Regular readers of our Breathe Better for Life e-letters and Breathe Better Blog are well aware we are strong advocates of antioxidants for people with chronic shortness of breath. Our perspective - we view antioxidants as an excellent addition to a regular exercise program, a Mediterranean-style diet and smoking cessation to reduce inflammation and oxidative stress.
We do not believe that antioxidants will cure, reverse lung disease or improve lung function. However, there is substantial and growing evidence that oxidative stress (an imbalance in damaging pro-oxidant molecules known as free radicals and protective anti-oxidant molecules) is a key contributing factor to the sensation of breathlessness and that most COPD patients are significantly deficient in antioxidants compared to those without persistent shortness of breath.
We are not alone in this belief as a new research paper echoes many of our sentiments. This research review article, published in the journal Current Drug Targets, examines the role of oxidative stress in COPD and the potential of antioxidants as a supportive therapy. In fairness to the review authors, they acknowledge that while antioxidant therapy seems a key area for further exploration there are conflicting study results on the effectiveness of antioxidants for COPD patients. Further, they acknowledge there are few definitive guidelines regarding the optimum human daily dosages for the most promising antioxidants. 
Still we’re concerned that it will be decades before enough researchers and practitioners determine these criteria to their own satisfaction. Meanwhile, millions of COPD patients will not learn of the potential benefits that have already been reported in peer reviewed published research for over the past decade.
So, we thought it would be helpful to share some snippets of this research review paper so that readers have access to the emerging potential of antioxidants as a supporting therapy to other traditional COPD treatments.
First, some observations about oxidative stress and COPD offered in the paper’s introduction, “The lung is the organ with the highest exposure to ambient air in the entire human architecture. Due to its large surface area and blood supply, the lung is susceptible to oxidative injury in the form of myriads of reactive oxygen species (ROS) and free radicals. ROS may be produced endogenously by metabolic reactions or have exogenous origins, such as air pollutants or cigarette smoke. Airborne pollutants may result in direct lung damage as well as in activation of inflammatory responses in the lungs. Tobacco smoke is a mixture of over 4700 chemical compounds, including high concentrations of oxidants. Inflammatory cells recruited in airspaces become activated and generate ROS in response to appropriate stimuli.”
“Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory disease which is characterized by an abnormal inflammatory response of the lungs to external stimuli, the most common being tobacco smoke. This abnormal inflammatory response is attributed to many underlying pathophysiologic mechanisms and one of the most important is the imbalance of oxidative stress and antioxidant defenses.”
For a layman’s understanding of the above process, we recommend readers check out our War of the Worlds in Your Lungs article.
Regarding antioxidants, the review authors explain, “In order to provide defense against the oxidative burden, the lungs produce various endogenous agents called antioxidants. The antioxidant species help the lungs ward off the deleterious consequences of a wide variety of oxidants/reactive oxygen species and reactive nitrogen species, either of endogenous or environmental origin. The major nonenzymatic antioxidants of the lungs are glutathione, vitamins C and E, beta-carotene, uric acid, whereas the major enzymatic antioxidants are superoxide dismutases, catalases and peroxidases. These antioxidants are the first lines of defense against oxidants and usually act at a gross level.”
As a side note, the most powerful of these antioxidants is glutathione. That said the human body does not absorb glutathione well when administered directly. Our bodies are much better at producing our own glutathione when we are provided precursors of the antioxidant. The most effective precursor in assisting the body’s production of glutathione is N-Acetyl Cysteine (NAC).
“Oxidative stress is intimately associated with the progression and the development of exacerbations in COPD. A rational approach for the treatment of COPD would therefore be to consider antioxidant intervention not only aiming to neutralize the increased oxidative stress and the subsequent inflammatory response, but also in an attempt to identify the source of oxidants and overwhelm their generation. This can be achieved through two approaches, either by increasing the endogenous antioxidant enzyme defences or by enhancing the non-enzymatic defences through dietary or pharmacological means. To date, however, most clinical trials of antioxidants for COPD have yielded conflicting or disappointing results.”
Despite these conflicting and disappointing results, however, the study authors conclude, “There is now solid evidence for the role of oxidative stress in the development and evolution of COPD. Several biomarkers of oxidative stress have been evaluated by invasive and non-invasive means in patients with COPD. However, further standardization of methods is imperative for the application of such biomarkers in clinical practice. An effective wide-spectrum antioxidant therapy with bioavailability is urgently needed to control the local and systemic oxidative burst in COPD. In that direction, several antioxidant agents have been evaluated as potential candidates for the management of COPD. However, despite some encouraging results, clinical trials so far have failed to elaborately define the type of antioxidant, the regimen and the time period of treatment that may improve clinically meaningful outcomes in patients with COPD. This may be largely due to the incomplete understanding of the pathophysiology of COPD and the differences within COPD phenotypes. Moreover, some of the antioxidants may not reach the correct cellular/tissue compartment where the oxidative damage is taking place. Well-designed clinical trials investigating the potential role of new antioxidants and combinations of antioxidants with existing anti-inflammatory agents may provide new insights in COPD management."
So the takeaway – not enough evidence yet to satisfy researchers and practitioners regarding efficacy and not enough clear guidance on dosages, but clearly an area that will receive great attention in the future due to the unambiguous connection between shortness of breath, inflammation and oxidative stress.
By the way, the antioxidants with most encouraging study results highlighted by the authors:
• N-Acetyl Cysteine
• Vitamin C
• Vitamin E
• Beta Carotene
Attentive readers will note the above mentioned antioxidants, with the exception of Beta Carotene, are key ingredients of our Resplenish anti-oxidant respiratory support dietary supplement. We’ve further bolstered the formula with other antioxidants that have recently demonstrated promising results in respiratory health studies (including Vitamin D, Quercetin, Coenzyme Q10 and Baicalin). If you are interested to learn more about Resplenish, click here.
Whether our Resplenish supplement is of interest to you or not, we recommend you consider bolstering your daily diet with an antioxidant rich dietary supplement and antioxidant rich foods. While it’s true there is no “gold-standard” when it comes to antioxidant dosages for respiratory health it is also true and undeniable that the primary weapons at the disposal of physicians to combat oxidative stress are the natural agents our bodies already use and/or produce – antioxidants.
 Loukides S, et al. Oxidative Stress in Patients with COPD. Current Drug Targets. 2011; 12: 469-477.