Introduction
Diet and nutrition are now more widely acknowledged as modifiable factors in the onset and progression of chronic diseases. Numerous studies have shown the significance of nutrition in the early stages of the development of obstructive lung diseases such as asthma and chronic obstructive pulmonary disease (COPD). These respiratory diseases are characterized by severe morbidity and mortality, systemic and airway inflammation, airflow obstruction, deficiencies in lung function, high economic consequences, and severe morbidity and death. Despite expanding therapeutic alternatives, the mainstay of treatment for respiratory problems continues to be pharmaceutical therapy.
Modifying one's diet, however, may be a vital component of disease prevention and a key adjunct to disease care. To clarify their significance in respiratory disorders, dietary patterns and intake of specific nutrients have been assessed in observational and experimental research across life and disease stages. This article discusses more about the link between nutrition and respiratory health.
What Is the Link Between Nutrition and Respiratory Diseases?
Numerous dietary habits have been connected to an increased risk of respiratory diseases.
Epidemiological studies have shown that the Mediterranean diet protects against allergic respiratory diseases. This eating style includes a high intake of plant foods that have had minimum processing, such as fruit, vegetables, bread, cereals, beans, nuts, and seeds; a low to moderate intake of dairy products; an average intake of fish, chicken, and wine; and a low intake of red meat.
High consumption of olive oil lead to a diet that is moderate in terms of total fat but low in saturated fat. A study indicated that a high Mediterranean diet score during pregnancy was protective against persistent wheeze and atopic wheeze in children at 6.5 years of age, suggesting that the Mediterranean diet may also be significant for the maternal diet.
Whereas high consumption of refined grains, cured and red meats, desserts and sweets, french fries, and high-fat dairy products define the "Western" dietary pattern, which is common in developed nations. A higher risk of childhood asthma has been linked to this dietary pattern.
Furthermore, increasing fast food consumption, such as hamburgers, and related eating habits, such as consuming salty snacks often and ordering takeout, are linked to asthma, wheezing, and airway hyperresponsiveness in children. There is evidence to support the claims that a "Western" dietary pattern raises the risk of childhood asthma, is associated with poorer asthma outcomes in adults, and increases the risk of COPD.
The nations with the highest fat intake also have higher lung cancer rates. Moreover, positive relationships between the consumption of total fat and saturated fat and lung cancer have been found in various case-control studies, especially among non-smokers. A high intake of dietary antioxidants such as vitamins A, C, and E, as well as several minerals, is associated with a lower risk of developing major obstructive pulmonary diseases and asthma, according to most research on these factors.
Therefore, adopting dietary supplements has two main benefits: 1) to improve cellular function associated with nutrient deficiencies; and 2) to meet a formal requirement associated with a genetic predisposition or particular circumstances, such as people exposed to oxidants or with persistent infection.
What Protective Role Do Nutrients Play in Respiratory Rehabilitation?
1. Antioxidants
Antioxidants in the lung provide the first line of protection against oxygen-free radicals. These include non-enzymatic antioxidants and endogenous enzyme systems. Because they can be found in the diet, non-enzymatic antioxidants like vitamin C (ascorbic acid), vitamin E (alpha-tocopherol), beta-carotene (a precursor to vitamin A), ubiquinone, flavonoids, and selenium may aid in the host's defense against oxidative lung damage.
a. Vitamin C- A daily intake of 90 mg of vitamin C is advised for men and women. High doses may cause nausea, and diarrhea may occur. A water-soluble antioxidant scavenges oxygen. It restores depleted vitamin E present in lymphocytes and neutrophils. Fruits like strawberries, papaya, cantaloupe, and citrus fruits, as well as vegetables like sweet peppers, kale, cauliflower, broccoli, and Brussels sprouts, all contain vitamin C.
b. Vitamin E- A lipid-soluble vitamin, by stopping the chain reaction of lipid peroxidation, serves as the main line of defense against oxidant-induced membrane damage in human tissue. Adults can handle 200–400 mg/d without experiencing any adverse side effects, except for gastrointestinal distress; 800-1200 mg/d may cause bleeding and an antiplatelet effect; more than 1200 mg/d may cause negative side effects such nausea, headaches, lethargy, and diarrhea. Vitamin E is found in vegetable and seed oils (soybean, corn, and safflower) and eggs.
c. Flavonoids and Carotenoids- Superoxide anions and peroxyl radicals are scavengers in flavonoids like quercetin. A crucial trace element, selenium aids in the detoxification of free radicals and peroxides. Carotenoids and vitamin C are abundant in fresh fruit and vegetables. The primary provitamin A carotenoids, beta- and gamma-carotene, and cryptoxanthin, can be converted to vitamin A. The primary sources of flavonoids include tea, fruit, and vegetables.
2. Minerals
Some minerals, including salt and magnesium, have also been linked to the emergence of airway disorders through their impact on the smooth muscle cells lining the airways. Magnesium has been demonstrated to stabilize mast cells and T lymphocytes, expand asthmatic airways in vivo, block cholinergic neuromuscular transmission, and increase the production of prostacyclin and nitric oxide. A diet high in salt and low in magnesium may increase the chance of developing airway diseases. Lima beans, brown rice, corn, peas, carrots, parsley, spinach, almonds, legumes, cereal, grains, and shellfish all contain magnesium.
3. Omega-3 Fatty Acids
Polyunsaturated fatty acids, which are found mainly in seafood-rich diets, may contribute to lung diseases and the lungs' natural aging process. By altering the composition of lipid membranes and other substrates, which are the substrates for forming eicosanoids, increased consumption of omega-3 fatty acids (FA) can lessen inflammatory reactions. Omega-3 fatty acids are found in fish oils, shellfish, canola, soy oil, and veggies with leaves.
Conclusion
Pulmonologists must include nutritional counseling and dietary evaluation in their routine practice, especially with high-risk patients who already have conditions like tuberculosis, COPD, or asthma. It should be advised to consume more fresh fruit and vegetables. Besides defending against the additional oxidative stress challenge brought on by high levels of air pollution or in subjects with impaired immune response, nutritional supplementation has been shown to benefit lung health. Additionally, suboptimal vitamin status is linked to several chronic diseases. Doctors must recognize patients with inadequate nutrition or other conditions that require higher vitamins. If intake is insufficient to meet demands, supplementation with vitamins C and E may be suggested for high-risk patients.
