While you may not associate food with lung health, certain foods can have a negative effect on your breathing. To help improve lung health, avoid processed foods and eat more fresh fruits, vegetables, roots, and nuts.

If you find yourself short of breath after eating, try pursed lip breathing to clear mucus from the lungs.

1. Sulfites

Sulfites are sulfur-containing chemicals used as food preservatives to prevent bacterial overgrowth, browning and spoilage. They're also used in some medicines and cosmetics.

When sulfites are digested, they create sulfur dioxide, which can irritate the airways and cause difficulty breathing. Sulfur dioxide can also trigger asthma and other allergies.

In people who are sensitive to sulfites, the reaction can be severe and even life-threatening. Common symptoms include flushing, rapid heartbeat, wheezing, hives and dizziness. In very rare cases, sulfite sensitivity can lead to anaphylactic shock.

There's no reliable blood or skin allergy test for sulfite sensitivity, so your doctor may need to run a controlled sulfite challenge under supervision to determine if you are sulfite-sensitive. He or she may recommend an elimination diet followed by gradual reintroduction of foods to see if your symptoms improve.

2. Salicylates

Salicylates are naturally occurring compounds produced by plants to ward off opportunistic insects and protect the plant from disease. The same chemicals are found in over-the-counter pain relievers like aspirin and serve as preservatives in many foods including dried fruits, tomatoes, vinegar, jellies and jams. For a select few people, ingesting salicylates triggers gastrointestinal symptoms and asthma flare-ups.

A dietary elimination and challenge process under the guidance of a functional medicine practitioner can help determine if you are sensitive to salicylates. If you are, avoiding foods high in these chemicals can greatly reduce symptoms and improve overall health. When salicylate sensitivity is present, my clients often find that consuming more protein and omega-3 fatty acids improves their symptoms. In addition, they can take a low salicylate diet to help decrease chronic inflammation that can exacerbate the symptoms of eosinophilic rhinosinusitis and nasal polyps.

3. Excess Sodium

Sodium (salt) is an essential nutrient needed in small amounts to maintain body fluid balance, keep muscles and nerves working properly and make blood pressure normal. However, too much sodium causes the body to retain water and lead to high blood pressure – one of the leading risk factors for heart disease.

It is hard to know how much salt you are eating because taste can be deceiving. Many processed foods - even those that don’t taste salty – are high in sodium. In fact, it is common for people to get over a day’s worth of sodium from packaged foods without ever picking up a salt shaker.

To cut back on sodium, read the Nutrition Facts label and choose lower-sodium foods. Eat fresh fruits and vegetables, avoid canned foods with added salt and rinse and drain canned beans and tuna before using.

4. Dairy Products

Dairy foods, like low-fat or fat-free milk, yogurt and cheese provide a rich source of protein and calcium. They can also be a great way to add flavour and variety to a meal.

However, there are some people who have a food allergy to dairy and it can lead to an inflamed and thickened esophagus, causing difficulty swallowing. They may also suffer from a chronic inflammatory condition called eosinophilic esophagitis (EoE), which triggers a flare of asthma symptoms.

Milk isn’t harmful for people with asthma who don’t have a dairy allergy or milk intolerance, but it shouldn’t be consumed melted on fast-food burgers and pasta, which are high in saturated fat and sodium. Eating too much dairy can lead to overweight and obesity, which can further trigger asthma symptoms.

5. Carbonated Drinks

According to the American Lung Association, soda can be detrimental to lung health. The bubbly beverage can cause gas and bloating, as well as trigger asthma. The Cleveland Clinic recommends avoiding carbonated drinks and drinking six to eight glasses of water daily instead. In addition, soda can reduce your nutrient intake, including protein, starch, dietary fiber and vitamin B-2, known as riboflavin.

Fatty foods like fried chicken, fries and other greasy fried snacks can increase mucus production and make breathing more difficult. They can also lead to weight gain, which puts a strain on your heart and lungs. Keep a food diary to see how certain foods affect your breathing. Then, make healthy choices to improve your overall pulmonary health.