Q. What are "tree nuts", and how do they differ from peanuts? Do I need to avoid both?
Tree nuts are a type of fruit from a tree. They consist of an oily seed encapsulated in a hard shell. They are not to be confused with peanuts, which are actually a legume (the same family as beans, lentils and peas) and are grown under ground. Botannically, these are two very different families, and they are not "cross-reactive." However, treenuts and peanuts are commonly processed in shared facilities, often on shared equipment even. Thus, there is a high risk that products containing peanuts may be contaminated with treenut proteins as well. Speak with a board-certified allergist about your level of treenut sensitivity, and whether you should avoid products with peanuts in them as well.
Q. Why might I need to avoid nuts?
Unfortunately, there are lots of reasons why you might need to avoid nuts. First and foremost, nuts are one of the eight most common food allergies, especially among children. Moreover, tree nut allergic reactions can be among the most severe. Tragically, some people have had fatal anaphylactic reactions to mere trace particles of nuts introduced into their system through cross-contact, or through non-food means. For this reason, if you think that you may have any reactions to nuts that you consult your doctor right away to conduct diagnostic tests to find out whether you have an allergy to nuts or may instead have a nut intolerance.
Even if your doctor determines that you do not have a nut allergy, which is a very specific immunological response, you may still have other adverse reactions to nuts. For example, both tree nuts and peanuts are among many foods that are high in histamine and may therefore cause a range of symptoms in people with histamine intolerance. Typically, food intolerance reactions are more delayed, are digestive in nature and are not life-threatening. In addition, unlike nut allergies, many people with nut intolerance may discover that their reactions are not "cross-contact sensitive" - meaning that they can tolerate trace amounts of nuts such as are introduced through cross-contact. However, every person (and in the case of nut allergies, every reaction) can be different - so it's critical to consult with a physician experienced in food allergies and intolerances to find out more about what is safe for you.
Q. But I thought nuts were good for you!That depends! Nuts are actually a perfect example of the driving idea behind freedible: that food is not one-size-fits-all! Obviously, if you have an intolerance or an allergy to nuts, they aren't healthy for you. However, for those who don't have adverse reactions to nuts, they can offer a wide range of health benefits. For starters, they are high in protein and according to the Mayo Clinic, most nuts have at least some substances (such as unsaturated fats, omega-3 fatty acids, fiber, vitamin E, plant sterols and L-arginine) that contribute to a healthy heart. Particular nuts may offer other health benefits as well, ranging from skin health to reducing memory loss. But obviously, none of these benefits outweigh the risks for people with a nut allergy or intolerance. Thus, if you think you might be having any kind of reactions to nuts, it's critical to consult with your doctor about whether nuts are an appropriate part of a healthy diet for you.
Q. What are the symptoms of a tree nut allergy? How is it diagnosed - and how is it treated?As in all allergic reactions, the symptoms of a nut allergy can range from mild (sneezing, itching, localized swelling) to severe (anaphylaxis, a reaction that can affect the body as a whole, including one or more of the following: a drop in blood pressure, fainting or dizziness, a swelling of the airway, shortness of breath, difficulty swallowing, chest pain, nausea, stomach pain, vomiting, diarrhea, a skin rash, itchy skin and/or hives over the entire body). No two individuals' reactions are alike - and even for one person each reaction can be vastly different from the next. You could have no noticeable reaction most of the time that you eat nuts, but then one day go into anaphylaxis without warning from just a trace exposure!
For this reason, if you or your doctor believes there is any indication that you may be having an adverse reaction to nuts, it is important that you work with a board-certified allergist to be tested for a possible nut allergy. To do so, your doctor will likely administer a skin-prick test (in which your skin is pricked with a small amount of a serum derived from the particular nuts for which you are being tested) and also a blood test to determine whether your body is producing antibodies to one or more nuts. It is possible that you may react to nuts in a skin-prick test for a variety of reasons that are scientifically distinct from (IgE-mediated) nut allergies; thus the blood test is considered the "gold standard" for determining whether you have the specific immunological response known as an "allergy".
If you do have a nut allergy, strict avoidance of tree nuts or items that could potentially contain tree nuts is the best treatment. If your body does have an anaphylactic reaction (whether caused by nuts, another allergen or conditions such as idiopathic anaphylaxis as can occur with, for example, some mast cell disorders), epinephrine, a life-saving medication, must be injected as quickly as possible. Moreover, anaphylactic reactions can be "bi-phasic", meaning that a second anaphylactic reaction can develop even after the first one passes. For this reason, if you are diagnosed with a nut allergy it is very important to create an anaphylaxis action plan with your doctor, even if you have not yet had a severe reaction yourself, and to always carry two epinephrine auto-injectors (EpiPen, Auvi-Q). If you suspect that you or someone you know is having an anaphylactic reaction, call 911 immediately.
Q. What about nut intolerances - what are the symptoms and how is that diagnosed?Nut intolerances, like all food intolerances, can be tricky to diagnose. To date, there is no reliable blood test for food intolerances - rather, patients are still forced to rely on elimination diets and careful food journaling. Further complicating things, food intolerances can cause such a wide range of seemingly-unrelated symptoms. These may include gas, cramps, bloating, heartburn, headaches (including, for some people, migraine headaches), irritability and nervousness. Moreover, food intolerance reactions typically set in more gradually, as your body works to digest the offending food, which can make it difficult to narrow down which particular food is causing your reactions.
However, like all foods (even non-GMO, organically-grown ones!), nuts are a combination of multiple chemical substances. How your body breaks down, processes and absorbs these compounds is similarly complicated - and how well your particular body is able to digest a given food depends on a number of factors, including your genetics, how much you create of a particular enzyme, etc. Thus, depending on how that particular chemical affects the body, you may have symptoms affecting your digestive tract but also other parts of your body that are seemingly unrelated to food.
To give an example, many nuts are naturally high in histamine, a chemical naturally occurring in many foods that is also produced by your body if you have an allergic reaction - whether to a food, tree pollen or the family cat. If your body does not produce enough of the "DAO" enzyme you need to break down the amount of histamine present in your body at a given time, it will build up as a toxin in any cell or tissue that has a histamine receptor, including your gut, your heart, your lungs and your brain. This condition is known as "histamine intolerance." If your particular body's reaction to nuts happens to be driven by a histamine intolerance, your symptoms may include such unlikely things as "brain fog", asthma attacks, tachychardia (a sudden racing of the heart) and more. This all just underscores how important it is to work with your physician and conduct the necessary medical tests to ascertain not just what you are reacting to but why.
In general, to diagnose a food intolerance, your doctor may ask you to go on an "elimination diet" in which you avoid any foods that you or your doctor believes may be triggering your symptoms for several weeks, while maintaining a detailed food journal to track your general health and any symptoms you experience during the time of the trial. The suspected foods are then reintroduced into your diet one at a time, while still keeping track of all the foods you eat and any symptoms or reactions you have. By examining your food journal, your doctor will then be able to make recommendations about what foods may be problematic for you.
Depending on what element in nuts your body is "intolerant" to, you may find that you are able to tolerate some nuts better than others. Working with a physician or dietitian who is well-versed in the differences between the various types of nuts, you may be able to better predict which nuts will work for you, if any. However, because nut allergy reactions can be so severe, it is important that even people who believe their reactions are caused by a nut intolerance get properly tested by a trained allergist or immunologist to rule out the possibility that you may instead have a nut allergy before conducting any experiments to see if you react to all nuts or only some of them.
Q. Can I react to one type of nut but not to another?
Within the class of "tree nuts," there are several different sub-classes, which are in many respects botanically unrelated to one another. Thus, whether your reactions are driven by the specific immunological reaction known as an allergy or are instead driven by a nut intolerance, it is possible that you may need to avoid all types or sub-classes of nuts, or just one. For instance, someone may have adverse reactions (including both allergies and intolerance) to walnuts but not to almonds, because they are in different sub-classes.
The only way to find out whether you are reacting to all nuts or just to some is by working with your doctor to test each individual nut. Furthermore, since most nuts are processed in the same facility or even on the same equipment and thus may come in contact with one another, the risk of having a reaction because of cross-contamination is very high. Thus, most allergists recommend that anyone with a nut allergy avoid all tree nuts. For the same reason, they may also recommend that you avoid all peanuts as well.
Because nut allergy reactions can be so severe and there is so much overlap in the symptoms of the two, it is important that even people who believe their reactions are caused by a nut intolerance get properly tested by a trained allergist or immunologist to rule out the possibility that you may instead have a nut allergy before conducting any experiments to see if you react to all nuts or only to some of them.
Q. My child reacts to nut - will he or she outgrow this?
That depends. For starters, whether your child is likely to outgrow their reactions depends on whether they are caused by an allergy or by some other type of sensitivity. Of all of the "top 8 allergens" (that is, the 8 most common allergies, which are responsible for 90% of all food allergy reactions), tree nut allergy is the least likely to be outgrown. According to FARE, only approximately 9 percent of children will have outgrow their nut-allergy by adulthood.
With respect to nut intolerances, this will depend on the cause of the intolerance. Only time, and consulting with your doctor, will tell.
Q. What are some hidden nut sources?
Alas, there are many, and because nut allergy reactions to even trace amounts can be so severe, it is important to familiarize yourself with them. For your convenience, we have provided a Nut-free Cheat Sheet that you can print and take with you or give to relatives and caretakers with many of the hidden sources of exposure to nuts. However, it is critical that you read the labels on any food or other product through which you may be exposed to nuts, and contact the manufacturer directly to confirm that it is safe for you to use or injest a particular product.
Q. Do I need to avoid peanuts?
Tree nuts and peanuts are from entirely different botanical families. Peanuts are not a true nut, but rather a legume and as such are closely related to beans, lentils, and peas. Thus, some people with tree-nut allergies or intolerances can safely eat peanuts. However, many people, including in particular many tree nut-allergic children, react to both peanuts and tree nuts. The only way to know for sure is to work with your doctor. Additionally, as noted above, tree nuts and peanuts are often processed together in the same facility or even on the same equipment, thus creating a high risk for a cross-contact reaction between the two. For this reason, many health care professionals recommend that their nut-allergic and nut-intolerant patients avoid both. Speak to your doctor about your personal food restrictions and what precautions you should take.
Q. Do I need to avoid coconut?
According to The American College of Allergy, Asthma and Immunology (ACAAI), “Coconut is not a botanical nut; it is classified as a fruit, even though the Food and Drug Administration recognizes coconut as a tree nut. While allergic reactions to coconut have been documented, most people who are allergic to tree nuts can safely eat coconut. If you are allergic to tree nuts, talk to your allergist before adding coconut to your diet." The same can be said for people with nut intolerances: talk to your doctors about whether they believe you should avoid coconuts as well.
Q. What about nutmeg (or mace), water chestnuts, or butternut squash?According to FAAN, "Nutmeg is obtained from the seeds of the tropical tree species Myristica fragrans. It is generally safe for an individual with a tree nut allergy." (Here's an informative article about the difference between tree nuts and seeds by Onespot Allergy.)
The water chestnut is a grass-like plant with an edible corm (an underground stem that resembles a bulb). Butternut Squash is a type of winter squash know for its mild, sweet orange flesh. Neither of these is related to tree nuts and therefore people with tree nut reactions can generally eat these foods without incident (that is, assuming you don't have an unrelated allergy or intolerance to them!)
Q. What cuisines or types of restaurants should I avoid if I need to avoid nuts?Many cuisines rely heavily on nuts, nut pastes or powders and other nut derivatives, including Thai, African, Mexican, Vietnamese, and Middle Eastern food. Of course, it is possible to enjoy these cuisines without using nut products but eating in restaurants that serve these foods presents a high risk of being exposed to nuts through cross-contact during the food's preparation. Thus anyone whose nut reactions (whether caused by an allergy or an intolerance) is cross-contact sensitive would be well-advised to avoid eating in restaurants that serve these cuisines, and to exercise caution when purchasing ingredients typically sold for these types of cooking.
Ice cream parlors, salad bars and bakeries similarly present a high-risk of cross-contact to nuts. Anyone with severe food reactions, to any ingredients, are also well-advised to avoid buffets and similar settings that are highly prone to cross-contact.
Q. Where can I learn more?Check out these sites to learn more:
FARE - Nut Allergies
No Nuts Moms Group - Foods to Avoid
Avoiding Milk Protein - Alcohols Containing Nuts
Avoiding Milk Protein - Prescriptions and OTC Medications Containing Nuts
Kids With Food Allergies - Tree Nuts