If the eyes are a window to the soul, then the lungs are a door to the body—providing a gateway for the arrival of oxygen to every living cell. It's no secret that a well-balanced diet keeps the body and mind strong and healthy. Eating the right foods and nutrients energizes us, supports our immune system and improves our health—even our lung health!
So what happens when we have reduced lung capacity, as in the case of asthma? In brief, asthma is a chronic condition that narrows the lungs’ airways, inhibiting air flow and causing coughing and shortness of breath. Asthma’s exact cause is unknown, but many triggers can cause muscles along the air tubes to tighten and swell. Mucus production may also increase, further narrowing the breathing passages. People with asthma typically use a mix of medications (such as inhaled corticosteroids) for both long-term control and quick relief from acute symptoms. Some people’s asthma is so severe that they need hospitalization to restore normal breathing.
The right nutrients in your diet may help you breathe easier, and in some cases, help minimize asthma symptoms. While there’s no specific diet recommendation for asthma, there are some foods and nutrients that may help support lung function and reduce asthma symptoms.
How Does Food Relate to Breathing?
Metabolism is the process of changing food to fuel in the body. Oxygen is important in this process to help burn the food’s nutrient molecules. When sugars, fibers, fats and proteins are broken down, energy is the final product. Carbon dioxide is created as a waste product and is exhaled.
Different types of nutrients require different amounts of oxygen and produce different amounts of carbon dioxide. Carbohydrates use more oxygen and produce more carbon dioxide, whereas fats produce less carbon dioxide for the amount of oxygen consumed. "Some people with COPD feel that eating a diet with fewer carbohydrates and more healthy fats helps them breathe easier," says Traci Gonzales, nurse practitioner and volunteer spokesperson for the American Lung Association.
What might help
Vitamin D: Some research indicates that vitamin D plays an important role in boosting immune system responses and helps to reduce airway inflammation. Low levels of vitamin D have been linked to increased risk of asthma attacks in children and adults. Research also shows adults with asthma may benefit from vitamin D supplements, such as protective effects against acute respiratory infection. Food sources of vitamin D include: fortified milk and orange juice, salmon, and eggs.
Vitamin E contains a chemical compound called tocopherol, which may decrease the risk of some asthma symptoms like coughing or wheezing. Food sources of vitamin E include: almonds, raw seeds, swiss chard, mustard greens, kale, broccoli and hazelnuts.
Plant-based diet: It appears that people may also get some relief from asthma symptoms on a plant-based diet. The mechanisms are not entirely understood, but when a patient is looking to avoid being on an inhaled corticosteroid, another option is going on an anti-inflammatory diet, which would be a whole-foods, plant-based diet.
Whole plant foods such as vegetables, fruits (especially apples and bananas), whole grains, legumes, nuts and seeds are high in antioxidants and other phyto-chemicals that are anti-inflammatory. In addition, more fiber in the diet may help. Studies have shown that a low fiber intake is associated with reduced measures of lung function and an increased prevalence of airway restriction. Increasing fiber intake (plus a plant-based diet) feeds the “good” bacteria in the gut microbiome, which then produce anti-inflammatory compounds that can boost immunity and dampen inflammation throughout the body.
What to try and avoid
Sulfites: While some fresh fruit such as apples and bananas can be helpful in your diet, sulfites are found in many dried fruits (and some processed, packaged products) and can cause an adverse reaction or even worsen asthma symptoms for some. Sulfites are also found in some pickled food, shrimp, maraschino cherries, bottled lemon or lime juices and alcohol (especially red wine).
Foods that cause gas: Eat in moderation, foods that cause gas or bloating, which often make breathing more difficult. Such foods may cause chest tightness and trigger asthma flare ups. Foods to avoid include: beans (unless they are soaked overnight to release some of the gas-causing compounds), carbonated drinks, and fried foods.
Salicylates: Salicylates are naturally occurring chemical compounds and, although it's rare, some people with asthma may be sensitive to salicylates found in tea, coffee, some herbs or spices and even aspirin.
Dairy: People with common food allergies or sensitivities to things like dairy products, artificial ingredients, tree nuts, wheat or shellfish, may also be at risk of developing asthma. One study found that subjects with asthma experienced a decline in their pulmonary diffusing capacity for 3 hours after drinking 16 ounces of whole milk. But some research studies didn’t find a definitive connection between dairy and asthma. Another research review found that a milk component called beta-CM-7 could stimulate mucus production in the respiratory tracts of patients with actively inflamed tissues, potentially explaining why eliminating dairy then improved symptoms.
Keep in mind that food restrictions and allergies vary depending on the individual. Remember, no single food or vitamin will supply all the nutrients you need. A diet with a variety of vitamins and nutrients that keep our minds and bodies healthy. It's important to consult your doctor or a nutritionist before making any drastic changes to your diet.
Joliffe et al. October 3, 2017. Vitamin D supplementation to prevent asthma exacerbations: a systematic review and meta-analysis of individual participant data. The Lancet. https://www.thelancet.com/action/showPdf?pii=S2213-2600%2817%2930306-5
Asthma and diet: what to eat and what to avoid. April 2019. Healthline https://www.healthline.com/health/asthma/asthma-diet
Guilleminault et al. Nov 2017. Diet and asthma: is it time to adapt our message? Nutrients. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5707699/
Mayo Clinic. Asthma diet: does what you eat make a difference? https://www.mayoclinic.org/diseases-conditions/asthma/expert-answers/asthma-diet/faq-20058105
Boyer and Liu. May 12, 2004. Apple phytochemicals and their health benefits. Nutrition Journal. https://nutritionj.biomedcentral.com/articles/10.1186/1475-2891-3-5
Okoko et al. 2007. Childhood asthma and food consumption. European Respiratory Journal. https://erj.ersjournals.com/content/29/6/1161
Gililand et at. 2002. Dietary magnesium, potassium, and sodium and children’s lung function. American Journal of Epidemiology https://academic.oup.com/aje/article/155/2/125/107977