True food allergies are based on exposure to a specific protein component of a food. The immune system incorrectly perceives the protein as a threat and produces antibodies in response. With repeated exposure, cells release histamine and other biochemicals in response to the allergenic food. It is these chemicals that cause the allergy symptoms. True food allergies are estimated to affect less than 2 percent of adults and 4 to 8 percent of young children and infants.

Food sensitivities are much more common, although estimates vary. Sensitivities are abnormal reactions to food or food components that do not involve the immune system, but involve the body as a whole. There are three types of food sensitivities:

1. A metabolic food disorder occurs when a person is genetically unable to properly or fully metabolize a food component. This includes lactose intolerance (inability to metabolize lactose), which is different from dairy allergies. A dairy allergy can be treated successfully with AAE whereas a true lactose intolerance cannot be treated. However, it is common for people with reactions to dairy to be misdiagnosed as lactose intolerant when the condition is actually a sensitivity.

Another example of a metabolic food disorder is favism (genetic deficiency causing a sensitivity to a chemical in fava beans.

2. Food idiosyncrasy is another form of sensitivity with an abnormal response to a food or food component, but the mechanism for the response is unknown. The symptoms can resemble those of an allergy and can be either severe or mild. Sulfite-induced asthma is one example and causes asthmatic reactions in 1.7 percent of all asthmatics.

3. An anaphylactoid response is a type of reaction that elicits the same release of histamine as a true food allergy, but it does not involve the immune system. The specific substance that causes this reaction has not yet been identified. The response is not the same as anaphylaxis.

• Approximately one in five or more than 50 million (53,980,772) Americans suffer from allergic diseases.
• An estimated 37,786,541 Americans have a pollen allergy.
• Between six and seven million adults in the US have a food allergy.
• Roughly 20 million Americans have asthma -- three times as many as 25 years ago. One in eight children suffer from the disease.
• It is estimated that 12,000,000 American have food allergies.
• In 2002, approximately 14 million office visits to health care providers were attributed to allergic rhinitis.
• Allergies are the 6th leading cause of chronic disease in the United States, costing the health care system $18 billion annually.
• Chronic sinusitis is the most commonly reported chronic disease, affecting 16.3% of people (nearly 32 million) in the United States in 1997.
• It was estimated in 1998 that increased absenteeism and reduced productivity due to allergies cost U.S. companies more than $250 million.
• The estimated overall costs of allergic rhinitis in the United States in 1996 totaled $6 billion.
• The Cincinnati Children's Hospital states that not only has the number of children suffering from allergies increased, so has the severity of the allergic reactions.
• Over 6 million people in Canada have allergies.
• An estimated 4,182,998 Canadians suffer from pollen allergies.
• 12% of Canadian children are affected by asthma and it continues to be a major cause of hospitalization in Canada.
• In 1993, over $12 billion was spent on asthma.