Asthma is a widespread chronic respiratory disease, affecting approximately one out of 12 individuals in the United States in 2009, according to the Centers for Disease Control and Prevention. Symptoms include wheezing and difficulty breathing caused by swelling of the bronchial tubes, which narrows the airway. Diet may have an influence on the inflammation of the airway. Certain kinds of fruit, including those rich in antioxidants such as flavonoids and Vitamin C, may help reduce the airway inflammation that causes asthma.
According to the Al-Quds Nutrition and Health Research Institute, fruits rich in antioxidants, including vitamin C, vitamin E, carotenoids, selenium and flavonoids, may help reduce airway inflammation. These antioxidants may protect the cells in the airway from oxidative damage by neutralizing free radicals. Free radicals can increase inflammation and worsen asthma by causing the airway to tighten and close.
According to a 2007 study by Caroline M. Kamau at Bowling Green State University, the antioxidant flavonoids found in fruits such as apples may help reduce the inflammation associated with asthma. Eating fruits rich in flavonoids may reduce your risk of asthma, decrease your bronchial sensitivity and improve your general pulmonary health. Apples in particular are rich in flavonoids. A strong inverse relationship exists between the amount of apples people eat and the severity of their asthma -- people who eat more apples are less likely to display the symptoms of asthma, according to Kamau's study. Other fruits rich in flavonoids include apricots, grapes, cantaloupes, oranges, peaches and pears.
Large doses of the antioxidant vitamin C may reduce the inflammation behind exercise-induced asthma. A study conducted by Sandra Tecklenburg, et al., published in "Respiratory Medicine" in 2007 revealed that 1,500 mg of vitamin C taken daily for two weeks helped prevent this type of asthma. Blackberries, grapefruit, kiwis, oranges and mangoes are all excellent sources of vitamin C. Vitamin pills containing vitamin C in the form of ascorbic acid are also available for those who are unable to meet these levels through consumption of fruit.
Beta-Carotene and Lycopene
According to the University of Maryland Medical Center, beta-carotene and lycopene may help relieve the symptoms of exercise-induced asthma. Red fruits such as watermelon, tomatoes, and pink grapefruit are good sources of lycopene, which is a natural plant pigment contributing to the color. Beta-carotene is responsible for the orange or yellow color of many fruits, and is found in yellow apples, apricots, grapefruit, cantaloupe, lemons, mangoes and oranges.
According to a 2005 study by Eric Secor published in "Cellular Immunology," bromelain, an enzyme found in pineapples, may reduce the inflammation associated with asthma. However, the study was performed on mice so may not garner the same results in humans. The enzyme bromelain is extracted from the stem and juice of the pineapple plant. Capsules and pills containing bromelain are available for sale. Many people in Europe in particular purchase this enzyme for relief of their asthma symptoms.
Although including fruit in your diet may help reduce the severity of your asthma, dried fruits often contain sulfites which could cause an adverse reaction or worsen your symptoms. Eat fresh fruits and avoid all dried fruits preserved with sulfites.