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Foods: What to eat (and what nutrients you need) for healthier lungs

Foods to eat foods to avoid

Your daily diet plays an important role in whether you’ll get an asthma flare-up or not. Follow this nutritionist-approved guide for better health—and breathing.

There’s no question that eating a healthy diet rich in nutritious whole foods boosts overall health. While no one person is the same in terms of the types of foods they can and can’t tolerate, there are some basic foods that have been shown to help keep the lungs healthy, reducing the symptoms of asthma. These include straight-from-nature whole, not processed, foods like fruits and vegetables, whole grains, nuts and seeds, and healthy fats. As asthma is a chronic inflammatory disease, a healthy whole foods diet works, say researchers, by reducing overall inflammation in the body—and in the lungs. (For more information about inflammation, see page 18 in the Healthful Living Magazine.)

“Inflammation is a normal response of the immune system,” says Tina Marinaccio, MS, RD, CPT, Healthful Living’s Integrative Culinary Registered Dietitian. In the case of asthma, however, the immune system is constantly sending out messages to trigger inflammation in the airways and in the lungs—which can become chronic over time. “We know,” says Marinaccio, “that we can reduce this inflammation that causes asthma by adding specific foods into the diet.”

The Power of Plants

Phytonutrients are natural chemicals found in plants that help protect them against fungal, bacterial, and viral infections. These phytonutrients, or phytochemicals as they’re sometimes called, give plants, fruits, and vegetables their bright colors. When we eat these foods, we get not only important nutrients but also these powerful, protective phytonutrients too. What’s more, these phytochemicals can be indirectly protective as well. In one Dutch study, researchers found that pregnant women who ate apples regularly (apples are high in phytonutrients) gave birth to children who were less likely to suffer from asthma and wheezing by age five.

Flavonoids are the main category of phytonutrients found in all plants. These are some flavonoids that can be particularly helpful to those who suffer from asthma:

Anthocyanins (ann-though-SIGH-a-nins) are found in purple and blue foods like grapes and berries. They help reduce inflammation in the body, including in the lungs, and keep the lungs healthy over time.

Carotenoids (ker-ahh-TEN-oids) are found in orange and red foods such as sweet potatoes, mangoes, and carrots. These phytochemicals help reduce overall inflammation. Also, people who suffer from asthma have been found to be deficient in these particular phytonutrients, why getting enough in your daily diet may help reduce symptoms.

“Unlike fast-acting medications, anti-inflammatory phytonutrients take time to build up in the body. You’re not going to eat one apple and see your symptoms go away. You really have to give it a few months, so the body can bolster its stores. That’s when you should really start to notice a difference.”  – Tina Marinaccio, MS, RD, CPT

Quercetin (kwhere-SE-tin) a yellow-hued phytonutrient, can be found in onions and apples, among others “Quercetin has been shown to decrease inflammatory histamine in the body,” explains Marinaccio. “This helps reduce asthmatic symptoms like wheezing.” (Quercetin has also been shown to help reduce the symptoms of COVID-19.)

Hesperidin (hess-PAIR-e-din) is the plant chemical most concentrated in citrus fruits like lemons and oranges. It’s been shown in studies to help reduce the airway inflammation associated with asthma.

When it comes to phytonutrients, getting a wide variety of them in your diet every day is key. “There are over 100,000 phytonutrients in plants,” Marinaccio explains. “It’s easy to get stuck on one ‘superfood’ or panacea, but we need a mix of plants in our daily diet. Instead of focusing on one food, commit to eating a variety of phytonutrients every day.”

How Fermented Foods Can Help

The gut, or microbiome as it’s sometimes referred to, plays an important role in how our immune system works. In fact, 70 percent of immune cells are found in the gut. It makes sense then that if the gut is unhealthy, the immune system won’t be healthy either. This link between the two is referred to the “gut-immune axis,” says Marinaccio.

One thing critical to a healthy gut-immune axis is having enough good-for-you bacteria in the gut. This bacterial buildup in the microbiome begins at birth, and it’s become widely accepted, says Marinaccio, that children should be exposed to a range of bacteria from the time of birth for better health. This “hygiene hypothesis,” as it’s called, says lack of exposure to bacteria doesn’t allow newborns the opportunity to develop optimal gut microorganisms. This is why it’s believed that children who aren’t exposed to myriad bacteria have a greater tendency to develop eczema, allergies, and asthma in childhood and adulthood. One study, for example, found that one-year-olds with an imbalanced gut have an increased risk of asthma at age five.

food in glass containers

“Without enough exposure to germs at an early age, our immune system doesn’t get educated on how to properly respond when it comes into contact with bacteria and potential allergens like dust,” explains Marinaccio. “There’s also not enough desirable gut bacteria to keep our immune system functioning optimally.” Without the right kinds of bacteria in our gut, the immune system can trigger inflammation—and symptoms of asthma.

One of the best ways to get these good bacteria into the gut is through fermented foods. “Fermented foods help build up the fortress of good bacteria in your gut,” explains Marinaccio. As with phytonutrients, the more variety of fermented foods you can get in your diet, the better for overall balance in the microbiome.

Fermented foods include tempeh (a nutty-flavored, soy-based “cake”), kombucha (fermented green or black tea), miso, and kimchi (made from fermented, salted cabbage and radish). Sauerkraut and pickles sold in the refrigerated section are also fermented. (Those sold in non-refrigerated aisles don’t contain healthy bacteria or probiotics.) Cultured dairy, if you can eat dairy, also contains healthy bacteria. This includes kefir (a thick yogurt-like drink) and yogurt.

So-called “prebiotic” foods are also important to include in your diet. These foods, such as oats, asparagus, Jerusalem artichokes, leeks, onions,and legumes, contain fiber that provide food for healthy bacteria.

Key Nutrients You Need

All nutrients are important for a healthy body and immune system, but there are some that have been shown to help improve lung health and reduce asthma symptoms. The best source for these nutrients is food, unless your doctor advises otherwise.

leafy greens illustration

Magnesium is a nutrient critical for lung function. It’s been shown to help improve breathing. Levels of this nutrient have been found to be lower in those with asthma, and a deficiency has been seen in some people with severe asthma. Some researchers believe that inadequate amounts of magnesium in the body may cause a buildup of calcium in the muscles lining the airways of the lungs. This buildup can cause the airways to constrict, making breathing more difficult.

Good Sources dark chocolate with at least 70 percent cocoa or cacao, avocados, nuts, legumes like lentils and black beans, and seeds like pumpkin, flax, and chia.

Potassium is a nutrient that helps the lungs to expand and contract and may help decrease wheezing. A deficiency may contribute to shortness of breath. In fact, one study from the University of Southern California found that children who don’t get enough potassium and magnesium in their diets have lower lung function (a measure of how well their lungs work).

Good Sources  avocados, oranges, leafy greens, pinto beans, and bananas

Omega-3 fatty acids gained interest by researchers who observed low rates of asthma among Eskimos, who eat large quantities of oily fish that are rich in these essential fatty acids. Omega-3 fatty acids are known anti-inflammatories and seem to reduce the production of IgE, antibodies that cause allergic reactions and asthma symptoms. (See page 21.) In one study, children who had a higher dietary intake of omega-3 fatty acids had less risk of developing asthma as they got older.

What’s more, high levels of omega-6 fatty acids—prevalent in processed, packaged foods with refined oils like soybean and corn oil—are associated with more severe asthma. “The typical American diet has three times the amount of omega-6 fatty acids that we should be eating,” explains Marinaccio. “We should all be decreasing foods with omega-6 fatty acids and eating more foods with omega-3 fatty acids.”

Good Sources oily, fatty fish (like salmon, mackerel, and sardines), cod liver oil, and seeds like flax and chia

Vitamin A  is essential for immunity, as well as healthy lung functioning. Low levels of vitamin A have been associated with more frequent respiratory infections, while higher blood levels of this nutrient have been linked to better lung function.

Good Sources liver, salmon, carrots, broccoli, cod liver oil, kale, spinach, cantaloupe, and sweet potatoes

Because excess vitamin A can get stored in the body, you need to be careful about supplementing with vitamin A, which—if you get too much—can be toxic. Talk to your doctor about what your body needs.

yellow pepper

Vitamin C is a natural antihistamine, which means that it’s able to block histamines, the compounds in the body that trigger allergy and asthma symptoms. It’s also an anti-inflammatory. It seems to help reduce inflammation in the body and particularly in the airways. Vitamin C has also has been shown to reduce the risk of viral respiratory infections in those with asthma.

Good Sources oranges, grapefruit, strawberries, acerola cherries, sweet yellow peppers, thyme (which has the greatest concentration of vitamin C of all culinary herbs), parsley, kale, kiwis, broccoli, and papayas

woman running illustration

Vitamin D may help reduce the number of asthma attacks and keep the lungs healthy, say researchers. It makes sense, then, that vitamin D plays an important role in immune and respiratory health—a key reason that it was recommended as a supplement to help prevent and mitigate the symptoms of COVID-19.

One of the best ways to get enough vitamin D is through about 15 minutes of unprotected exposure to sunlight (the skin converts sunlight to a form of vitamin D the body can use). People with darker skin need two to three times the sun exposure to make enough vitamin D. During the winter months, however, it’s hard to get enough vitamin D in this way.

Good Sources salmon, fortified milk, fortified orange juice, and eggs

Talk to your doctor about whether you should have your vitamin D levels tested—and whether supplementation (and sunscreen) makes more sense for your health.

Vitamin E has anti-inflammatory properties like vitamin C. Some studies have shown that a type of vitamin E called gamma tocopherol may help reduce airway inflammation in asthma patients. Researchers found that people with high levels of this vitamin in their diets were less prone to asthma.

Good Sources nuts like walnuts and pistachios. For those who are sensitive to tree nuts, ground flaxseeds (better digested than whole seeds) and pumpkin seeds are also good.