Study gives light at the end of the peanut allergy tunnel
Source of Article: http://www.foodnavigator.com/Science-Nutrition/Study-gives-light-at-the-end-of-the-peanut-allergy-tunnel
By Stephen Daniells,
exposure to peanut may put an end to peanut allergy, if results of a small
study from Cambridge
are followed by similar positive results.
Scientists from Addenbrooke’s Hospital in Cambridge exposed four
peanut-allergic children to gradually increasing quantities of peanut
protein, and found that all the children can now tolerate about 800 mg grams
of protein, which is the equivalent to five peanuts, per day.
Dr Andy Clark and his
co-workers report their results of their study in the journal Allergy.
Although the study is
small, the implications could essentially be huge. Peanut allergies are
rising in humans, with an estimated 2.5 million people in Europe and the US now
vulnerable to the food allergy.
There is no current
cure for food allergy and vigilance by an allergic individual is the only way
to prevent a reaction but a peanut allergy
can be so severe that only very tiny amounts can be enough to trigger a
recommendations in many countries, such as the UK
and the US,
for would-be mothers are to avoid peanuts during pregnancy, breastfeeding,
With peanut allergy
potentially fatal for some people, food manufacturers are already bound by
certain regulations, depending on the country, to highlight possible allergens
in a food product, such as the EU’s Labelling
Four children give
Dr Clark and his
co-workers recruited the four children aged 12, 13, 9, and 13, and
investigated if peanut oral immunotherapy (OIT) could induce clinical
tolerance to peanut protein.
An initial challenge
confirmed the presence of peanut allergy in the children, with one of them
experiencing anaphylaxis that required an injection of adrenaline. These
initial tests revealed dose thresholds ranging from five to 50 mg, which is
the equivalent to between 0.025 and 0.25 of a peanut.
The children then
began OIT as daily doses of peanut flour. The doses increased fortnightly
from 5 to 800 mg of protein. Six weeks later, the oral challenge was
repeated, and the new dose threshold values calculated. At the same time,
subjects continued daily treatment.
During the post
intervention challenges, the four children were found to tolerate at least 10
whole peanuts, or 2.4 grams of protein, said the researchers. This equated to
a dose threshold increase of 48-, 49-, 55- and 478-fold for the four
“Each subject is
currently tolerating approximately 800 mg protein (five peanuts) per day, and
can tolerate at least double that amount on oral challenge,” wrote Clark and his
“Tolerance may be lost
if subjects were to stop OIT at this stage, and it is likely that long-term
maintenance is required, as for other forms of immunotherapy.
“Follow-up studies are
therefore required to examine the duration and frequency of maintenance
therapy required to induce long-term tolerance,” they concluded.
Early exposure may be
A recent study
comparing incidence of peanut allergy in Jewish children in the UK and Israel
(where no recommendations for peanut avoidance exist) showed that children in
were 10 times more likely to suffer from peanut allergy than their Israeli
Findings in the Journal
of Allergy and Clinical Immunology showed that 69 per cent of Israeli
children were consuming peanut, while only ten per cent of the children in
were eating peanuts.
Published online ahead of print, doi:
"Successful oral tolerance induction in severe peanut allergy"
Authors: A. T. Clark, S. Islam, Y. King, J. Deighton,
K. Anagnostou, P. W. Ewan