Reduce Your Allergy Risks

Conventional allergists once thought of allergy as an accident of birth. They believed that if one or both of your parents slipped you some "allergic" genes, it was like drawing the Monopoly card that says, "Go directly to jail." You were doomed by heredity to spend the rest of your life in a kind of  allergic prison.

If your parents didn't give you those genes, you were home free. You got to pass "Go" and collect $200 that you otherwise would have spent on facial tissues.

As the incidence of allergies started rising in the 1970s, that theory crumbled. Genetics alone could no longer explain the spectacular increases in allergic rhinitis, asthma, and other allergic conditions.

Today, researchers believe that in addition to genetics, the environment also plays a critical role in determining who will and who won't develop allergies. Since allergies are strongly associated with the Western lifestyle, researchers have begun to suspect that a multitude of lifestyle factors are involved.

Although scientists haven't yet found all the pieces to the puzzle, their message is empowering. For if allergy is even partly a consequence of making the wrong lifestyle choices, then it should be possible to reduce or even eliminate allergic woes by making the right lifestyle choices. "You can't change an inherited predisposition to allergy, but you can adjust your lifestyle and modify your environment to influence immunity in the right direction," says Andrew Weil, MD, Prevention advisor and founder and director of the Arizon Center For Integrative Medicine and clinical professor of medicine at the University of Arizona. "Allergy is a learned response of the immune system, and anything learned by this system can be unlearned."

Here's a brief description of how genetics, environment, and lifestyle place you at risk for developing allergies.
 

Genetics
Interleukin-4 is one of the key proteins that play an essential role in allergic reactions. It increases production of the IgE antibody, which is what makes you sick. Scientists theorize that high occurrences of a gene that promotes interleukin-4 production may be the reason why African-Americans have higher rates of allergies and asthma.

Studies show that African-Americans have very high levels of interleukin-4, probably because their ancestors needed it to fight off tropical parasites. Since the immune system is not happy unless it has something to fight, it's possible that African-Americans' immune systems have switched targets from harmful parasites to harmless allergens.

Environment
Over and over again, researchers have found that people of similar racial backgrounds have radically different rates of allergy if they live in different environments.

For the most part, the world's "haves" have much greater incidences of allergy than the "have-nots." The pattern holds true in Asia, where the urbanized Japanese are more allergic than the rural Chinese. It also holds true in Africa, where metropolitan residents are more allergic than people living in the countryside.

One of the most telling studies was conducted immediately after East and West Germany were reunified. It found that affluent West Germans were far more allergic than their relatively impoverished East German counterparts. This study blew the lid off the theory that industrial pollution—which was notoriously high in the former East Germany—was responsible for the allergy epidemic."I'm sure their original hypothesis was that they'd find more asthma in East Germany than in West," says Harold Nelson, MD, professor of medicine at the National Jewish Medical and Research Center in Denver. "Everybody wants to blame air pollution for the increase in asthma."

It simply isn't so. Although there's strong evidence that indoor tobacco smoke increases children's risk of developing asthma, there's little proof that such outdoor pollutants as sulfur dioxide, particulate matter, and ozone increase anybody's risk of developing allergies.

There is a strong association, however, between allergies and other environmental factors, such as socioeconomic status, family size, early-childhood infections, and diet. Exactly how these factors combine with heredity to produce allergy is an area that still needs more research.

If you have any doubt that environment is a driving force in allergy, consider what happened in the former East Germany within 10 years of reunification with West Germany. As billions of marks were spent bringing the one-time socialist state into the capitalist fold, living standards in the East rose dramatically. But so, regrettably, did its allergy woes. Today, all of Germany is plagued with shockingly high allergy rates.

Lifestyle
When scientists first identified allergy as a disease of Western living, they thought the explanation was simple: Western homes have more of everything, including indoor pollution, pets, and processed foods.

"We first thought that the increasing prevalence of asthma was related to the decreasing quality of the indoor environment because of increased insulation, warmer homes, tighter homes, more moisture, and all that," Nelson says. "There's no question that indoor air quality of homes has deteriorated with Westernization. Everybody thought that was the whole answer. Then we started seeing situations where it didn't fit."

As proof, Nelson cites European studies showing that infants exposed to dogs or cats at home have only half as many allergies as children coming from petless homes. "That's where the hygiene hypothesis comes in," he says.

The hygiene hypothesis states that our over-sanitized Western lifestyle keeps our immune systems confused, off balance, and unable to distinguish friend from foe. Researchers believe that much of this confusion begins in infancy. Increasing evidence shows that a baby's immature immune system can't develop properly unless it's exposed to such things as the bacteria found in fermented foods. "You want the right stimulus down in your gut when you're an infant," Nelson says. Early exposure to antibiotics, however, seems to create the wrong stimulus by disrupting the balance of friendly and unfriendly bacteria. The result is an increased risk of allergy.

The challenge facing scientists in the 21st century is to figure out just how the over-sanitized Western lifestyle, genetics, and environment combine to create allergy. But since two of these three factors are controllable, there's great hope that one day a life interrupted by allergies will be a thing of the past.