Global Warming Prolongs Allergy Season

What is Allergy?

The word allergy means “altered working.” It was coined at the beginning of the twentieth century, after dogs inoculated with proteins from other animals had severe reactions when they came into contact with those proteins again.

Allergies are responses mounted by the immune system to a particular food, inhalant, or chemical. In a simplified sense, an allergic reaction is an adverse or inappropriately amplified immune system response to something that many other people find harmless.

Most commonly, an allergic reaction expresses itself as a headache or fatigue, and may include

  • sneezing,
  • watery eyes,
  • nasal congestion.

More severe allergic reactions, such as those to certain nuts, fish, and insect stings are known as anaphylaxis and are characterized by:

  • the swelling of tissue and
  • the inability to breathe.

These reactions may need to be treated as serious medical emergencies. A synthetic epinephrine, a hormone naturally produced by the adrenal gland, may be administered to combat the reaction. People with severe allergies should carry epinephrine pens in case of accidental exposure to the allergen.

According to the National Institute of Allergy and Infectious Diseases (NIAID), people with allergies spend more than $5 billion annually on doctors’ visits, allergy shots, and prescription mediations. Many health conditions are related to allergies, including:

  • acne,
  • asthma,
  • attention deficit disorders,
  • bladder infections, and
  • a host of digestive disorders.

Climate Change and Allergy

Does it feel like those first allergy symptoms are starting earlier? It could be the result of global warming! At a meeting of the American Academy of Allergy, Asthma and Immunology in New Orleans, scientists presented information from a study indicating that climate change may be extending pollen seasons.

According to a team at Genoa University in Italy, pollen seasons, as well as the amount of pollen in the air, progressively increased during a 26 year study in Italy. The study group recorded pollen counts, how long pollen seasons lasted and sensitivity to five different types of pollen in the Bordighera region of Italy from 1981 to 2007 (26 years span).

“By studying a well-defined geographical region, we observed that the progressive increase in the average temperature has prolonged the duration of the pollen seasons of some plants and, consequently, the overall pollen load,” Dr. Walter Canonica, who worked on the study, said in a statement.

Christine Rogers, a research associate in Environmental Science and Engineering at Harvard University agrees. In a recent interview in the Live Science newsletter, she is quoted as saying, “There have been significant increases in allergies and asthma in recent decades which cannot be explained by any change in genetics.”

Rogers reviewed the scientific literature on the change in plant flowering times and airborne pollen concentrations over the last few decades. “Plants are flowering significantly earlier over time and advancing the season by approximately 0.8 days per year,” Rogers said.

Allergic rhinitis, commonly known as hay fever, is a reaction to indoor and outdoor airborne allergens, such as pollen. Longer pollen seasons and high levels of pollen certainly can exacerbate symptoms for people with allergies and for those who previously had minimal symptoms.

The US Center for Disease Control and Prevention estimates that about 25 million Americans suffer from allergies – nearly half of them are children.


“D’adamo Personalized Nutrition”, The e-newsletter for people who Eat Right for Your Type, April 2010.