This article, I think, will appear in the Annals of Allergy
Asthma and Immunology. The lead author
is S. Shalzad Mustafa at the University of Rochester School of Medicine and
Peanuts and tee nuts;
- Common and serious food allergens
- Frequently seen together in ‘mixed nuts’ which
by the way would more appropriately be labeled as mixed nuts and peanuts!
- Commonly tested together by allergists
- Appear together in the infamous food allergy
- Common cross contact or contamination concerns
- If allergic to tree nuts often told to avoid
This article contained many refreshing and challenging ideas.
Historically, those with peanut allergy were always told to stay away from tree
nuts. Was that good advice? What was it
based on- real biological cross-reactivity or industrial contamination? What is
the ‘real-life’ story here? Why avoid a food or class of foods that have a
health benefit if there is no real allergy? Remember that a sensitized person
has only a positive allergy test and an allergic person has that test positive
AND a symptoms/reactions with exposure.
This article pulled a few facts from the literature on tree
nut allergy those with peanut allergy.
- There is a high rate of sensitization to tree
nuts in the peanut-allergic population
- The rate of food challenge proven tree nut
allergy in the peanut-allergic group is 7%.
- Tree nut milk products provide a milk substitute
in the milk/soy allergic individual.
- Tree nut consumption decreases the risk of
cancer and cardiovascular disease.
- The more foods you are told to avoid, the more
miserable you are (Quality of Life).
- Tree nut free food shopping can be stressful
(back to Quality of Life issues).
- Almonds are the most common tree nut in the
- Brazil nuts were not included- not commonly
consumed – I always thought so. Great source of selenium, but not the tastiest
(I think this is a fact!)
Purpose of the paper-
a real-world cross-sectional analysis of tree nut sensitization in the
peanut-allergic population that includes; allergist’s recommendations, actual
consumption, and factors related to these behaviors. This is more of a descriptive
used an allergy practice in Rochester, New York. Individuals had to have had a
diagnosis of peanut allergy.
Results- 258 participants were in this report
- Egg was the most common other food allergy reported
- 33.3% had peanut and egg allergy.
- The most common presentation of the peanut
allergy was hives/swelling -43%
- Anaphylaxis was reported in 16.7%
- 88.8% had no unintentional exposure to peanut
within the past year. (We do a very good job with avoidance)
Tree Nut Observations- on those with peanut allergy
and tree nut sensitization
- 36.8% consumed all tree nut ad lib – No
- 24.4% consumed some, but not all tree nuts
- 38.8% (100) consumed no tree nuts. Within this
- 50% avoided due to perceived risk of
- 16% No Way
or no desire to eat any tree nuts
- 13% avoided due to age
- 12% avoided due to high risk of being allergic (skin/blood test)
- 7% avoided for the sake of a family member
- 2% avoided for ‘other’ reasons
- 50% avoided due to perceived risk of
- Tree nut sensitization rates were all about the same
- Almond - 45.3%
- Cashew – 54.3%
- Hazelnut – 50.8%
- Pecan – 43.4%
- Pistachio – 43%
- Walnut – 45.7%
- Allergist recommendations for consumption
- Almond – 73.3%
- Cashew – 51.6%
- Hazelnut – 65.9%
- Pecan – 69.8%
- Pistachio – 51.6%
- Walnut – 68.8%
- Rates of sensitization for the tree nuts ranged
43-54.3%. (2008 article 49-78% and 2019 article 38-50% rate of tree nut
- Highest blood tests were for cashew and
- Lowest blood tests were for almond and hazelnut.
Almond had the lowest rate of
sensitization and cashew had the highest rate.
- The TRUE rate of tree nut ALLERGY (having a
reaction) is lower than the previously reported level of 30% (2011 & 2013).
- High rates of almond and hazelnut sensitization
may be attributable to birch tree pollen cross-reactivity.
- Avoidance of all tree nuts was due to fear of
cross-contact with peanut.
- Willingness to consume foods with precautionary
labeling was the most important factor for tree nut consumption. When there is a peanut allergy and products
are eaten that say they may contain tree nut there was more willingness to
broaden the diet to include tree nuts.
- There should be a revision of the discussion of
tree nut avoidance in those with peanut allergy.
Individuals with peanut allergy are
frequently sensitized to tree nuts- they have positive allergy tests. With
exposure to foods with tree nut precautionary labels by a family, there is a
tendency to consume tree nuts. The data suggests the potential for safe
introduction of tree nuts in peanut-allergic patients and those who will do
this are those who consume foods with the tree nut precautionary label.
That last part is a bit confusing- my take
Peanut allergic patients will have positive
tests to tree nuts, but no story of reactivity, just a positive test. The
recommendations would be avoidance of peanut for sure, but if the patient
indulges in foods that have a precautionary label regarding - may contain tree
nuts and they have no problems, there is a tendency for progression and
consumption of some or all tree nuts over time- describing more of a behavior
or approach by the patient/family blended with support/advice from their
There clearly is a tendency to lump tree nuts in with
peanut. Food allergy testing leads to
many restrictions. The more you test, the greater the chance of having more
Note this is not applicable to TREE NUT ALLERGY. This applies
to those with PEANUT ALLERGY who had positive tests only to tree nuts.
This is a very interesting approach to tree nut
sensitization. There are a number of
issues to consider-
- Why test for tree nuts when peanut was the food
of concern? The literature reveals an expected high rate of positive tests and
a low rate of reactions.
- Why advocate full avoidance with sensitization?
Those who with tree nut sensitization who do not abide by precautionary
labeling and have exposure tend to evolve towards tree nut consumption. Perhaps the exposure with the ‘may contain’
labels when met with no reactivity strengthens the resolve towards full
- Patient/family behavior is a strong determinant.
Why do they avoid the tree nuts? Most are concerned with peanut cross-contact.