Asthma

Asthma, a condition that strikes the small air passages of the lungs in episodes called asthma attacks, affects the lives of many people in this country.

Asthma attacks occur when smooth muscle cells clamp down on air passages, closing them off. This makes it much harder to get air in and out of the lungs, leading to wheezing and difficulty breathing. If the attack continues, the patient may pass out or even die from suffocation.

Although asthma patients may be symptom-free between attacks, they must live with the fear that another asthma attack may happen at any time. Fortunately, healthy food choices may help reduce attacks and alleviate symptoms caused by this debilitating condition.

Eat more

  • Organically grown fruits and vegetables
  • Cold water fish including cod, salmon, mackerel, herring and halibut
  • Extra virgin olive oil
  • Flax seeds
  • Rosemary, ginger and turmeric

Eliminate milk and other dairy products which have been most commonly cited as increasing the severity of asthmatic symptoms.

Description

What Is Asthma?

Researchers estimate that as many as 10-15% of children in the United States live with asthma, and the numbers are rising. Roughly 40% of cases are estimated to be mild cases, and around 50% are estimated to be moderate cases.

Unfortunately, as many as 10% of all cases are considered very severe. Very severe asthma which does not respond quickly to medicine can lead to time in the hospital, emergency room visits, and, in some cases, death. This condition not only threatens the lives and well-being of many children, young adults, and even adults in this country, it can also put serious limitations on normal living, something that others take for granted.

Asthmatic patients may be unable to participate in sports, may have trouble sleeping because of symptoms, and may need to take medications that have negative side effects such as weight gain, fatigue, and susceptibility to infections. They live with the fear and anxiety of knowing that they may experience another asthma attack at any time. The good news is that there are ways, through healthy dietary changes, to prevent the incidence of asthma or to lessen the symptoms of this sometimes debilitating condition.

Symptoms

Asthma predominantly occurs in periods called asthma attacks, when the symptoms are the worst. Between these attacks, patients may have mild symptoms or no symptoms at all. The main goal of standard medical treatment is to prevent these attacks and also to make them end quickly when they do occur.

Some symptoms of asthma, especially during an asthma attack, include:

  • Shortness of breath or difficulty breathing
  • A feeling of tightness or pain in the chest
  • Rapid shallow breathing that may be easier when sitting up
  • Wheezing especially while breathing out
  • Coughing at night or after an attack, producing thick mucus
  • Inability to speak
  • Exhaustion
  • In rare and extreme cases Ė collapse and suffocation

Most asthma patients require medication during an attack to help them breathe again. Following an attack, patients may go through a spell of coughing up a lot of mucus and phlegm. In general, asthma attacks are frightening experiences where the simple act of breathing seems like the most difficult task in the world.

Note: Asthma is a very serious and potentially deadly condition. It's important to realize that the dietary and nutritional information presented in this section is not meant to replace medical treatment. Asthma patients are encouraged to try the dietary changes recommended, but must realize that these guidelines are not a substitution for prudent medical care. We encourage asthma patients to continue taking their medications as needed and to continue to be supervised by their doctors.

The Disease Process

What happens in the lungs of asthma patients to bring on these awful asthma attacks? In normal lungs, the small air passages are surrounded by smooth muscle cells. These cells work to keep the air passages open so that air can move freely in and out of the lungs during breathing.

The passages are lined by another type of cell, called endothelial cells, which produce a slippery fluid called mucus. This mucus can trap things like dust and bacteria that wind up in the lungs. Mucus also helps lubricate the passages, which protects the cells of the lungs from being dried out and irritated by air that is constantly flowing through the air passages.

When an asthma attack strikes, however, these cells malfunction. Instead of being relaxed, the smooth muscle cells start to contract and tighten around the air passages, closing them off. The endothelial cells start to make a very thick and sticky type of mucus.

Air cannot flow in and out of the lungs easily and may get trapped inside the lungs, causing wheezing, especially when trying to push out the trapped air. The thick mucus also gets stuck inside the air passages and can block them even more. As more and more passages get closed off and blocked, it gets harder and harder to breathe.

If the attack continues for too long, the lack of air may cause unconsciousness or even death due to suffocation. If the asthma attack does stop, typically through the use of inhaled medication, the smooth muscle cells relax again and the air passages reopen to allow life-giving air to once again flow in and out of the lungs.

Unfortunately, attacks typically end with a lot of coughing as patients must now get out all of the sticky mucus that was blocking the airways during the attack. In the end, the patient is able to breathe again, although usually exhausted from the experience, and the cells in the lungs go back to doing their normal tasks.

Causes

The rates of asthma around the world have been going up at a remarkable speed lately. The number of people affected by asthma is now more than twice what it was back in the early 1980s, and the number of children with asthma is now three times what it used to be. Researchers believe that this rapid increase is due to several factors, including air pollution, allergies, and changes in dietary habits.

Air pollution, which has also increased with time, has been shown to irritate the lungs, leading to a process called inflammation. The air passages normally contain some cells of the immune system, which defend the lungs against infections. In asthmatic patients, however, these cells seem to be hyperactive.

When chemicals, like cigarette smoke or car exhaust, aggravate these hyperactive immune cells, they go out of control, producing substances called prostaglandins, leukotrienes, and histamine, which aggravate even more hyperactive cells. Hyperactive cells also produce large amounts of free radicals. These free radicals not only cause more inflammation, they also irritate smooth muscle cells, causing them to constrict, and endothelial cells, causing them to produce the more sticky mucus.

Allergies play a big role in the condition for most asthma sufferers. An estimated 80% of asthma patients have allergies. Allergies have also been on the rise lately, though researchers are not quite sure why. Some believe it is due to the fact that, because of city-living, vaccinations, antibiotics, and antibacterial cleaning products, children are not being exposed to the plants, bacteria, and viruses that are needed to support the healthy development of the immune system. Studies show that children who grow up on farms, where they are exposed to more pollen, grasses, dirt, and bacteria, actually have less allergies than children who grow up in cities.

Being allergic to things like dust or animal fur can be a real problem for asthma patients. When they breathe in the substances they're allergic to, the hyperactive immune system overreacts, which leads to lung inflammation and an asthma attack. Many medical treatments for asthma currently focus on blocking the actions of these immune cells, so that they won't react to allergens in the air. Unfortunately, these treatments often have undesirable side effects, such as fatigue and weight gain.

Dietary habits are also being blamed for the increase in asthma rates. When populations around the world switch from a traditional diet high in fruits, vegetables, and fish to one high in salt and vegetable oils, and low in plant foods, the rate of asthma tends to go up.

Certain dietary habits can help reduce the hyperactivity of the immune cells so they're less reactive to air pollution and allergens. Certain nutrients can also help neutralize the free radicals produced, which may reduce the severity or frequency of asthma attacks and improve the function of the lungs. Still other changes can keep the smooth muscle cells from contracting and closing off the airways. Put together, dietary changes can have a positive impact in the lives of many people currently suffering from asthma.

Dietary Causes

Multiple dietary habits are believed to have contributed to the remarkable rise in the amount of asthma in this country. Diets high in the omega-6 fatty acids found in farm-raised meats, vegetable oils, and margarine, and those high in table salt and salty foods have been associated with increased rates of asthma.

In addition, many asthma patients have been shown to react to artificial food additives or preservatives, such as MSG (monosodium glutamate), yellow dye #5 (tartrazine), and sulfites. Eating these chemicals in processed foods may trigger asthma attacks.

Adverse food reactions may be yet another contributing factor in asthma. Approximately 66% of asthma patients report that certain foods make their asthma worse. The most commonly cited foods are dairy products, such as milk and cheese, followed by eggs. For some patients, eliminating these foods from their diets has greatly reduced symptoms.

Some patients find that a different food, or multiple foods, contributes to their condition. An allergy elimination diet may be helpful in determining if adverse food reactions are part of the problem.

Although itís too late for most asthma patients, it may be possible to reduce childhood risk of developing asthma simply by breast-feeding children while they're infants. Studies indicate that the risk for asthma may be due to reduced rates of breast-feeding.

Breast milk contains substances called antibodies that encourage the healthy development of the babyís immune system. In addition to providing the perfect blend of protein and nutrients for growing babies, breast milk also reduces their chances of having to suffer from allergies and conditions like asthma.

Fortunately, research has also identified several dietary habits and nutrients that may alleviate symptoms of asthma in both children and adults. Nutrients such as magnesium, selenium, and omega-3 fatty acids, as well as the antioxidants vitamin C, vitamin E, and beta-carotene, may improve the normal function of the lungs.

In addition, foods such as fresh fruits and vegetables, cold water and oily fish, olive oil, and certain spices like rosemary, have been associated with reduced rates of asthma.

Nutrient Needs

Important Note

While we hope that some of these suggestions may help improve your condition, we advise you to continue to be monitored by your doctor and continue taking any necessary medications.

Foods That May Help Include:

Fruits and Vegetables

How does a hot plate of steamed, brightly-colored vegetables followed by a big bowl of sweet fresh fruit sound? In regions where people eat a diet rich in fresh fruits and vegetables, asthma occurs much less frequently.

One study showed that lung function declines in the winter when people eat less fruit compared to summer. Other studies have associated reduced lung function with a diet low in fruits and vegetables. Fresh produce is high in many nutrients that help the lungs, including vitamin C, vitamin E, selenium, and beta-carotene.

Fruits and vegetables also contain plenty of bioflavonoids, which can help to reduce free radicals in the body. Quercitin, which is found in high quantities in yellow onions, apples, and tea, has been shown to be especially good at combating free radicals.

Two other important foods are garlic and onions, which also contain substances with powerful antioxidant activities. These vegetables may not only help get rid of the free radicals that contribute to asthma, they are also a zesty addition to a healthy diet.

Fish

How about a hot, juicy, pink salmon steak to go with those vegetables? Studies have shown a strong link between eating fish and lower rates of asthma. In Australia, children who ate just two servings of fish, including tuna, sardines, and salmon, per week had less than one third the risk of developing asthma than children who did not.

Fish, particularly cold water fish like salmon, cod, mackerel, herring, and halibut, and oily fish like sardines and tuna, are an especially important source of omega-3 fatty acids, which help reduce inflammation in the lungs.

They're also a healthy and tasty source of protein. Replacing a char-burned burger, which may be high in pro-inflammatory fats as well as other harmful chemicals, with a good-sized serving of baked, fresh halibut fillet is an excellent way to restore the balance of essential fatty acids in your body.

Rosemary

How about fresh rosemary sprinkled on top of that juicy baked salmon steak? Even rosemary may help with asthma symptoms. Most spices that are in common use today were chosen many, many years ago for their healing properties as well. Rosemary is no exception.

Today we know that rosemary is high in a substance known as rosmarinic acid, which has several actions that are beneficial in asthma. In addition to its antioxidant abilities to neutralize free radicals, rosmarinic acid has been shown to block the production of pro-inflammatory chemicals, such as leukotrienes.

It also encourages cells to make substances called prostacyclins that keep the airways open for easy breathing. Other spices like peppermint, sage, and oregano, also contain rosmarinic acid. These spices added to vegetable dishes or sprinkled on top of baked fish contribute to making meals that are not only delicious but healthy.

Olive Oil

And how about a mixed greens salad drizzled in pure extra-virgin olive oil and balsamic vinegar to start out the meal? In areas of the world where people still consume traditional Mediterranean cuisine, asthma rates are very low. It's believed that generous use of olive oil is related to the low risk of asthma.

The fats in olive oil, while showing fewer anti-inflammatory properties than high omega-3 oils like fish oil, have stronger anti-inflammatory properties than other widely-used vegetable oils like corn or safflower oil. Replacing these vegetable oils and other types of fats with pure, extra-virgin olive oil may help reduce the symptoms of asthma.

However, heating olive oil at high temperatures, as in baking or frying, can damage the beneficial fats. Olive oil should instead be used in salad dressings, or for dipping fresh-baked breads, etc.

Nutrients In Food That May Help Include:

Omega-3 Fatty Acids

Omega-3 fatty acids are fats needed by the body for healthy function. Studies show that populations who get a good supply of omega-3 fats in their diets have much lower rates of asthma, in some place as much as 70% less.

When cells have enough omega-3 fatty acids available, they produce substances that naturally reduce inflammation. When omega-3 fats are scarce, they produce substances which increase inflammation, and which could add to the occurrence or severity of asthma attacks.

In fact, increasing omega-3 fat intake has been shown to improve lung function in asthmatic patients, though it may take several months of eating more omega-3s to see a big difference in symptoms. Food sources of omega-3 fatty acids include flax seeds and cold water fish, like salmon, cod, and halibut.

Magnesium

Magnesium, a mineral needed for healthy smooth muscle cells, helps smooth muscle cells stay relaxed and not constrict. Unfortunately, many asthma patients donít get enough magnesium in their diets.

Intravenous magnesium, injected directly into the bloodstream, has been shown to save lives when used in emergency rooms for patients whose asthma attacks will not respond to other medications. Fortunately, there are much easier ways to get magnesium.

Magnesium is found in a variety of whole, healthy foods. Chard and spinach are two excellent food sources of magnesium.

Vitamin C

Vitamin C is referred to as an antioxidant. One of its basic jobs is to circulate around the body finding free radicals. When it finds these free radicals, it neutralizes them so they canít do any damage.

Since free radicals are responsible for causing smooth muscle contraction and airway constriction in asthma, having extra vitamin C on hand can really be helpful. Vitamin C also helps in the breakdown of histamine, one of the inflammatory chemicals produced by the hyperactive immune cells, and is needed for the healthy function of the immune system.

Studies have shown that people with low levels of vitamin C in their diets are at a much greater risk, as much as five times greater, of reacting to pollutants in the air. Eating foods that supply plenty of vitamin C can help to improve the general function of the lungs.

Excellent food sources of vitamin C include broccoli, parsley, bell peppers, strawberries, cauliflower, lemons, romaine lettuce, mustard greens, Brussels sprouts, papaya, kale, cabbage, spinach, kiwifruit, cantaloupe, oranges, grapefruit, tomatoes, chard, collard greens, raspberries, peppermint leaves, asparagus, celery, fennel bulb, pineapple, and watermelon.

Vitamin E

Vitamin E is another antioxidant that works to neutralize free radicals in the body. While vitamin C works to reduce the water-soluble free radicals, vitamin E works mainly on the fat-soluble ones. People who get more vitamin E have a lower risk of developing asthma. Increasing vitamin E intake has also been shown to improve lung function significantly. Mustard greens, chard, turnip greens and sunflower seeds are a few excellent sources of vitamin E.

Carotenoids

The carotenoid beta-carotene is another fat-soluble antioxidant like vitamin E. It also spends a good bit of its time finding and neutralizing free radicals. People who eat a diet that is low in beta-carotene or the vitamin that can be made from it (vitamin A) tend to be at a greater risk for asthma symptoms.

Excellent food sources of vitamin A/beta-carotene include sweet potatoes, carrots, calf liver, kale, winter squash, collard greens, chard, cantaloupe, mustard greens, romaine lettuce, spinach, parsley, cayenne pepper, peppermint leaves, Brussels sprouts, tomatoes, broccoli, asparagus, and apricots.

Lycopene, another carotenoid well known for its antioxidant activity, may also benefit those with a specific type of asthma, notably exercise-induced asthma(EIA). Researchers studying 20 EIA patients found that 55% of those who received a lycopene-supplemented diet had significant protection against EIA compared to those receiving a placebo.

Food sources of lycopene include tomatoes, guava, apricots, watermelon, papaya, red bell peppers, and pink grapefruit.

Selenium

People who live in areas of the world where food is low in selenium are at a greater risk of developing asthma. One study showed that two to five times more people who have low selenium levels developed asthma than people who have higher levels.

When people with asthma were given selenium, their symptoms improved greatly. Selenium is an important part of the antioxidant system of the body. When antioxidants like vitamin E neutralize free radicals, they become inactive. Selenium helps reactivate these antioxidants so they can continue doing their job of protecting the body.

Excellent sources of selenium include crimini mushrooms, cod, shrimp, salmon, snapper, yellowfin tuna, halibut, and calf's liver.

Nutrient Excesses

Substances to Avoid

Omega-6 Fatty Acids

Vegetable oil is good for you, right? Well, in the case of heart disease, yes, vegetable oils are better than artery-clogging saturated fats like lard. But in the case of asthma, many vegetable oils can actually do more harm than good.

Vegetable oils can be high in omega-6 fatty acids. While a certain amount of these are needed, too much can be a problem. When cells have a lot of omega-6 fatty acids on hand, they tend to produce substances, like prostaglandins, that increase inflammation in the body.

In addition, when these fats come into contact with free radicals, they can act like very powerful free radicals themselves. All of this can add to the symptoms and attacks of asthma patients. Simply replacing these types of refined vegetable oils, like corn oil and safflower oil with other types of fats, like olive oil or the omega-3 fats found in fish, can have a big impact on asthma.

Salt

You probably already know that too much salt can raise blood pressure. Did you also know that salt can make asthma worse? Studies have shown that high intakes of table salt can make air passages more hyper-reactive to chemicals and pollutants.

Areas where more table salt is used tend to have higher rates of asthma than areas where less salt is used. The connection between salt use and lung reactivity seems to be more important for men and boys, though researchers are not sure why. Replacing salt in meals with more flavorful spices, such as garlic, rosemary, dill, cumin, and basil may eventually lead to improvements in asthma symptoms as well as more interesting tasting food.

Artificial Food Additives

How carefully do you read food labels? Artificial food additives, like colorings and preservatives, are strong asthma triggers for many people. Tartrazine, or yellow dye #5, can be a huge source of problems for asthma sufferers, especially ones who also react badly to aspirin.

Unfortunately, tartrazine is found in many processed foods including canned vegetables, chewing gum, soft drinks, hot dogs, some pastas, butter, some breads, cheeses, fruit juices or drinks, ice cream, jellies, pickles and relish, sherbert, catsup, and even some prescription or over-the-counter medications.

People who react to tartrazine must read food labels very carefully or else they can wind up with an asthma attack.

Other additives that people tend to react to include MSG (monosodium glutamate), which is used to flavor many processed foods and especially in Chinese restaurants, and sulfites, which are used as preservatives in many packaged foods and alcoholic beverages, and which are also often sprayed on salad bar foods to keep them looking fresh.

People who have problems with these and other chemical additives must be very careful to avoid them. Fortunately, organic, healthy foods donít contain artificial dyes or preservatives and are therefore much safer to eat.

Adverse Food Reactions

Have you ever kept track of what happens to you after you eat certain foods? Adverse food reactions may also contribute to the symptoms of many asthma sufferers. Most asthma patients know of at least one food that makes their symptoms worse or triggers their asthma attacks.

The most commonly cited food, especially for children, is milk and other dairy products, followed by eggs. However, adverse food reactions vary greatly depending on the individual. A food and symptom diary or an allergy elimination diet may be helpful for identifying food triggers. Removing these foods from the diet may help reduce symptoms.

Recommended Diet

Imagine a fresh, organic mixed greens salad with pure, extra-virgin olive oil and balsamic vinegar dressing followed by a juicy, pink salmon steak baked with fresh rosemary and served on a plate of brightly-colored steamed vegetables followed by a big bowl of sweet, ripe fruit. This is one example of a healthy, delicious meal for people with asthma.

The diet of an asthma sufferer should be one that includes generous amounts of vegetables. Lightly steaming vegetables helps bring out their flavor, as well as making them easier to digest.

Fruits can be even more sweet and satisfying than sugary desserts, and they're much better for you as well, packed with powerful antioxidant nutrients to protect against the harmful effects of pollution.

Forget the burgers and add a few servings of baked or poached cold water or oily fish to your diet every week. These include fish like salmon, cod, halibut, mackerel, tuna, sardines, and herring.

Instead of smothering your fresh salad with heavy refined vegetable oils like corn or safflower oil, try some pure extra-virgin olive oil. Instead of coating a piece of fresh-baked bread with salty margarine, try using an olive oil vinaigrette as a light dipping sauce.

Put the salt shaker in the pantry and get out the spices to give your meals more flavor and zip. Youíll wind up making them healthier in the process.

Switching your diet from one high in refined foods loaded with salt and artificial preservatives and additives to one high in nutrient-rich, fresh, organic produce, cold water or oily fish, pure olive oil, and zesty spices may go a long way towards helping restore the normal function of the lungs and keeping air passages open.

The Condition Specific Meal Planner for Asthma has menus that cover the nutritional needs of this condition over a four day period.

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This page was updated on: 2004-11-21 13:43:41
© 2002 The George Mateljan Foundation