Posted by Chantel Martiromo
Respiratory Disease is defined as medical conditions which affect the breathing organ and tissues including Inflammatory lung disease, Obstructive lung diseases, Restrictive lung diseases, Respiratory tract infections, trachea, bronchi, bronchioles, alveoli, the nerves and muscles breathing , etc.
Asthma is a chronic inflammatory disease affecting the air way of the lung with recurring symptoms, such as wheezing, chest tightness, shortness of breath, and coughing. The disease affects people of all ages, and mostly starts during childhood. According to American academy, allergy, asthma and immunology, about 1 in 10 children (10%) had asthma and 1 in 12 adults (8%) had asthma in 2009. (about 25 million, or 8% of the U.S. population).
Epidemiological studies linking vitamin A in reduced risk and treatment of asthma have been inconclusive(a)(b)(c)(d)(e), but according to the University G. D'Annunzio, and Respiratory Pathophysiology Center, dietary supplementation or adequate intake of lycopene and vitamin A rich foods may be beneficial in asthmatic subjects(f).
1. Retinols
Serum vitamin A concentrations was found significantly lower in asthmatic subjects than healthy control subjects and administration of all-trans retinoic acid, ATRA dramatically attenuated airway inflammation through inhibiting Th2 and Th17 differentiation and/or functions. according to the Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine(1). ORMDL3 is a candidate gene of childhood onset asthma, and high-transcript of ORMDL3 is associated with the development of asthma. According to Nanjing Medical University, all-trans retinoic acid (ATRA) is an active metabolite of Vitamin A, reduced the risk of asthma through maintained airway epithelial integrity, inhibited asthma effector cells differentiation, modulating immune response, possibly via facilitates ORMDL3 production probable through PKA/CREB(2). Also in all-trans retinoic acid, ATRA, the Tehran University of Medical Sciences study suggested that ATRA diverted the human immune response in neutral conditions (without adding polarizing cytokines) by increasing FOXP3+ cells and decreasing RORγt+ cells(3). In rats with asthma, ATRA was found to alleviate airway hyperresponsiveness and airway remodeling possibly through decreasing the protein expression of MMP-9(4). The study at 1Inserm U700 and Université Paris 7, in a mouse model of ovalbumin (OVA)-induced T helper (Th) 2-type responses and airway remodeling, indicated a effectiveness of liposomally encapsulated ATRA (Lipo-ATRA) in exacerbates allergic immune and inflammatory responses, most likely through promoting Th2 development(5).
Unfortunately, according to Johns Hopkins University, even though animal models suggest that vitamin A deficiency affects lung development adversely and promotes airway hyperresponsiveness, and may predispose to an increased risk of asthma, but vitamin A supplementation early in life was not associated with a decreased risk of asthma in an area with chronic vitamin A deficiency(6).
2. Carotenoids (beta-carotene, alpha-carotene, gamma-carotene and beta-cryptoxanthin) Carotenoids, plant pigments, converted to vitamin A after intake, play an important role in prevention and treatment of some diseases through it antioxidant effects. In the study of the effect of vitamin intake among asthmatic subject, researchers at the Hung Kuang University, found that nutritional supplement therapy including beta carotene may improve dysregulated oxidant and antioxidant status, inflammation and immune responses, pulmonary function, and health-related quality of life in patients with mild to moderate allergic asthma(7). The John Hunter Hospital study of asthmatic subjects with airway hyper-responsiveness (AHR), indicated a reduced levels of beta-carotene and alpha-tocopherol compared with those without AHR, possibly due to impaired antioxidant defences and are thus most susceptible to the damaging effects of oxidative (8). Other researchers suggested that the imbalance of antioxidants found in asthmatic patients may be the possible causes of the disease(9) and modifying the dietary intake of carotenoids alters clinical asthma outcomes with improvements evident only through increased whole foods intake, not supplements(10)
But according to the study of Yamaguchi University, there was no significant association for asthma in Japanese youth(11) and the study of a total of 423 children from a rural area of Thailand, in a Health Interview for Asthma Control questionnaire, showed no correlation of dietary intake of carotenoids between asthmatic and non-asthmatic children(12).
Taken altogether, using vitamin A in prevention and treatment of asthmatic patient remains controversial. According to the study in summarized the important of vitamin A in treatment of asthma, excessive intake of vitamin A may increase the risk or severity of asthma in industrialized countries whereas vitamin A deficiency continues to increase mortality from infectious diseases in developing countries(12)(13). Overdoses can lead to toxic symptoms. Please make sure you follow the guideline of the Institute of Medicine of the National Academies.