Allergies make more and more people miserable every year. According to the National Institutes of Health, hay fever and other allergic diseases have increased by 200 to 300 percent over the past four decades. In fact, the rate of hay fever went from 3 percent in 1970 to 22 percent in 2006, and the rate of allergic reactivity on blood tests went from 20 percent in 1980 to 43 percent in 2006. The rate of peanut allergies among U.S. children tripled between 1990 and 2006, and over half of today’s Americans will experience an allergy to something during their lifetimes. Worldwide, about a billion people now suffer from allergic diseases. Before the Industrial Revolution, allergies were so rare that there is virtually no mention of them in any of the old medical texts.
The truth about allergies and climate change.
What many people don't know is that climate change is a major driver of the allergy epidemic. And more important than rising temperatures are the environmental conditions that create global warming. For example, an ongoing study of U.S. pollen levels by scientists from Rutgers University finds a steady increase in pollen production during this century and anticipates a near tripling of pollen levels from 2001 to 2040. Increasing pollen has less to do with rising temperatures and more to do with the pollution that is causing climate change. A report published last year by the National Institutes of Health attributes greater pollen to higher atmospheric carbon dioxide—the result of industrial and automotive pollution.
What most people don't know about pollen.
Pollen grains are actually toxic. They contain an enzyme that damages the lining of the nose and lungs, which then encourages allergic reactions. Pollution not only increases the pollen load, but it makes pollen more allergenic, causing grass pollen, for example, to express more of its allergy-inducing proteins. So polluted air damages our respiratory tissues and also makes the environment in which we live more likely to induce allergy. The effects of this cascade far beyond the symptoms of hay fever: Children exposed to heavy traffic have an increased risk of developing pollen allergy. Pollen allergy, in turn, impairs their school performance and sleep. Among adults, pollen allergy impedes driving skills and productivity at work. Scientists in the Netherlands found that pollen allergy impairs the operation of a motor vehicle to the same extent as drinking two cocktails. A study of U.S. veterans showed that pollen allergy slows response times and processing speed to the same extent as taking a sedative drug. The extremely high social cost of the allergy epidemic has yet to be calculated.
Other factors driving the allergy epidemic.
Three major factors, in addition to outdoor air pollution, drive the allergy epidemic. Unlike rising CO2 levels, each of these can be changed when individuals make informed personal choices: First, the indoor environment, where most of us spend 90 percent of our time. Second, the internal environment, the microbes growing in our bodies. And lastly, the food we eat. There are dozens of specific examples of how these three factors drive allergies, but here are three:
Formaldehyde, released into the air in bedrooms, kitchens, and living rooms from glued wood products, furnishings, and smoke, is both a potent irritant and allergen. Australian scientists found a direct correlation between levels of formaldehyde in home air and the likelihood that children growing up in those homes would develop allergies to common inhalants, like pollen and dust. Formaldehyde levels in homes have been steadily increasing, in parallel with the increase in allergy.
Triclosan, an antibacterial chemical widely used in personal care products and cleaning solutions, can be found in the nasal secretions of half of the U.S. population. Exposure to triclosan alters the bacteria living in our bodies and increases the likelihood that children will develop asthma or hay fever. In laboratory animals, triclosan exposure increases susceptibility to developing a peanut allergy.
3. Fast food.
The International Study of Asthma and Allergies in Children found that eating fast food three or more times a week increases the risk of allergic diseases in children and adolescents, whereas consumption of fruit at least three times a week decreases the risk. The reason: Fruit contains protective nutrients called flavonoids that are rarely found in commercial fast food.
No single factor is responsible for the explosive increase in allergies. They act in synergy to produce a perfect storm, with a drastic effect on global health.
Why a toxic environment creates inherited allergies.
Recent research is especially alarming, as it shows that these environmental factors causing allergies also alter the function of human genes. These alterations, technically called epigenetic modifications, can be transmitted from mother to child for generations. The allergies we create today may affect our descendants and change human health for hundreds of years to come. We are already seeing this effect in the well-known familial clustering of allergic diseases, in which maternal allergy dominates.
Suppressing symptoms of allergy with drugs is not the solution. The most commonly used drugs, antihistamines, can cause a long-term decline in cognitive function, a side effect that I first described five years ago. Importantly, medication does not prevent the epigenetic effects of the allergy epidemic. Allergy can only be reversed by dealing with the fundamental environmental cause and reversing toxicity in the three environments we inhabit: outdoors, indoors, and internal.