As if the burdens of age are not tiresome enough, the idea that we ‘grow out’ of allergies appears to be proving to be a reversible event.
Age-related immunoglobulin (Ig)E levels have risen significantly in both males and females in the United States since the 1970s, researchers announced at the American College of Allergy, Asthma & Immunology (ACAAI) 2010 Annual Scientific Meeting.
To gauge the temporal trend of age-related total IgE, the researchers analysed data from the National Health and Nutrition Survey (NHANES), a large cross-sectional database of the American population in 2005 and 2006. They then compared the results by age group with those of the earlier study known as the Tucson Epidemiological Study.
They found that subjects in the NHANES group had higher levels of IgE than those in the Tucson study, and that the IgE levels did not fall as much in the NHANES study with increasing age as they did in the Tucson study.
In the early years, in the 6 to 14 and 15 to 24 year age categories, the IgE levels were very similar in both the NHANES and the Tucson groups. But as the subjects got older, from the age of 25 on, IgE levels in NHANES subjects were significantly higher.
| Age group (years)* | NHANES, total IgE (kU/L) | Tucson, total IgE (kU/L) |
| 6–14 | 63.1 | 79.5 |
| 15–24 | 66.1 | 53.1 |
| 25–34 | 47.9 | 36.4 |
| 35–44 | 51.3 | 34.1 |
| 45–54 | 46.8 | 28.2 |
| 55–64 | 53.7 | 21.6 |
| 65–74 | 47.9 | 20.8 |
| 75+ | 39.9 | 17.1 |
This could be a true reflection of increasing allergy appearance or an indication of differing methods of data collection but many in clinical practice have noticed an increase in IgE allergies as well as a significant change in people overall immune tolerance.
As we age our immune system takes on a more inflammatory phenotype,[1] together with alterations in the microbial and nematode distribution throughout the western worlds gastrointestinal tracts there are a number of explanations for this trend.[2]
American College of Allergy, Asthma & Immunology (ACAAI) 2010 Annual Scientific Meeting: Abstract 51. Presented November 15, 2010.
[1] Goto M. Inflammaging (inflammation + aging): A driving force for human aging based on an evolutionarily antagonistic pleiotropy theory? Biosci Trends. 2008 Dec;2(6):218-30. Review. View Abstract
[2] Rook GA. Review series on helminths, immune modulation and the hygiene hypothesis: the broader implications of the hygiene hypothesis. Immunology. 2009 Jan;126(1):3-11. Review. View Abstract
