Although there are numerous studies investigating the prevalence of food allergy in adults, comprehensive, nationwide, population-based studies are still needed on the frequency of food allergy in adults and the risks associated with food allergy. Most reports have incorrectly called food allergy in adults with complaints such as abdominal pain, based on self-reported food allergy symptoms. Also, reliance on patients’ reports of possible food allergy may result in an overestimation of food allergy frequency.

What is the difference between food sensitivity and food allergy?

First of all, it is necessary to know some definitions well. When a blood or skin test is performed against foods, some foods have high IgE values, and there is no symptom after taking foods with this positive test, is called nutrient sensitivity. Food allergy, on the other hand, is a situation where the IgE value is high in the blood or skin test and at the same time, the symptoms occur when this positive food is taken, is called food allergy. A non-IgE food allergy is a situation in which food allergy symptoms occur after taking a food even though the blood or skin test is not positive.

The diagnosis of food allergy is based on both food allergen sensitization and the development of classical allergic symptoms with food ingestion. A high sIgE or a positive skin test to a food is evidence for sensitivity to an allergen, but does not mean that a person has a food allergy unless that person develops IgE-mediated symptoms from eating a particular food. In other words, only a subset of individuals who report food-related reactions are sensitized to these foods, and only a subset of those who are susceptible have true food allergies. For these reasons, there is little data on the true frequency of food allergy (IgE-mediated) in adult populations. However, both self-reported reactions and sensitization can be used as markers for trends in true food allergy frequency.

There is an increase in the frequency of adult self-reported food allergies without an increase in physician diagnosis of food allergy in adults. This discrepancy is alarming and likely indicates an overdiagnosis of food allergy, multiple nutritional and psychosocial consequences, and a consequent negative impact on an individual’s health and quality of life. Patients may be increasingly avoiding foods without seeking medical advice. This could potentially result in social isolation or lead to the development of eating disorders.

What is the Frequency of Food Allergy?

The estimated frequency of food allergy in adults is 3.9% to 8% in infants and children and 6.6% to 10% in adults. Clinically, the incidence of food allergy decreases with age, with the highest incidence in children aged 1 to 5 years (4.2%) and the lowest in those aged 60 years and above (1.3%).

What is the Frequency of Food Sensitivity?

The rate of sensitivity to at least 1 common food allergen among adults is 14.9% in the United States and is quite high. These sensitization rates range from 11% to 24% among Europeans.

In agreement with the reported food allergy, the rate of food sensitivities in the USA is very high, with rates as high as 16.8% reported in 2010. The highest prevalence of food sensitivities is in children aged 1 to 5 years (28%), decreasing gradually with age. These rates are not the food allergy rate, but the food allergy sensitivity rate. In other words, it is the rate of people who report that they have food allergies in blood tests or that they have symptoms when a food is taken. 

Food Allergy and Food Sensitivity is More Common in Who?

Adult self-reported food allergy is more common among adults in women. However, the rate of sensitivity to food allergens is similar in both men and women. Food sensitivities to peanuts, shrimp, and milk are more common in males.

Previous studies have estimated the frequency of food allergy to be different among race-based individuals, with non-Hispanic African Americans in the US the highest risk group. This applies to both adult self-reported food allergy and objective sensitivity to food allergens.

Adult self-reported food allergy is also associated with higher household education level. However, food sensitivities are more common in individuals living in poverty and less common in high-income households.

As a result;

  • The frequency of food allergy and food sensitivity are different.
  • The frequency of food allergy in adults is 6.6% to 10%. It is as low as 1.3% above the age of 60
  • Food allergy sensitivity in adults is 14.9% in the United States and is quite high. These sensitization rates have been reported as 11% to 24% among Europeans.
  • It has been reported that while the frequency of food allergy is higher in those with higher education levels, food sensitivity is higher in the poor.