Asthma sufferers have a harder time taking in normal amounts of air. Different parts of the lungs respond to different triggers, so sufferers must be extra vigilant about what they’re eating to avoid triggering a reaction. That means avoiding foods that can irritate the respiratory tract and cause inflammation. While many different things can trigger an asthma attack, the following foods are known to be the worst offenders:

1. Acidic foods and drinks
Acidic foods can affect the lungs in many negative ways. In some cases, they irritate the respiratory tract, making it more likely that an asthma attack will occur. In other cases, acidic foods can lead to inflammation of the airways that can trigger an asthma attack. Foods with a pH below 6 are known to trigger inflammation and can lead to a massive increase in mucus production. This is also why eating too much acidic food can cause indigestion or gas.

2. Cold cuts
Patients with asthma may be sensitive to the preservatives used in foods containing nitrates. Nitrates can lead to an asthma attack if they are consumed in high quantities. If you have asthma, it’s generally recommended that you avoid foods or drinks with nitrates. These include most types of hot dogs, sausages, and smoked meat. You should also avoid or moderate your intake of cured meats such as salami and hot dogs, which contain high levels of sodium nitrate for preservation purposes.

3. Carbonated beverages
Patients with asthma may also be sensitive to carbon dioxide, which is found in all carbonated beverages. Carbon dioxide (or C02) can cause an asthma attack if it builds up in the body. This can lead to shortness of breath and wheezing. Carbonated beverages, like soda, sparkling water, and seltzer contain high amounts of carbon dioxide, which can inflame the lungs and trigger an asthma attack.

4. Dairy products
Dairy products are often a problem for patients with asthma. These may include milk, cheese, and yogurt made from animal protein (e.g., cow). This is because they usually contain high levels of lactose, which can cause excess mucus and lead to an asthma attack. If you can’t completely avoid these products, try to eat them in moderation so as not to trigger an attack. You could also choose plant-based dairy options (e.g., almond, soy, or oat based milk products) or lactose-free milk products.

5. Salty foods
Salty foods like chips and crackers can trigger an asthma attack. Studies show that high levels of sodium chloride (salt) can cause the airways to swell and constrict, making breathing more difficult in already susceptible patients.

If you have asthma, it’s important to limit your intake of the above foods. Talk to your doctor about how diet may be worsening your asthma symptoms, and ask for recommendations on therapies, prescription medications, and aids—such as a quiet pure air filter for asthma—which can improve your breathing and quality of life.