Chinese herbal medicine has become increasingly popular around the world for the promotion of health and adjuvant therapy [18–20]. To our knowledge, this prospective clinical research was the first study to assess the effects of Lung Support Formula, the nutritional supplement containing natural Chinese herbs, on the improvement of respiratory symptoms in older adults. The findings from this study suggested that Lung Support Formula might be beneficial to older adults by improving respiratory symptoms. The treatment was well-tolerated and none of the observed adverse events were considered drug related. There were obvious improvements in the respiratory symptoms in the treatment group; the total scores show a decreasing tendency with progress of drug taking, and the severity of symptoms presented a tendency to be gradually relieved. Based on the concrete symptoms, Lung Support Formula is useful for improving chronic cough, chronic expectoration and chronic bronchitis or bronchitis, but the efficacy of improving asthma, dyspnea and chronic angina is not obvious. Placebo effect was found in the control group; the total scores of respiratory symptoms decreased significantly after the first follow-up, but remained stable in the subsequent follow-up. This suggested that the placebo effect played a role in the subjective effect of the symptom scores and the change of scores were significant, but the placebo effect kept the symptom scores stable as treatment progressed. The scores of the treatment group improved gradually with supplement administration at the same period.
Lung Support Formula contains natural ingredients with multiple pharmacological properties, including Astragalus membranaceus, Cordyceps sinensis, Ophiopogon japonicus, Panax ginseng, Morus alba and Ginkgo biloba, plus vitamin A , vitamin C, magnesium and zinc which may provide greater clinical effectiveness with fewer side effects than compound-based drugs . As the main pharmacological property of the Lung Support Formula capsules Astragalus membranaceus is used in Traditional Chinese Medicine and has been asserted to be a tonic that can improve lung functions, promote healing, and reduce fatigue . Astragalus membranaceus has antibacterial and anti-inflammatory properties. In addition, a study has shown that astragalus has antiviral properties and stimulates the immune system, suggesting that it may help prevent colds and treat respiratory infections . Cordyceps sinensis is another primary ingredient, which is a potentially ergogenic herb that has been used in Chinese folk medicine for centuries, primarily as a “lung invigorator” . Studies have identified potential performance-enhancing benefits of cordyceps, including increased ventilation capacity  and improved glucose metabolism . Ophiopogon japonicus is an important traditional Chinese herbal medicine and has many health benefits in treating a wide range of disorders . Herbalists use ophiopogon to treat certain respiratory conditions because it is known to stimulate production of mucus, making coughs more productive. As we know, minor infections, especially infections like viral bronchitis, which cannot be treated with antibiotics, can be more easily cleared out of the respiratory tract if a patient has a productive cough. Current research also finds that saponin from ophiopogon can be explored as a novel and potential natural immunostimulant that may have several kinds of bioactivities, such as antiviral, anti-inflammatory, antiparasitic, immune-enhancing, anticancer, and antimicrobial activities . Panax ginseng is a popular herbal remedy that has been used for thousands of years. It has been an important part of the pharmacopoeia of Traditional Chinese Medicine and is classified as an adaptogen that is thought to increase the body’s overall resistance to stress and infection . A research study demonstrated that ginsenoside, an essential constituent of Chinese anti-asthmatic herbal medicine and aphrodisiacs, relaxes human bronchial smooth muscle presumably through a stimulation of nitric oxide generation by airway epithelium . These 4 primary ingredients of Lung Support Formula are all beneficial to reduce respiratory symptoms.
Among the strengths of our research was the fact that it was a clinical study with a 3-month follow-up, allowing for more precise estimation of effects. However, the present study had several limitations. First, the sample size of our research was relatively small and the duration of study was not long enough; larger multicentre and longer-term treatment studies are warranted to verify the effects of Lung Support Formula. Second, one of the primary outcome measures was the respiratory symptom scores developed by a 5-point Likert scale, which was based on self-reporting by patients, who might underreport or overreport their symptoms. This bias cannot be determined from the data without objective measurements as in other studies [4, 30, 31], however, reliability study (Cronbach’s Alpha coefficient) had indicated good fitness results for the evaluation of respiratory symptom scores in our research.
Despite these limitations, the current study provides evidence of the improvement of respiratory symptoms among older adults by taking Lung Support Formula. Findings also indicate this natural product with multiple pharmacological properties is safe.