Scientists have theories about the rise in food allergies related to our modern lifestyles, namely the five “D” hypotheses.
Thirty-three million Americans have food allergies, 1 in 10 adults and 1 in 13 children, and the numbers are rising globally. Food allergies in children have increased by 50% since the 1990s, with similar numbers recorded in Canada – 1 in 13 Canadians having at least one food allergy.
Also, once seen as primarily limited to childhood, allergies are now an adulthood disease, with more women than men experiencing food allergies. Studies suggest that a lack of gut microbiome and vitamin D may play a role in the onset of food allergies.
What is a food allergy?
When the body mistakenly perceives a harmless food protein like dairy as a potential threat, resembling a virus or bacterium, it promptly activates a defense mechanism to ward off the perceived invader. For example, in a person with a dairy allergy, the immune system sends off an army of antibodies called immunoglobulin E (or IgE for short), which involves releasing more inflammatory chemicals like histamine, leading to various symptoms. These symptoms can occur within minutes and range from mild reactions, like itching, hives, rashes, or gastrointestinal distress, to extremely severe reactions, such as anaphylaxis (a life-threatening condition).
What are the most common food allergens?
The nine major food allergens are milk, eggs, peanuts, tree nuts, sesame, fish, shellfish, soy, and wheat.
Food allergies vs. food intolerances?
Unlike food allergies, a food intolerance does not involve the immune system; instead, it’s an inability to digest certain foods (e.g., lactose or gluten) because of the lack of specific enzymes. Symptoms usually develop more slowly, within hours or days, and include gastrointestinal symptoms like bloating, gas, and diarrhea. If you wonder whether you have an allergy, intolerance, or another condition like celiac disease, it’s best to get a proper diagnosis from your doctor.
Why the rise in food allergies worldwide?
Food allergies seem to run in families to some extent; however, environmental factors like air pollution, tobacco smoke, or chemicals in our water and food may play a more significant part than our genetics. Scientists have theories about the rise in food allergies related to our modern lifestyles, namely the five “D” hypotheses.
1. Dirt hypothesis, or the reduced exposure to microbes during childhood (excessive cleanliness).
2. Dry skin and eczema that cause itchy and cracked skin, allowing allergens to enter the body. Infants with eczema are at a higher risk of developing food allergy.
3. Detergents in synthetic laundry or dish soaps that disrupt the skin barrier and cause dry, “leaky” skin.
4. Deficiency in vitamin D because of sedentary (indoor) lifestyles, affecting the development of a healthy immune system necessary for skin and gut health.
5. Decline in diet diversity and gut bacteria because of modern agriculture and the global food system.
Another significant factor is air pollution. Studies suggest that infants exposed to air pollution during their first year of life are more likely to develop allergies to food, mold, pets, or pests.
Can we prevent food allergies?
According to Dr. Kari Nadeau, an expert in allergy and immunology, we can all reduce our risk of getting a food allergy by addressing the five Ds and building a robust immune system.
A healthy gut microbiome. Follow a diet high in fiber and healthy fats (such as omega-3) and consider probiotics. Avoid processed, “allergenic” foods with added sugars, preservatives, emulsifiers, etc. Pregnant women and infants as early as
4–6 months should be exposed to a diversified diet and different proteins from foods (i.e., potential allergens) to train the immune system.
Healthy skin, vital in infants. Nourish the skin with natural lipids like ceramide instead of emollients like petroleum, Vaseline, and paraffin, which can increase bacterial growth and trigger inflammation. Use eco-friendly detergents.
Vitamin D. Low vitamin D levels are associated with eczema severity and intestinal inflammation; consider vitamin D supplements.
How are food allergies treated?
Strictly eliminate the foods you are allergic to and carefully read ingredient labels. When dining out, ask about food preparation methods and hidden allergens in processed foods.
Consider oral immunotherapy if you have severe allergies. The gradual exposure to increasing doses of an allergen over time, under strict medical supervision, may desensitize your immune system to it.
Have an emergency action plan if you have severe allergies. Always carry an epinephrine injector (known as an EpiPen®) – the only lifesaving tool to prevent death if properly used (learn how to use an EpiPen correctly).
Living with allergies can be challenging, but early detection and proper treatment can improve quality of life. Remember, keep your gut and skin microbiome healthy (get enough vitamin D) to build a strong immune foundation.
