah also have depression. Given that this rate of depression is higher than it is for the general population, researchers believe that there may be an association between asthma and depression.
Those with allergies are not only at increased risk for depression, but the severity of asthma predicts the likelihood of depression, adding support for the link between the conditions. The Utah study showed that people who suffered asthma symptoms on more days also had a higher rate of depression than those who suffered asthma symptoms on fewer days. The study reported that overall, 44% of adolescents who had had an asthma attack in the past year also said that they felt sad or depressed more times than not.
The Utah group speculates that asthma may cause depression because of the adverse effects it has on everyday life. For instance, those with asthma often report feeling out of control. Indeed, the Utah study showed that those with allergies who missed work or school were more likely to be depressed. Allergy patients also often suffer from anxiety related to whether they will endure an asthma attack. Asthma attacks themselves can also be highly anxiety provoking because they can make it very difficult to breathe.
Asthma is not the only allergic disease associated with depression. It is also seen in patients with eczema. Approximately 12% of children suffer from the allergic disease eczema. The disease often resolves by adolescence, but over 7% of adults still suffer from eczema, with around 1.6 million people suffering from a severe form of the disease. In this population, depression and other emotional and mental health disturbances frequently occur.
Whether allergic diseases actually cause depression is still not clear. The Utah groups study demonstrated an association between the two, and the researchers suggested reasons why allergic disease may cause depression. However, other researchers have suggested that depression can actually exacerbate allergic diseases. For instance, studies have shown that when a caregiver has depression, a child with asthma will often endure worsening symptoms.
Scientists at the University of Texas, Dallas and the University of Buffalo have been granted money from the National Institutes on Health to explore this link. They are specifically interested in whether treating a depressed caregiver could help a child’s asthma symptoms. The team will study 200 families recruited through the Women and Children’s Hospital of Buffalo and Dallas’ UT Southwestern Medical Center.
Researchers who are helping to illuminate the links between depression and allergic diseases advise that it may be best for doctors of those with allergic diseases to screen patients for depression. Because having allergies and depression can harm health more than having either condition alone, it is important for health care providers to reduce the likelihood that patients suffer from both types of disease. Given that pollen is peaking at this time of year, both patients and doctors should be aware that allergy symptoms may be exacerbated and that this may be a time when allergy sufferers are particularly vulnerable to depression.
More than 300 million people suffer from asthma. Though many people with the disease are able to control symptoms and disease progression, many others struggle to manage the disease. For some, the struggle is simply in figuring out the best drugs and doses to use. Others, though, seem unable to control their asthma with any of the drugs that are currently available on the market.
The London-based pharmaceutical company, AstraZeneca has developed a new drug for asthma that is showing promising clinical results for those who have been unable to control their asthma with other drugs. The company just released data on phase III studies on this respiratory drug candidate, named benralizumab. The newest studies aimed to evaluate whether the drug is effective in minimizing asthma in patients, and whether the drug is safe.
Benralizumab has been successful in reducing the frequency of asthma attacks in this population of severe asthma sufferers. Specifically, those who used the drug experienced fewer asthma attacks in the course of a year than did those who did not use the drug. Patients also tended to tolerate the drug well, with few or no adverse side effects. More details on safety outcomes will be released in coming months. However, there do not appear to be any red flags in terms of the drugs safety at this time.
To date, the clinical trials on benralizumab have included around 2500 people, ages 12 and up, who suffer from severe asthma and who have what is known as eosinophilic inflammation. The drug, which is an injection therapy, is intended for people who have not been able to control their asthma with conventional asthma medications, including inhalers and pills. Benralizumab is not the first injectable drug that has been developed for severe asthma. Other companies, including GlaxoSmithKline and Teva Pharmaceutical Industries produce drugs that are similar to benralizumab in a number of ways.
The impact of benralizumab has not been compared to that of the other injectable drugs yet. So far, AstraZeneca’s drug has only been tested against placebos and other types of asthma drugs that are not injected. However, whereas the injectable drugs created by GlaxoSmithKline and Teva Pharmaceutical Industries act on a protein that activates eosinophils, the cells that are believed to cause asthma, benralizumab acts directly on these cells. Given that benralizumab works via a more direct mechanism than other injectable drugs, it may turn out to be more effective. Another potential benefit of benralizumab is convenience and ease of use. Unlike other injectables, benralizumab comes in a prefilled syringe and thus does not require the additional preparation that many injectable drugs do.
About 1 in 10 asthma sufferers has severe asthma, totaling approximately 30 million people worldwide. The drug could therefore have a significant global impact on asthma. Additionally, AstraZeneca plans to test the drug in other phase III trials for use in patients with severe chronic obstructive pulmonary disease, potentially expanding the impact of the drug. AstraZeneca plans to submit the drug for regulatory approval in both the United States and European Union by the end of 2016.
Though it is not necessarily intuitive, there is a significant amount of research that shows that the time of year when you are born can impact a number of factors in your life, including your eventual height, whether you develop diseases, and how long you live. In recent years, there has been speculation that your birth season may predict your chances of developing allergic diseases such as asthma.
In 2010, following observations that children born in the fall or winter suffer from allergic symptoms like wheezing and eczema at higher rates than those born in spring or winter, scientists in Finland studied a group of almost 6000 children whose ages ranged from 3 to 9. Of the 6000 children, 1000 had been tested for food allergies by the age of 4. When the researchers dove deeper into the details of the allergies of these children, they found that birth season predicted a number of allergic factors. For instance, 11% of children whose 11th week of gestation was during April or May suffered from food allergies during their baby or toddler years. Far fewer children whose 11th week of gestation occurred at other times had food allergies at this young age.
Similarly, the researchers noticed that specific foods seemed to affect children differently depending on when children were born. For instance, some foods that affected only 5% of those born in June or July affected almost twice as many children (9.5%) born in October or November. The researchers believe that pollen may be the culprit for this pattern of findings, as pollen levels in the air would have peaked in April and May, during a critical time in these children’s fetal development when they are able to start producing antibodies. The scientists note that by 24 weeks of gestation, babies are able to produce antibodies to specific allergens. The study was published in the Journal of Epidemiology and Community Health.
Now, there is new research that confirms and expands upon these 2010 findings. A study conducted by researchers from the University of Southampton and just released in the medical journal Allergy provides new evidence that being born at a certain time of year increases your risk for suffering from allergies and helps clarify why this may be the case. The scientists found that people who were born in the autumn months were more likely to develop the allergic condition eczema. When they looked at the DNA of these people and compared it to the DNA of people born in other seasons, they found that the DNA of those born in the fall underwent specific epigenetic changes not see in those born in winter, spring, or summer.
Epigenetic changes are changes that occur to genetic material as a result of environmental factors. In the case of those born in autumn months, the epigenetic change was seen to be specifically a process called DNA methylation, which can change gene expression in a way that allows people to produce different types of proteins. For those born in the fall, who have these specific types of epigenetic changes, it may be the case that the altered gene expression they experience modifies the way their immune systems responds to allergens.
The researchers suggest that there may be certain factors that lead to the epigenetic changes seen in those born in autumn and that further research is needed to understand how such factors, which may include the food that is in season, the temperature, or specific sunlight levels, may make the season one is born in predictive of the development of certain conditions.
Asthma has been reported as the primary cause of chronic disease and disability in children. Because asthma can be life threatening, effective drugs and inhalers that are used to combat asthma symptoms can be critical to survival. However, some doctors are arguing that asthma is being over-diagnosed in children and that too many children are now using drugs whose effects should not be taken lightly.
Though the drugs used to treat asthma can save the life of someone enduring an asthma attack, they also have non-trivial side effects. The drugs can suppress growth and also suppress immune activity in the airways, which can increase the risk for respiratory infections. In addition, the drugs tend to be costly. According to some doctors, wheezing, which is a hallmark of asthma, is not always accurately identified. It is important that doctors recognize normal respiration in children if they are to distinguish asthma from other conditions or from healthy respiratory activity.
To remedy the situation, doctors are suggesting more stringent diagnosis protocols.
Rather than making a subjective judgment based on symptoms or a few clinical features, these doctors argue that an objective test must be employed before an asthma diagnosis is made. Airflow obstruction measurements and airway inflammation are two tests that these doctors believe are essential for an asthma diagnosis. Some argue that more invasive tests may be warranted if there is any doubt that a patient is suffering from asthma. For instance, blood tests and testing nitrogen oxide levels can help doctors be more confident of their asthma diagnosis.
In light of the problem of over-diagnosis of asthma, doctors and scientists are also pushing for more funding into asthma and allergy research, with the hopes that a more definitive asthma identification test will be created. Unlike some diseases, asthma does not represent one single condition but instead many, and it has different triggers and causes for different people and at different ages. Given its complexity, there has before been fear that asthma is under-diagnosed, which may be a contributing factor to over-diagnosis today.
Another issue with the overuse of asthma medications is that children often outgrow asthma. Many people continue taking their medications, assuming that they need them. However, rather than continue using unneeded drugs and subjecting themselves to side effects and potential complications, the status of patients’ asthma should be regularly monitored and updated. Further, close monitoring will allow doctors to see how patients respond to their medications. If asthma drugs do not seem to benefit a child, then the asthma diagnosis was likely incorrect. Unfortunately, when this is the case, physicians often increase the dose of the drug rather than reconsider the use of the rug. Even if a child does suffer from asthma, finding the right drug and drug dose can be time consuming. Thus, regardless of how confident a physician is in an asthma diagnosis, close monitoring and continual evaluation is warranted.
A new study analyzed this concern over misdiagnosis and found that half a million children that have been diagnosed with asthma do not in fact have the disease. In the study, researchers used a spirometer, which is a device that measures lung function, as well as other allergy tests to analyze the lung function of approximately 650 children, aged 6 to 17 years, that had been diagnosed with asthma. The scientists found that over half of these children did not actually have asthma. Further, only about 16% of these children had been tested with a spirometer prior to their diagnosis.
Respiratory doctors who published their views on over-diagnosis of asthma in children in the Archives of Disease in Childhood said that inhalers have “almost become a fashion accessory.” It is perhaps then not surprising that the Centers for Disease control (CDC) say that 1 in 12 people have asthma in the United States, which amounts to about 25 million people and that this number has grown since 2001. The estimated number of asthma sufferers in the US was only 20 million 15 years ago. However, now that fears of under-diagnosis of asthma have shifted, and awareness is growing as to the potential for over-diagnosis, changes in protocols and research focus should help ensure that appropriate asthma diagnoses are made and that children are provided with only the drugs that will best benefit them.
The significant rise in peanut allergies in recent years has puzzled physicians and scientists. In the past decade, peanut allergies have quadrupled in the United States. The scientific community has started to suspect that doctors’ recommendations to parents, regarding when to feed their children peanuts, could be partly to blame for the rise in peanut allergy incidence.
Doctors used to tell parents to avoid feeding their children foods that are often associated with allergies, such as peanuts, eggs, and fish, until their children were about three years old. The idea behind this protocol was that young immune systems may not yet be ready to deal with these potentially problematic foods. In 2008, however, these recommendations changed when the American Academy of Pediatrics decided that delaying the introduction of these foods may in fact increase the chances that allergies develop.
Last year, a long-term study known as LEAP showing that 5 year olds were 81% less likely to be allergic to peanuts if they ate peanuts products like peanut butter before they were 11 months old was published in the New England Journal of Medicine Last month, another study, known as LEAP-On, was published in the same prestigious medical journal that further supports the idea that exposing kids to peanuts early may actually be an effective way to prevent the development of peanut allergies. In addition, the study demonstrated other positive effects that peanuts may have on health.
As in the previous study, this recent research focused on children with a high risk for developing an allergy to peanuts. They found that kids who ate peanut products from infancy until they were 5 years old could avoid peanuts for a full year without affecting their risk of developing a peanut allergy. There were 550 study participants who were asked not to ingest peanut products for one year, from the age of 5 to the age of 6. Once they were 6, these children were tested for peanut allergies, and 21.5% of those who had always refrained from ingesting peanuts were found to be allergic to them, whereas only 2.4% of those who ate peanuts in their first 5 years of life were now allergic.
Enough exposure early on in life therefore seemed sufficient enough to allow children’s immune systems to recognize peanuts as innocuous in the long-term, even if peanut exposure was not consistent afterward. This new study builds on the previous finding that early peanut exposure reduces the risk of developing peanut allergy by showing that this protection can last even through a subsequent avoidance phase.
Several other problems often seen in children, including stomach bugs, eczema, lower respiratory tract infections, and near-sightedness were also found to be lower in the children who ingested peanut products from infancy to the age of 5. Given the latest findings on the relationship between peanut exposure and the likelihood of developing peanut allergies, as well as the correlation between peanut exposure and other health benefits, the American Academy of Pediatrics are working to develop updated guidelines. For now, pediatricians are told to suggest to parents that children be introduced to peanuts between the ages of 4 and 11 months if the children are at risk for developing peanut allergies.
Another recent study, known as EAT, looked at the ability of early exposure to other foods, such as egg, fish, milk, and wheat to desensitize children to allergies to these foods. Though the study clearly showed that early exposure to egg could reduce rates of the development of egg allergy, the findings for the other foods were less clear. Researchers plan to improve their study designs so that they can clarify the specific impacts of early exposures to problematic foods and determine any differences that may exist in the pattern of allergy development for different foods.
There are a number of reasons why babies may not be able to receive sufficient nutrition from breast milk. To combat the obstacle and ensure that babies are offered proper nutrition easily and early in life, formula was created. Given that breast milk is lacking in certain nutrients, formula provided an opportunity to provide babies with these added nutrients. Indeed, breastfed babies are generally required to take supplements such as vitamin D and iron. In addition, formula creators can formulate the product to address any number of health issues, aiming to provide as many health benefits as possible.
A “hypoallergenic” formula was created by Nestle, which the company claimed provided protection against autoimmune diseases and problematic health issues like asthma. Nestle was granted permission in 2011 by the US Food and Drug Administration (FDA) to market its formula as a product that reduces the risk of developing eczema. However, a new study, published in the British Medical Journal is raising doubts that the formula actually provides the health benefits its creators have been claiming.
Robert Boyle and other authors of the study reviewed information from approximately 19,000 participants in 37 different trials between the years of 1946 and 2015 and concluded that there was little evidence to suggest that formula, or the process that is undertaken to create formula confers any protection against allergy-related conditions or autoimmune disease. To make hypoallergenic formula, cow’s milk is heated to break down proteins in a process called hydrolysis.
Proponents of formula’s health benefits have argued that by breaking up proteins, and thereby making them smaller (into what are known as peptides), the proteins have less power to produce allergic reactions. They claim that with less exposure to allergenic peptides could prevent the sensitization that occurs when allergies develop, thereby reducing the risk of allergies and other autoimmune reactions. As a result of their claims, formula is recommended for infants at increased risk for allergies, asthma, eczema, allergic rhinitis, and even type 1 diabetes.
Immune conditions including allergies and asthma have increased in recent years, particularly among young people, which has increased the incidence of chronic disease. There is much evidence to suggest that dietary exposures during infancy may be associated with the development of some of these conditions. Though it is well established that a proper diet is essential for healthy development and the avoidance of chronic diseases, there is still much to learn in terms of what the ideal diet is for infants and children. The specific nutrients and their optimal doses are still debated by scientists and doctors.
Given the findings of the systematic review and meta analysis conducted by Boyle and his colleagues, some scientists are now urging the FDA to reconsider its recommendations regarding the use of formula and suggest that commercial interests may have interfered with the integrity of the scientific investigation of the health benefits of formula. They also point out that claims made about formula in marketing campaigns could undermine mothers’ motivation to breastfeed, which has been established as the healthiest option for feeding infants.
Scientists from the National Institutes of Health (NIH) have discovered a genetic mutation that causes for a very rare type of allergy - an allergy to vibration. The team of scientists, who were specifically housed at the National Institute of Allergy and Infectious Diseases (NIAID) and the National Human Genome Research Institute (NHGRI) published their findings in the New England Journal of Medicine on February 3rd.
Allergy to vibration, known as vibratory urticaria, causes sufferers to break out in itchy hives or skin rashes on areas of the body that endure vibration. Though the allergy tends to lead to only mild symptoms, for those with this particular allergy, everyday activities, such as exercising, riding in motor vehicles, hand clapping, and using towels can pose serious inconveniences. For some, the allergy to vibration can lead to symptoms unrelated to the skin, such as headaches, blurry vision, and fatigue.
To gain some insight into why and how the immune system reacts to vibration as it does in those with vibratory urticaria, the scientists looked at how key immune cells, called mast cells, reacted to vibration. They looked at these cells in a family with multiple generations of vibration allergy sufferers, as well as in other people who did not suffer from the allergy and were not related to anyone with the allergy.
Researchers found that people with vibratory urticaria had higher levels of substances called histamine and tryptase in their blood than those without the allergy. These substances are normally found in mast cells, so the rise of these substances in the blood indicated that mast cells released their contents in response to vibration. In those without vibratory urticaria, these rises in histamine and typtase were not observed in the blood. Vibrations therefore initiated a specific immune response in those allergic to vibrations and not in those without the allergy.
The researchers realized that the symptoms in the family they were studying resembled those of a family described in 1981 by scientists at Yale. To test for a genetic contributor to vibratory urticaria, researchers took DNA samples from both families and identified a mutation in a single gene, the ADGRE2 gene. The mutated form of the gene was present in all family members who were allergic to vibration and in none of those who were not. The mutation was also not found in a database of DNA of 1000 other individuals who did not have vibratory urticaria.
Researchers were therefore convinced that the genetic mutation of ADGRE2 contributes to allergic reactions to vibrations. Further studies have shown how the gene leads to allergy symptoms in response to vibrations. The ADGRE2 gene produces an ADGRE2 protein that is present on immune cells. The protein has two portions that are normally close together and relatively stable. In those with vibratory urticaria, the two subunits of the ADGRE2 protein are less stable and separate more easily in response to vibration. When these cells separate, it signals to the immune system that an immune response is needed. At that point, mast cells are activated, and they release their contents.
These findings by NIH researchers clarify details of immune system responses generally and allergic reactions specifically. Researchers hope to find out how the subunits of the ADGRE2 protein act once vibrations are over because that information could help them better understand the allergy to vibration and potentially treat it. They also plan to study more families with vibratory urticaria to develop a more comprehensive view of this intriguing allergy.
Vitamin D, also known as the sunshine vitamin, has long been linked to allergies. Studies have shown that children who live farther from the equator are more likely to develop allergies and suffer higher rates of hospital admissions due to allergic reactions. From November through February, it is thought that people in the north (at a latitude above 35°) cannot synthesize vitamin D because they are not sufficiently exposed to sun.
Children and adolescents with lower levels of vitamin D in their blood are more sensitive to allergens than those with higher vitamin D levels. In 2012, a study published in the Journal of Pediatrics demonstrated that infants with vitamin D deficiency are at higher risk for allergies and eczema than those with sufficient levels of the vitamin. Further, the severity of allergy in infants was shown to be linked to the severity of vitamin D deficiency.
Now, researchers at the Mount Sinai School of Medicine have discovered that one’s exposure to vitamin D may impact their likelihood of developing allergies even before they are born. The recent study, published in The Journal of Allergy and Clinical Immunology on February 11th, showed that women who eat foods that are rich in vitamin D during pregnancy are less likely to have children who will develop allergies. This finding is consistent with previous reports that maternal vitamin D levels are related to the likelihood that children will wheeze at the age of 3.
This new study examined 1,248 American women and their children from the first trimester until children were approximately 7 years old. Children with a reduced risk for developing allergies had mothers who had consumed higher amounts of vitamin D. Vitamin D can be found in dairy products including milk and eggs, as well as in other foods such as fish, mushrooms, and cereal. Women who consumed at least the amount of vitamin D that would be found in 8 ounces of milk per day were shown to confer the allergy benefits to their children. These children had a 20% reduced risk of hay fever in their school years.
Vitamin D likely reduces the chance of developing allergies because of its effect on the immune system, which has been demonstrated in a number of ways. Vitamin D has been shown to quickly rid the body of hives and other allergy symptoms. This vitamin is critical to the proper functioning of T-cells, which are a major part of the immune system.
The finding that vitamin D can protect a fetus from eventually developing allergies is a promising discovery in the allergy field. However, it should be noted that vitamin D supplements did not have the same effect as vitamin D found in foods. In other words, pregnant women had to eat foods containing vitamin D to confer the allergy benefit to their children. However, the research linking vitamin D supplements to allergies and asthma has produced a large mix of results.
Whereas some scientists have supported the idea that vitamin D supplements taken by pregnant women can reduce the risk that their children will develop allergies and asthma, others have shown that adults who took vitamin D supplements as infants were in fact more likely to develop allergies than those who did not take the supplements. One study showed that vitamin D supplements were effective in both preventing and treating seasonal allergies, but other studies found that vitamin D supplements had no effect on the likelihood of developing allergies. Scientists therefore believe that further research is needed before we can truly understand the impact of vitamin D supplements on allergies. It may be the case that higher doses of the supplements are needed to achieve the same effect as consumed vitamin D.
For now, it is likely that clinicians will recommend that pregnant women consume vitamin-D rich foods during pregnancy. Not only are the recent data on the protective effect of vitamin D against allergies promising, but vitamin D has a number of other health benefits and is therefore a critical component of our diets.