The following are drawn from recommendations by WHO, the European Food Safety Authority (EFSA), the European Respiratory Society (ERS), the American Thoracic Society (ATS) and the Société de Pneumologie de Langue Française (SPLF).
Eating foods rich in antioxidants can counter the damage done to the body by oxidative stress, as antioxidants effectively ‘mop up’ free radicals and so prevent them from causing damage. Sources of vitamin C include citrus fruits (oranges, lemons, grapefruit), kiwi fruit, broccoli and green peppers; beta-carotene is present in apricots, mangoes, carrots, peppers and spinach; vitamin E can be found in grains, wheatgerm, almonds and peanuts; lycopene is found in tomatoes and processed tomato products; and grains, Brazil nuts, animal products (especially organ meats) and seafood contain selenium.
Magnesium is the fourth-most abundant mineral in the body and is essential for good health. Magnesium aids the action of the enzymes that facilitate the chemical reactions in the body. Magnesium may also help the airway smooth muscle to relax and help control the body’s response to infection. It is found in nuts, cereals, seeds, carrots, spinach and seafood.
Omega-3 polyunsaturated fatty acids are essential for good health but are deficient in most people’s diets. Omega-6 fatty acids are also essential but are over-consumed. The ideal ratio of omega-6 to omega-3 in the diet is 4 to 1. However, in the average modern diet the ratio is closer to 20 to 1. Omega-3 fatty acids are found in oily fish and shellfish, soy and leafy vegetables.
A balanced diet
A balanced diet with a high intake of fruit, vegetables and fish reduces the risk of developing lung diseases, especially asthma and COPD. Although the effects of diet on the lungs are still under study, it is clear that the following advice can help to maintain good lung health:
- Eat a balanced diet with a lot of fruit, vegetables and fish.
- Reduce salt intake.
- Restrict the amount of trans- and omega-6 fatty acids in the diet.
- Maintain an ideal weight, with a BMI of 21–30 kg·m-2.
- Undertake moderate exercise.