5 Foods That May Trigger Asthma Flares

Though rare, food allergies can trigger asthma, notes the Cleveland Clinic. And the calorie-free sweetener aspartame, commonly used in diet sodas, is one of many food additives suspected of causing allergic reactions, according to the Asthma and Allergy Foundation of America (AAFA).

“Food allergy symptoms can mirror — or even worsen — the symptoms of asthma and vice versa,” says Peg Strub, MD, an allergy specialist in the San Francisco area. It’s best for people with breathing difficulties to avoid chemicals like aspartame that might cause allergic reactions, she says.

Many processed foods contain preservatives and artificial colorings that may worsen lung inflammation.

“A lot of highly processed foods, such as fast foods, deep-fried foods, packaged foods, and frozen foods, seem to increase asthma symptoms,” McCormack says. She advises her asthma patients to limit these foods and instead focus on in-season whole fruits and vegetables.

Research suggests that following a traditional Western diet, which is high in fat and processed foods, is linked to higher risk of asthma than following a diet with less processed food, according to a study from 2014. And a study published in 2017 found that eating processed meat four or more times per week was associated with worsened asthma symptoms over a seven-year period.

Although the evidence for the effect of specific additives on asthma symptoms is limited, you may want to be wary of the following, according to the AAFA:

• Parabens Preservatives used in foods and medicines.
• Tartrazine A dye used in sugary drinks, ice cream, and hot dogs.
• Nitrates and Nitrites Preservatives used in processed meats such as hot dogs, bologna, and salami.

“As a general rule, if it came from a plant, eat it,” Dr. Gundersen says. “If it was made in a plant, don’t eat it.”

Desserts, red meat, and other fatty foods contribute to obesity, which can worsen inflammation and lung function and exacerbate your asthma symptoms, according to research from 2020. Maintaining a healthy weight is vital when you have a chronic health condition like asthma, McCormack says. If you’re overweight, your lungs have to work harder, she adds, which can aggravate asthma symptoms.

Not all fatty foods should be limited or avoided, however. McCormack emphasizes that some fats, such as those found in fish, avocados, olive oil, coconut oil, and nuts and seeds are healthy for people with asthma. Oily fish, like salmon, also contain omega-3 fatty acids, which can help people with asthma fight inflammation, according to a study from 2015. “Substituting fish for red meat whenever possible is always a good idea,” McCormack says.

Sulfites, commonly used as a preservative in wine and some beers, may worsen asthma for those with moderate to severe symptoms,Somewhere between 1 in 40 and 1 in 100 people with asthma have a sulfite sensitivity, per the Cleveland Clinic.

Additionally, sulfites can be found in dried fruit, shrimp, pickles, and condiments, according to the AAFA. Jennifer Musser, a registered dietitian in Denver who works with adults who have inflammation-related chronic conditions (including asthma), says it’s best to avoid them — or at least limit your intake — if you have chronic breathing problems. It’s also a good idea to speak with a doctor for insight on what to avoid and what to do if you have a reaction.

Finally, another food category you may have been told to avoid if you have asthma is dairy. It’s long been thought that dairy products like milk and ice cream worsen asthma symptoms because they increase the production of mucus in the lungs. Dr. Strub says there’s little scientific evidence to support that theory.

But dairy may be a trigger food for some, so it may be a food for you to monitor and discuss with your doctor. If dairy doesn't trigger asthma symptoms for you, moderate consumption can help you stick with a balanced, healthy diet, Strub says. Greek yogurt, for instance, is packed with probiotics and is a good source of protein.

Additional reporting by Moira Lawler.