Allergies less common among kids born outside US

Children who move to the United States have a lower risk of allergies than kids born in this country, a new study suggests.

In the study, children who immigrated to the United States were about 44 percent less likely to have an allergy condition — including asthma, eczema, hay fever or food allergies — compared with kids born in the country.

The study is published today (April 29) in the journal JAMA Pediatrics.

Children need to "eat dirt" so to speak. We as parents need to expose our children to the environment around us and let the child's God given immune system get a workout. If you wanted to get stronger or run faster you need to exercise, the same is true for the immune system. Give it a workout and make sure it is functioning at its best. How do you know if it is not? Have them checked by a pediatric chiropractor. (That's me, Dr. Maly)

The findings support the " hygiene hypothesis," which proposes that exposure to germs or infections during early childhood may protect against some allergies, the study authors said.

However, the apparent protection from allergies seen in the study was not permanent. Foreign-born children who lived in the United States for more than 10 years were about three times more likely to develop an allergy compared to foreign-born children who lived in the country for two years or less, the study found.

The findings are in line with what the researchers had observed anecdotally in their own practice: people who immigrate to the United States tend to develop allergies at a later age than those who were born here, said study researcher Dr. Jonathan Silverberg, a dermatologist at St. Luke's-Roosevelt Hospital Center in New York City.

The new findings suggest that allergies may arise differently depending on where a person was born, a topic that needs further study, Silverberg said.

Previous studies had shown that the prevalence of childhood allergies is higher in the United States than in other countries such as Mexico and China. However, few studies had examined the risk of allergies among U.S. immigrants.

The new study was based on information from about 91,800 U.S. children. Parents were asked in a survey in 2007 and 2008 whether a doctor had ever told them that their child had asthma, eczema, hay fever or food allergies.

About 34 percent of children born in the United States had an allergy, compared with about 20 percent of those born outside the country. The link held true regardless of participants' ethnicity, income level or whether they lived in an urban or rural area.

Children born outside the United States were 73 percent less likely to have asthma, 55 percent less likely to have eczema, 66 percent less likely to have hay fever and 20 percent less likely to have a food allergy compared with kids born in the United States.

Children who were born in the United States but whose parents were immigrants also had a reduced risk of allergies.

Foreign-born children who lived in the United States for longer than 10 years were more likely to have eczema or hay fever than those who lived in the country for two years or less.

The new study cannot say why children born in the United States are at greater risk for allergies than those born in other countries.

Silverberg said he suspects that a number of factors, including climate, diet and obesity, play a role in triggering allergies. 

By Rachael Rettner, MyHealthNewsDaily

How We Are Making Our Children Sick part 5 of 6

Dietary Fat Consumption

Chicken nuggets, potato chips, and other fried foods, while convenient for parents, are relegating their children’s immune systems to behave badly. Another factor that has been identified as a contributor to the rise in allergic diseases is the increased consumption of omega-6 fatty acids and the decreased consumption of omega-3 fatty acids. It has been known for many years that individuals with allergic conditions have disproportionately high levels of omega- 6 fatty acids in their blood. Omega-6 fatty acids actually suppress the immune system and promote inflammation, and allergic responses are, by their very nature, inflammatory. Sources of omega-6 fatty acids are corn, cotton, soybean, peanut, safflower, and sunflower. Omega-6 fatty acids are also present in most animal products.

Inversely, omega-3 fatty acids are known to enhance immunity, reduce inflammation, and protect the nervous system. Dietary omega-3 fatty acids have well documented immunological effects. Sources are flax, hemp, walnut, and cold water fatty fish, especially salmon. It is important to note though that the plant sources of omega-3 fatty acids are inadequate for infants and thus offer minimal benefit early in life. One study showed that children who regularly consumed oily fish were 74% less likely to develop asthma. Other studies show that fish oil supplementation is associated with improved asthma symptoms and reduced medication usage. The immune benefits of omega-3 fatty acids are likely greater during the critical stages of early immune development before the allergic responses are established, so it is recommended that women monitor their fatty acid intake during pregnancy and continue to do while nursing. Once the child is old enough there are omega-3 products designed specifically for children.

How We Are Making Our Children Sick part 4 of 6

Vaccination

Most childhood infections are caused by viruses, and thus do not respond to antibiotics, hence the development of our current vaccine program. Infections contracted naturally are ordinarily filtered through a series of immune system defenses. Naturally-contracted viral diseases stimulate a cell-mediated response, and it appears that because of this, early viral infections are protective against allergic diseases. When a vaccine is injected directly into the blood stream, it gains access to all of the major tissues and organs of the body without the body’s normal advantage of a total immune response. This results in only partial immunity, consequently the need for “booster” shots. Vaccines stimulate a humoral response so their contents are never discharged from the body, the way they would be if the disease were naturally contracted, leaving the body in a chronic state of sensitization. In a study of 448 children, 243 had been vaccinated against whooping cough. Of these, 10% had asthma compared to less than 2% of the 205 children in the non-vaccinated group, suggesting that the pertussis vaccination can increase the risk of developing asthma by more than five times.

How We Are Making Our Children Sick part 2 of 6

Hygiene

There are numerous reports that suggest the excessive cleanliness practiced in modern society may be partly responsible for the increased incidence of allergic diseases. Repeated exposure while young to various types of bacteria and spores found in dirt, dust, and animal dander may actually protect against the development of allergies. A molecule known as an endotoxin naturally occurs in the outer membrane of bacteria. When the bacteria die the endotoxin is released into the environment. Children are exposed to these endotoxins by breathing them in, or by ingesting them when they put their hands or other objects into their mouths. The exposure to bacteria, viruses, and endotoxins is essential for the maturation of the immune system; less exposure leads to imbalanced immune responses.

Children’s early exposure to allergens and infections prime their immune systems to resist them later on. Although children in daycare seem to get sick more often than other children do, this is not necessarily a bad thing. These colds and other infections may be giving their immature immune systems a health workout, resulting in a lower incidence of asthma. Children with the highest degree of personal hygiene are the most likely to develop eczema and wheezing between the ages of two and a half and three and a half years. In 2000, a study of 61 infants between the ages of 9–24 months found that the more house dust an infant was exposed to, the less likely that they would suffer allergies.