The Modern Epidemic: Food Allergies
We’re becoming more allergic to food.
Food allergies are getting more and more common in the modern world. With more than 10% prevalence in some countries, excess reactions to certain foods are a growing health problem. In the US, the number of people with food allergies is 32 million, of which 5.6 million are children. 40% of the children have allergies to more than one food.
Allergies occur when our immune system shows an exaggerated response to a substance, which is supposed to be harmless. Symptoms have an enormous range from red skin to vomiting to difficulty in breathing to anaphylactic shock. Allergies are most likely to occur in childhood, and some types such as milk, egg, and soy allergies often resolve. Unfortunately, allergies to nuts and fish seem to be lifelong.
The frequency of food allergies strikingly increased in the last 30 years, particularly in industrialized countries. Not surprisingly, lifestyle plays a significant role in this. Allergies are on the way to become the new epidemic of the modern era, without us realizing it. Why do more people develop allergies in the last few years? What can we do to avoid food allergies?
Too much hygiene brings allergies
One of the things industrialization and city life bring to society is more sterile and hygienic conditions. It might feel like the more sterile the environment is, the healthier you get, but the hygiene hypothesis rejects it. This hypothesis suggests that early encounter with microorganisms supports the immune system’s healthy development, decreasing the risk of infections and allergies. In other words, if you expose yourself to microbes early in life, your immune system recognizes them as nonharmful and wouldn’t overreact later.
However, It doesn’t mean that we shouldn’t wash our hands after a long time spent at work. It means that we, especially kids, should spend more time in nature, exposing to microbes. Indeed, living in a rural area and being more in nature decrease the susceptibility to food allergies.
As the early encounter of microorganisms does, the early introduction of certain foods in babies’ diets also strengthens the immune system, reducing the risk of developing food allergies. Food allergies are more common in babies who eat peanuts, milk, and egg for the first time after 1-year-old. In the case of peanut allergy, this risk is 10-fold higher than the babies eating peanuts within the first year of their life, as another study shows. Moreover, a lower incidence of egg allergies is reported in babies who eat eggs within 4–6 months of life.
Living in sterile urban bubbles and not tasting various foods during infancy make us sicker and more allergic. Unfortunately, the new hygiene habits due to the coronavirus pandemic might even increase the number of people with allergies.
Remember to take vitamin D
Vitamin D is unique, as being both a vitamin and a hormone, contributing to a healthy bone structure and immune system. A large study with more than 18,000 participants finds a higher risk of food-related severe allergic reactions in children with low vitamin D. Moreover, peanut or/and egg allergy is associated with insufficient vitamin D. Another study shows that vitamin D supplements improve allergic rhinitis symptoms.
At this point, you might be wondering whether vitamin D supplementation during pregnancy could lower the risk of allergies in the baby. A small number of studies find no relationship between vitamin D during pregnancy with a lower risk of allergy in children. Conversely, most studies indicate that the risk of developing allergies reduces in children whose mothers take vitamin D supplements in pregnancy.
Let’s suppose your mother during pregnancy or you as a baby couldn’t get enough vitamin D and developed reactions to a particular food. Could vitamin D supplementation reverse food allergies? There is not enough data to say so. Yet, clinical trials are essential to observe if vitamin D in adulthood can improve the existing allergies.
Despite all the evidence indicating its crucial role in food allergies, vitamin D may be the hardest vitamin to get enough. Our diet mostly lacks food containing vitamin D, and not everyone is living in a sunny area. In this case, supplements could help to meet the deficit. However, it is essential to remember that irresponsible vitamin D use might lead to toxicity, affecting the whole body, including bones and kidneys. Therefore, it’s best to keep track of vitamin D in the blood and take supplements accordingly.
Don’t forget the tiny friends in our gut
There is almost nothing that the little bugs in our intestines don’t influence in our bodies. We shape our microbiota with our lifestyle, environment, antibiotics use, and eating habits. In turn, our microbiota determines how strong our immune system will be. When those microbes become sad, that could make us pretty sad and even sick. Having a food allergy might be a cue indicating a disrupted microbiota.
Studies show that people with food allergies have a distinct bacteria profile in their guts. An imbalance of bacterial populations, termed dysbiosis, might lead to the overgrowth of harmful bacteria. This distinctive profile seen in allergic people might be even originating from the mode of delivery. Babies born via C-section develop a different microbiome than babies born via normal delivery do. Furthermore, C-section-babies’ microbiota is associated with a higher risk of developing inflammatory diseases and allergies later in life.
What is the way to have a happy, healthy microbiota? The most effective thing would be to consistently eat healthily. It’s essential to eat foods containing probiotics, which are beneficial microorganisms, and prebiotics, which are the food to nourish the beneficial microorganisms.
What about probiotics capsules? Using these could be dangerous without knowing which type of bacteria is missing or overgrown in the guts. Microorganisms in our guts should be in balance. If one or more grow excessively, it disrupts the whole balance and might lead to diseases. Discussing with a physician and taking a stool test to check the abundance of bacteria would be the best approach before using probiotics.
In some instances, even using probiotics can fail to restore the healthy gut microbe composition in the intestines. Although it sounds nasty, stool transfer is an effective way to support a happy microbiota. An ongoing phase I trial investigates whether fecal microbiota transfer is safe and effective in adults with peanut allergies. The results have yet to be known, but it will lead to more research on fecal transfer in food allergies.
Any other treatments for food allergies?
Some clinicians are trying to treat food allergies by giving increasing doses of the allergens to the patients, termed as oral immunotherapy. In January 2020, the FDA approved a capsule containing peanut powder to be used as a therapy for allergic patients. According to the research, 67% of the patients become tolerogenic to peanuts, meaning that they don’t react up to a specific dose, compared to 4% in the placebo group. Nevertheless, they are still allergic; they only become tolerated.
Our body produces IgE type of antibodies against foods, causing the allergy as a defense mechanism. Aiming to reduce the IgE antibodies in the blood, anti-IgE therapy is another treatment for improving food allergy symptoms. A clinical trial shows that combining anti-IgE therapy with oral immunotherapy improves people’s health with multiple food allergies. Once more, the participants of the study stayed allergic.
With a rising rate in the last years, food allergy is a candidate for becoming the modern epidemic. The most apparent reasons are urbanization and changes in lifestyle, environment, and eating habits that city life brings. However, it might be possible to decrease the incidence of food allergies by getting an adequate amount of vitamin D, eating to make the gut microbes happy, and being outdoors.
