Why is allergic disease increasing?
There are two main theories. One blames our increasing immune system sensitivity to the many synthetic chemicals in today’s society. Another theory, known as the “hygiene hypothesis,” states that the human immune system is becoming more reactive to allergens because of modern hygiene and health care. Our immune system is designed to fight off viruses, bacteria, parasites and other microbes. However, with modern hygiene, sanitation, vaccines, antibiotics and health care, our immune system does not have many invaders to fight off, and so its attention and energy are re-directed to normally harmless foreign substances.