What causes food allergies?

The number of people with potentially deadly food allergies in the U.S. has risen steadily in recent years, and according to Food Allergy Research & Education, as many as 15 million people now have such allergies. But one thing remains unclear: why?
There are several theories on why the number of food allergy cases is rising, but no clear-cut explanation. FARE CEO John Lehr said that despite ongoing research, "...we don't actually know why there's an increase."
Dr. Lisa Roth, an allergist based in Lynbrook, said that over the last five to seven years, she has seen a significant increase in food allergy patients.
According to a Centers for Disease Control and Prevention study released this year, the number of food allergies increased approximately 50 percent between 1997 and 2011. One in every 13 children under 18 now has a potentially deadly allergy.
Lehr and Roth support a theory, known as the hygiene hypothesis, that people's immune systems are being negatively impacted by excessive cleanliness. "In the developed world, we're almost too clean," Lehr said. "Our immune systems are maybe being downgraded, and that makes [them] more vulnerable to things like food, which should be harmless but are now viewed as a potential threat."
Roth said that while hygiene is important in preventing other diseases, our bodies need a certain level of microbes and bacteria in order for our immune systems to develop normally. "We need balance," she said. "If something isn't quite right, there becomes an imbalance."

A reaction can come at any time

A food-allergic body, Roth explained, misreads a food, normally a nourishing source of energy, as something harmful and reacts negatively. In the U.S., a reaction to a food allergy sends someone to an emergency room every three minutes, according to FARE, and every six minutes that reaction is anaphylaxis — a severe, potentially fatal condition.
When a person with a food allergy tastes, touches or even smells the wrong food, the respiratory system, the skin, the gastrointestinal tract and the cardiovascular system can be affected, Roth said. The most common way a reaction is triggered is by taste, and when it occurs, it is important to administer epinephrine quickly. Roth called epinephrine the "gold standard" for stopping the progression of anaphylaxis brought on by food allergies.
"There is nothing more important to anyone with a food allergy," Lehr said, "or even an environmental allergy, than making sure you're carrying epinephrine ... at all times, because an accidental exposure to a food allergen can happen anywhere, any time."

A cure on the way?

Food Allergy Research & Education, a nonprofit that was formed in 2012 after the merger between Food Allergy & Anaphylaxis Network and the Food Allergy Initiative, raises millions of dollars each year to fund research into possible cures, spread awareness, encourage government advocacy and educate people about food allergies. FARE is the largest private funder of food allergy research in the world.
The most promising treatment for food allergies, which is still in clinical trials, is oral immunotherapy, or OIT. During OIT, the food allergen — in powder form, mixed with a harmless food — is administered gradually, in small but steadily increasing doses, until the patient is desensitized to it.
Studies show, Lehr said, that between 70 and 80 percent of people with food allergies can be desensitized, which is why OIT is so promising — although it is FARE's goal to desensitize 100 percent of food allergy sufferers.
Roth said she hopes to one day treat patients with OIT, but she added that the treatment is a long way away from being approved by the Food and Drug Administration.

Go to and search "food allergies" for the first and second installments of this series.


Lisa Roth, MD
10 Union Ave. Suite 11A&B
Lynbrook, NY 11563
Office: 516-599-6910
Fax: 516-612-3402

Pollen Forecast


  • When a local ENT first referred me to Dr. Roth several years ago, I was dependent upon Allegra pills and Nasacort nasal spray to function throughout the day -- and not comfortably. Now, with monthly visits to Dr. Roth for allergy shots, I no longer... View More..
    Adam from Long Beach, NY

  • My winter allergies had gotten so bad that I had to leave in the middle of a business meeting. I was at my wit’s end and finally called Dr. Roth. Since receiving Dr. Roth’s personalized treatment, I am free from suffering – not only do I no... View More..
    Joy from Oceanside, NY

  • I have been under the care of Dr. Lisa Roth for many years. Sadly, I have severe allergies to almost everything that a person breathes in. Luckily, because of Dr. Roth, I am able to enjoy a normal life including taking long walks outdoors – even... View More..
    Laurie from Lynbrook, NY

  • Several years ago, at the age of sixty, I was diagnosed with allergy induced asthma. At times, I would struggle for breath and experience intense wheezing in my chest. I then found Dr. Lisa Roth and after a thorough diagnosis, began receiving... View More..
    John from Long Beach, NY

  • Due to Dr. Roth’s professional care, it took only a few visits before I noticed a dramatic improvement in my allergy symptoms. Dr. Roth was very informative concerning my allergies and the progress made throughout my visits. As a professional, I... View More..
    Alan from Valley Stream, NY

  • The level of care offered by Dr. Roth is exceptional. Her concern and expertise is evident the moment you meet her. The migraine headaches I used to suffer during the spring pollen season are now just a memory. Dr. Roth’s office hours allow even... View More..
    Tom from Lynbrook, NY

  • When I came back from a trip abroad in 2011, my allergies became unbearable. I was constantly congested and coughing, my asthma would act up daily and I would get a sinus infection or a cold every month even though I was taking allergy medicine... View More..
    Kathryn from Lynbrook, NY