Asthma is a chronic lung disease that affects millions of people worldwide. The condition is characterized by:
- Shortness of breath
- Chest tightness
It causes the airways to become narrow, which results in difficulty breathing. A variety of factors influence the prevalence of asthma within the population. These include genetic and environmental determinants.
Specific populations show higher levels of asthma, often due to poverty, lack of available medical care, living conditions, and other circumstances that may or may not be within the control of the person who suffers.
One area that merits additional study is the effect of diet on the frequency and severity of asthmatic episodes. Understanding the impact of dietary choices on asthma within society may encourage new treatment approaches, reduce triggering factors, and improve diagnostic strategies.
What is the Relationship Between Food and Asthma?
Along with environmental factors, dietary choices also affect the prevalence of asthma. Since the mid-twentieth century, lifestyle changes and personal eating choices have contributed to an increase in asthma.
This is true even in developed nations, where one might assume that improved access to medicine would have curtailed or reduced this trend. The types of food consumed affect whether the diet promotes or reduces inflammatory properties that may lead to or increase the severity of asthmatic outbreaks.
Combined with various environmental factors, an increase in obesity, and a decline in physical activity, dietary habits have led to an increase in asthmatic bronchitis worldwide.
According to the World Health Organization, approximately 265 million people suffered the effects of asthma in 2019. Of that number, an estimated 455,000 people perished. Although non-communicable, asthma remains the top chronic disease suffered by children.
Inflammatory Foods Can Worsen Asthma Symptoms
In many developed nations, the transformation of the diet has more people consuming foods that have pro-inflammatory properties. These include:
- Refined grains
- Overly-sweetened desserts
- Processed and red meats
- Other preserved food products
People oft for a diet that emphasizes convenience and fast food rather than larger servings of fruits, vegetables, and whole grains.
Research often compares broader dietary practices among cohorts, such as analyzing the differences between asthmatic outbreaks among those who indulge in the Mediterranean diet versus the Western diet.
While generalizations can be made about more significant dietary trends, people usually do not eat a single type of diet exclusively. Other environmental factors that may also affect the prevalence of asthma include:
- Air pollution
- Exposure to tobacco smoke
- Unsanitary living conditions
- Exposure to occupational dust and chemicals
How to Choose a Diet for Asthma
When considering which foods may be helpful or hurtful, individuals should focus on the synergistic effect of all factors, including:
A person who usually eats fruits and vegetables may occasionally indulge in a greasy hamburger, fries dripping with grease, and an overly-rich shake.
However, understanding one’s dietary patterns will provide an individual with a better assessment tool rather than trying to pigeonhole themselves into a single, narrowly defined category.
Asthma Diet: Foods That Can Help
Scientists believe that there are two diets that may benefit those who suffer from asthma symptoms. This includes:
- Mediterranean diet
- Plant-based diet
Mediterranean Diet for Asthma
Studies began to focus on the benefits of the so-called “Mediterranean diet” more than fifty years ago. In places such as Greece and Italy, the combination of fruits, vegetables, omega-3 fatty acids from fish, and whole grains was considered essential factors in the region’s lower coronary heart disease rate.
Mediterranean dietary practices generally differ from the consumption of high-fat, fast-food dishes that are frequently made from food items that are heavily processed or loaded with preservatives.
Often locally harvested and seasonally fresh, most Mediterranean diets have foods that experience only minimal processing. These diets include fewer dairy products and red meat. Instead, they focus on:
- Olive oil
In fact, olive oil serves as the primary source of supplemental fat for many prepared dishes. Abundant consumption of fruits and vegetables adds fiber, minerals, vitamins, and antioxidants to the body. In addition, fruits and vegetables that are minimally processed have fewer preservatives or sulfites.
Overall, the Mediterranean diet has lower levels of trans fats and omega-6 fatty acids, with fewer average servings of animal products that tend to increase or exacerbate incidents of asthma.
Plant-Based Diet for Asthma
Plant-based diets low in saturated fat focus on fruits, vegetables, legumes, and grains that reduce inflammation. A vegan or vegetarian diet has high fiber levels that improve both lung function and the gut microbiome, which reduce the potential for aggravated airway diseases.
Even those who have suffered from asthma in the past have experienced less frequent and not-as-severe asthma symptoms by embracing a plant-based diet.
Foods That May Reduce Asthma Symptoms
- Fruits and vegetables
- Citrus fruits
- Leafy greens
- Beans and legumes
1. Fruits and Vegetables
A diet rich in fruits and vegetables has been found to lower the risk of developing asthma in both children and adults. The consumption of fresh fruits and vegetables may reduce swelling in the lungs caused by oxygen-derived free radicals.
The benefits vary based on the vitamins, minerals, and antioxidant properties of individual fruits and vegetables. I’ll mention several below due to their documented clinical studies, but a few others to consider include:
- Cantaloupe: Rich in vitamins A and C, with powerful antioxidants
- Carrots: Beta-carotene is converted into vitamin A by your body
- Guava: A great source of vitamin C that aids your immune system
- Pomegranates: An antioxidant-rich option that may lower airway inflammation
Consumption of apples and the phytochemicals within them improves pulmonary health and reduces the effects of asthma, according to a study.
Physicians have known about the benefits of the high antioxidant activity of apples for many years. A separate study that focused on adult asthma and dietary antioxidants also touted the positive benefits of a diet that includes apples.
3. Citrus Fruits
A diet rich in citrus fruits promotes a reduced risk of asthmatic outbreaks. Those prone to asthma symptoms who have higher levels of vitamin C intake and citrus fruit consumption have noticed decreased risk over a period of time.
4. Leafy Greens
Leafy green vegetables are rich in vitamins and minerals, including folate. Diets with deficiencies in folate and vitamin D have been shown to increase the number of asthma attacks, according to a study.
Other thoracic studies have confirmed the value of leafy greens in reducing stress during respiration.
Low in calories, tomatoes also have beneficial antioxidants. A 2006 study on how the intake of fruits and vegetables affects the prevalence of asthma in adults indicates that a diet rich in tomatoes has beneficial effects.
Tomato juice, with lycopene as an antioxidant, is also believed to help open the airways, making it easier to breathe.
6. Beans and Legumes
Rich in prebiotics that feed healthy gut bacteria, beans and legumes play a role in lowering the risk of asthma and other inflammatory disorders. Prebiotics in beans and legumes allow the gut bacteria to thrive.
A study examining characteristics of the gut microbiota in limiting autoimmune diseases emphasized the importance of a diet rich in beans and legumes as a way to control the effects of inflammation.
Commonly used in Indian and South Asian foods, turmeric has served medicinal purposes in Asia for thousands of years. The primary active compound in turmeric is curcumin, which has anti-inflammatory properties that may alleviate airway inflammation.
A study focusing on those suffering from bronchial asthma determined that curcumin capsules offered a safe and effective add-on therapy.
This turmeric product provides better nutrient absorption to help you get more of the benefits.
Commonly used to relax an upset stomach, ginger has similar effects on the airway smooth muscle (ASM).
A study confirmed the beneficial effects of ginger on the airways. Adding fresh ginger root to already-heathy dishes, such as wild rice and vegetable stir-fry, is an excellent way to get the benefits of this root.
As one of the best sources of vitamin D, salmon is an excellent protein choice that’s packed with healthy fats and antioxidants. Not to mention, the omega-3 fatty acids in fatty fish are known for reducing inflammation.
A study of over 7,400 French schoolchildren published in 2015 reaffirms the importance of a diet with fish in lowering the incidence of asthma. Fatty fish is packed with omega-3 that lowers the potential for inflammation; therefore, salmon remains a top choice.
Flaxseeds are high in fiber, antioxidants, and omega-3 fatty acids. As previously mentioned, research indicates that omega-3 fatty acids play a role in lowering inflammation and asthma outbreaks.
Unfortunately, most adults eat foods rich in omega-6 fatty acids, which can make asthma symptoms worse. However, these adverse effects are offset by foods high in omega-3 fatty acids, such as salmon and flaxseeds.
Asthma Diet: Foods to Avoid
While there are many healthy foods that may help to prevent or alleviate asthma symptoms, there are also some foods that can make symptoms worse. Unfortunately, many of these foods are very common in the average diet.
Effects of the Western Diet on Asthma
Most research on the increasing prevalence of asthma discusses the growing popularity of the so-called Western diet. Residents of the United States and many developed nations tend to eat fewer vegetables, fruits, legumes, and whole grains than they did in earlier generations.
In their place, these populations have increased their consumption of animal products. The result of these eating practices is the ingestion of excessive amounts of saturated fat and far fewer servings of fruits and vegetables than recommended.
The prevalence of asthma tends to increase in cultures that embrace the Western diet. Understanding the basic elements of Western dietary practices illustrates the underlying factors of this increase in asthma attacks and how public health and medical interventions should respond.
The Western diet emphasizes the convenience of processed and preserved foods, as well as readily available fast food selections. This includes:
- Fried foods
- Sweets and desserts
- Refined grains
- Processed and red meats
- High-fat dairy products
These often have higher levels of sugar, sodium, omega-6 fats, and saturated fat. With a reduced emphasis on fruits and vegetables, this diet has lower levels of antioxidants, micronutrients, phytochemicals (such as flavonoids), fibers, and omega-3 fatty acids.
This combination of low fiber intake and higher amounts of bad fats tends to increase airway inflammation, negatively impact lung function, and increase the potential for frequent asthmatic episodes.
Foods That May Worsen Asthma Symptoms
For people with asthma, some foods and drinks have properties that can make asthma symptoms worse. Some examples include:
- Fast food
- Trans fats and Omega-6 fatty acids
- Foods high in sulfites
- Dried fruits and vegetables
- Pickled fruits and vegetables
- Alcoholic beverages
- Processed meats
- Dairy products
1. Fast Food
While lumping many items under the fast food umbrella offers a generalized statement, research has indicated that consuming high amounts of saturated fat and low amounts of fiber causes airway inflammation.
Therefore, it makes sense why people who eat a lot of fast food tend to experience worse asthma symptoms than those who don’t.
2. Trans Fats and Omega-6 Fatty Acids
Trans fats and omega-6 fatty acids, which are often found in processed foods, can also cause inflammation. They are believed to have a deleterious effect on heart health and may increase the incidence of asthma.
Not to be confused with omega-3 fatty acids, which have anti-inflammatory properties, omega-6 fatty acids are pro-inflammatory. This means that they can have the opposite effect of omega-3s and make asthma symptoms worse.
3. Foods High in Sulfites
Sulfites frequently appear in food products as a common type of preservative. According to the Asthma and Allergy Foundation of America, sulfites consumed in large amounts and for prolonged periods may trigger asthmatic episodes.
Sulfites have also been shown to have an adverse effect on the growth of gut bacteria that is beneficial to digestion. Therefore, it’s important to examine food labels to become aware of your favorite products that contain sulfites. This includes everything from packaged potatoes to bottled lemon and lime juice.
4. Dried Fruits and Vegetables
While fresh fruits and vegetables contain healthy doses of antioxidants, vitamins, and minerals, the drying process often diminishes these levels. Dried fruits and vegetables also tend to be high in preservatives, which can make asthma symptoms worse.
Despite the fresh appearance, those raisins in your trail mix may actually be doing more harm than good regarding your asthma. Next time you’re at the grocery store, try to choose fresh fruits and vegetables over their dried counterparts.
Dishes that include large amounts of vinegar also contain high levels of natural sulfites from the fermentation process.
Although some claim that apple cider vinegar actually helps reduce the effects of asthma, this remains a topic of great debate and speculation as a home remedy. Similar to other foods with high levels of sulfites, moderation is important.
6. Pickled Fruits and Vegetables
Similar to dried fruits and vegetables, the pickling process, which also involves vinegar, is characterized by high levels of sulfites that may worsen asthma symptoms. This includes:
- Pickled cucumbers
Again, while these foods might make a great addition to your favorite sandwich, they may do more harm than good regarding your asthma. Therefore, consider limiting your intake or avoiding these foods altogether.
Shellfish is one of the most common food allergens and can trigger a severe reaction known as anaphylaxis. Not to mention, it’s yet another food type that contains sulfites.
Researchers found a link between allergens and asthma; therefore, it may be best to avoid shellfish and other trigger foods if you have asthma.
8. Alcoholic beverages
While a glass of wine or beer with dinner may seem harmless, alcohol has been shown to negatively affect those with asthma.
Again, thanks to sulfites.
The fermentation process of alcoholic beverages creates sulfites as a natural byproduct. Various wine brands claim they are “sulfite-free,” but some residual sulfites are most likely present.
9. Processed meats
Processed meats, such as bacon, sausage, and ham, are high in sodium and saturated fat. These are known for increasing inflammation throughout the body, including the airways of the lungs.
Studies have linked worsening asthma symptoms to diets that include large amounts of cured meat.
Researchers also found that eating processed meat was linked with an increased risk of chronic obstructive pulmonary disease (COPD). This condition is similar to asthma in that it makes breathing difficult.
10. Dairy Products
According to the Physicians Committee for Responsible Medicine, excessive dairy consumption in children led to an increased probability of developing asthma.
In addition, a study in children found that increased consumption of butter along with fast food led to a greater prevalence of asthma.
Therefore, refraining from dairy products makes sense, especially for those who are sensitive to lactose. If drinking milk-based products increases phlegm or feelings of congestion, you may consider avoiding it altogether.
How Do Food Allergies Affect Asthma?
A food allergy is an immune reaction to a food protein that the body perceives as a threat. The reaction may be mild, such as an itchy feeling in the mouth, or more severe, such as difficulty breathing.
People who suffer from food allergies should avoid consuming any triggering foods because they can worsen asthma symptoms. Some common food allergens include:
While these are some of the most common food allergens, others do exist. If you think you may have a food allergy, it’s important to talk to your doctor. This is especially true if you also have asthma.
Can the Foods You Eat Affect Asthma Symptoms?
The type of food and drink a person consumes, along with the amount, may impact the prevalence of asthma symptoms they experience. High-calorie diets lead to weight gain and potential obesity, which may lead to asthma.
Some people may experience temporary asthma symptoms due to their sensitivity to sulfites used as preservatives.
Many people who live with asthma also suffer from Gastroesophageal Reflux Disorder (GERD). This results in stomach acid reflux, which makes it more difficult to manage asthma symptoms. Therefore, dieting and avoiding foods that cause GERD symptoms may improve the condition.
What is the Best Diet for Reducing Asthma?
Each person has unique dietary preferences. Some have allergies to foods that may otherwise be beneficial. A diet with more fruits and vegetables reduces the risk of asthmatic bronchitis.
No single diet will gain universal acceptance, so individuals should develop one that includes a more significant proportion of anti-inflammatory foods that best suit their tastes.
Is a Plant-Based Diet Good for Reducing Asthma?
A plant-based diet reduces the intake of dairy products, high-fat meats, and overly-processed or chemically-preserved foods that tend to promote inflammation.
Whether vegan or vegetarian, focusing on plant-based foods improves airflow and reduces inflammatory responses to foods.
Is the Paleo Diet Good for Asthma?
This nutrition-dense diet is focused on balancing items from a variety of food groups without indulging in empty calories and refined or processed foods. Although no conclusive studies have directly connected a dedicated Paleo diet to reduced asthmatic incidents, many of the foods consumed in this diet are thought to be beneficial.
High-fiber Paleo diets may help suppress inflammation in the airways. This is due to the short-chain fatty acids created as fiber, which are metabolized by gut microbes.
Therefore, you may opt for food sources with high amounts of fermentable fiber, such as legumes and beans, as well as bananas, barley, and oats.
Asthma and Diet: Conclusion
Although the consumption of certain foods affects airway inflammation, no single diet will address all asthma concerns. Despite the many research studies conducted on the etiology of asthma and the effects of certain foods, many questions remain.
General recommendations in scholarly literature encourage increased consumption of fruits and vegetables, coupled with the reduced intake of dairy products, saturated fats, and processed foods.
Therefore, the dietary decisions you make can modify your asthmatic risk factors.
Read our full guide on the best foods for lung health to learn more. Thanks for reading, and, as always, breathe easy, my friend.
John Landry is a registered respiratory therapist from Memphis, TN, and has a bachelor's degree in kinesiology. He enjoys using evidence-based research to help others breathe easier and live a healthier life.
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