The findings of a new study has linked intake of apples and selenium to reduced risk of asthma. The researchers believe that certain antioxidants present in the apple may prevent lungs diseases. Antioxidants are basically compounds that reduce the effect of harmful ‘free radicals’ (free radicals are substances having a tendency to damage the cells in the body and contribute to chronic disease).
To find the role of antioxidants in asthma, researchers conducted a survey involving 1500 adults and enquired about their dietary habits (especially about the intake of fruits and vegetables, flavonoid-rich foodstuff like apple, onion, tea, antioxidants, vitamins and trace elements which act as antioxidant enzymes such as selenium, zinc and copper).
It was observed that those people who ate at least 2 apples in a week reduced their asthma risk by 22-32%. The researchers also found that as the intake of selenium increased, the asthma risk declined. Those people who were taking a higher intake of selenium (i.e. 54-90 mgm per day) were only half as likely to have asthma as compared to those who took less selenium (i.e. around 23-30 mgm per day). According to the US recommendations daily intake of selenium is 55 mgm.
Researchers believe that decreased risk of asthma linked to apple consumption may be due to the presence of certain subtypes of flavonoids (which is an antioxidant), which have anti-inflammatory and anti-allergic properties. Flavonoids are also believed to inhibit histamine release and cytokine production. A detailed study will be needed to understand the exact effect of these antioxidants on lungs.
Selenium is itself an antioxidant and researchers believe that it may prevent asthma by reducing inflammation in the airways. Selenium also helps to stimulate the immune system. Selenium is found in wheat germ, whole grains, brown rice, barley, brewers yeast, liver, fish, walnuts etc.
Hence, the findings of this study suggest that eating at least two or more apples per week and higher intake of the essential metal selenium can protect against asthma in adults.