An asthma attack -- in which one can't get enough air -- can be an extremely frightening experience. So, of course, you'd do anything to avoid one. And it turns out watching your diet may be one such thing.
According to internist Dr. Alan Gaby, an unrecognized food allergy or intolerance is a contributing factor in at least 75 percent of childhood asthma cases and about 40 percent of adult cases.
"As early as 1959, Dr. Albert H. Rowe, a pioneer in the field of food allergy, successfully treated 95 asthmatic patients with dietary changes alone," says Gaby.
Asthma is a chronic disease that affects the pathways that carry air in and out of the lungs. When a person has asthma, those airways become inflamed and sensitive to a variety of substances (in air, food and the environment). The response is similar to an allergic reaction, which is one reason asthma is often linked to allergies.
The immune system of someone with asthma mistakenly identifies substances, such as pollen, dust, dander and certain foods, as being dangerous. It overreacts to protect against the substance by creating inflammation in your lungs and narrowing your air passages. Muscles around the airways tighten up, allowing less air in; the airways become even more swollen and narrow, and it becomes harder to breathe.
Dairy products top the list of foods most likely to provoke asthma. Other suspects include tree nuts (such as cashews, almonds and walnuts), milk, eggs, soy, chocolate, wheat, corn, citrus fruits and fish. Tartrazine (yellow dye No. 5), which is used in many foods, including cereals and soft drinks, is believed to be a trigger for thousands of people. And, according to the National Heart, Lung and Blood Institute, foods with sulfites -- such as beer, dried foods, processed potatoes, shrimp and wine -- may also trigger asthma symptoms in susceptible people.
Knowing that some foods can make asthma worse, you might wonder if there are foods that can help calm asthma symptoms.
You may not be able to completely wipe out asthma symptoms with food, but emerging evidence points to the fact that higher intakes of omega-3s and vitamin C from food (especially fresh fruit) and supplements can certainly help.
Because asthma is an inflammatory condition, to fight that response make sure your diet contains foods rich in natural anti-inflammatories, such as omega-3's (found in cold-water fish such as salmon, sardines and tuna) is a really good idea. The plant flavonoid quercetin, found in apples and onions, is highly anti-inflammatory, as is the spice turmeric.
"In my experience, increasing the intake of plant-based fat (avocado, extra-virgin olive oil, almonds), fruits, vegetables and whole grains can help considerably", says nutritionist Cynthia Sass. She adds that probiotic and omega-3 supplements may also help.
Another supplement that might be helpful is the oil of the shea nut. Shea nut oil extract with a high tripertene content has been shown in more than 30 clinical studies to be highly anti-inflammatory. It is available in an over-the-counter supplement called FlexNow.
Low intakes of vitamin C from food or supplementation can lead to increased risks for asthma. A 2005 study done by researchers from the Asthma and Allergy Research Institute in Australia found that the blood concentrations of vitamin C were markedly lower in patients with severe asthma. A review article in the American Journal of Clinical Nutrition concluded that "symptoms of ongoing asthma in adults appear to be increased by exposure to environmental oxidants and decreased vitamin C supplementation."
Studies have shown that one to two grams of vitamin C per day is most helpful. This level is also helpful for those suffering from allergies. Foods high in vitamin C include peppers (green and red), kale, leeks, broccoli, cauliflower, Brussels sprouts, guavas, oranges, grapefruit, kiwis, peaches, oranges, strawberries and pineapples. Although it's best to get your vitamins from food, you may need to include supplements in your diet to get adequate amounts.
Following a Mediterranean diet has been shown to improve asthma control, possibly because of the high content of omega-3's and vitamin C. This diet is full of fresh fruits and vegetables. The ones mentioned above can help you get your requisite C, and omega-3s are plentiful in the olive oil, nuts, avocado and fatty fish, such as salmon and sardines, which the diet features. A 2008 study in the journal Allergy found that high adherence to a Mediterranean diet reduced the risk of noncontrolled asthma by a whopping 78 percent. Those people who were controlling their asthma had significantly higher intakes of fresh fruit in their diet.
And, since these foods are so good for you anyway, they certainly couldn't hurt.