The World's Healthiest Foods

Can you tell me more about food and allergies to mold

Q. Mold allergy: Thanks for your amazingly informative newsletters. I have a few questions about allergies: If skin prick tests are positive for some pollen and mold allergies, but not for food allergies, which dietary precautions are necessary? Does cooking destroy mold in food? If so, how much cooking is required? (Would mushrooms, dried fruits, nuts, etc. be more acceptable cooked?) Also, is there any credibility to a "seasonal diet" that recommends avoiding certain fruits and vegetables at certain times of the year because they cross-pollinate with the trees/weeds that one might be allergic to? (And do you know specifically what that diet is?)

A. We'll try and respond to your questions one at a time. First, with respect to skin prick tests, most healthcare practitioners we've talked to do not find these tests helpful for determination of food allergy. According to these practitioners, the source of exposure in this case (a skin prick) is just too unlike the source of exposure (eating) that is involved with food. There are some blood tests for food allergy called ELISA tests, and sometimes these tests can be helpful. However, we believe that a good first step in determining food allergy is an elimination-challenge diet. We describe the principles of this approach on our website, and you can find that description in our "5 Health Promoting Diets" section under the "Allergy Avoidance Diet" heading. We would not recommend any automatic dietary precautions with the World's Healthiest Foods in response to a skin prick test involving environmental pollens and molds. However, there are definitely possible connections between pollen allergy and food, and we would like to tell you about a few of these. In the research literature, there is a syndrome called "pollen food allergy syndrome." This syndrome refers to the fact that allergy-triggering factors in certain non-food plants can be almost identical to allergy-triggering factors in food plants. The best studied plants and foods in this area are birch trees and Rosaceae family fruits. If a person reacts to birch pollen, he or she is also likely to react to fruits falling into the Rosaceae family. These fruits include apples, strawberries, cherries, plums, pears, blackberries, quinces, loquats, and currants. If birch was one of the pollens triggering an immune system response, you would want to consult with a healthcare practitioner to discuss what steps, if any, you would want to take with this Rosaceae family of foods. Kiwi is one other fruit (not a member of the Rosaceae family) that can trigger an immune response in individuals with birch pollen allergy. Mugwort pollen is another pollen that has been studied for food cross-reactivity, and in this case, mustard seeds and mustard greens are the foods that seem problematic.

Regardless of the environmental allergy that is triggering your immune system, however, when your immune reacts to environmental allergens, this added load might indeed require extra immune system support from your meal plan. In this case, you might want to focus on foods that are especially helpful in supporting your immune system. In our FAQ section, you'll find a question entitled, "What Foods Are Good For My Immune System?" and you might want to read over the information we provide in this section. Cooking does not automatically destroy mold in or on food. That's because some molds form spores and those mold spores are heat-resistant. For this reason, we would recommend avoiding molded foods.

You asked about cooking dried mushrooms and dried foods to minimize the chance of reactivity. We doubt such a step would be helpful from an immune system standpoint, since immune responses typically involve very small sections of proteins that would cooking would be unlikely to significantly alter. In addition, there would be increased loss of nutrients from these foods. We would also like to add that whenever possible, we recommend incorporating fresh foods rather than dried foods into your meal plan, especially fruits. The closer a food is to its whole, natural form, the more you can usually count on it to provide you with optimal nourishment.

We generally support the idea of a seasonal diet. Whole, natural foods vary from season to season, and while there is no high-quality research to support seasonal versus non-seasonal eating, the principles of seasonal eating make good sense to us. With respect to pollen and food allergy, yes, it would make sense to us for a person with a paricular environmental allergy like birch pollen allergy to avoid cross-reactive foods (like the Rosaceae fruits listed earlier) during those weeks when birch pollen counts were highest. We have not found a website that seems to cover these issues in a comprehensive and science-based way. However, you might want to visit the American Academy of Environmental Medicine at:, and click on the header entitled, "Find an Environmental Physician." On the next scree, just pick your state, and find a physician who is practicing in your area. AAEM physicians are often knowledgeable in the overlap between environmental and food allergies.