Glutathione (GSH) is an antioxidant. All of your cells and majority of your major organs produce them. It has many functions including your master antioxidant, enhancement of your immune system, and your primary detoxification pathway.
In other words, it’s your 1st line of defense against environment toxins and pollution.
The epithelial lining fluid (ELF) in the lungs has 140-fold more glutathione than in the plasma. Smokers, on the other hand, have 80% more.
So what’s the relationship between glutathione, smoking, and cancer?
Cigarette smoking (CS) exposures evoke a powerful GSH adaptive response in the lung and systemically. These data suggests that there may be a sensor that sets the ELF GSH adaptive response to prevent GSH levels from dipping below basal levels. Likewise, factors that disrupt GSH adaptive responses may contribute to the pathophysiology of chronic obstructive pulmonary disease (COPD)
Epidemiological evidence indicates that most human cancers are caused by environmental exposure to genotoxic agents. It is estimated that as many as two thirds of all human cancers originate from exposure to tobacco smoke and dietary components . Tobacco use is a well-known risk factor for multiple types of cancer. This includes lung, esophagus, and bladder cancers. It was estimated that there would be well over 150,000 deaths due to lung cancer in United States in 1995 . Therefore, it’s important to prevent lung cancer by reducing exposure to tobacco and possibly intervening in the carcinogenic process at an early stage. Despite the risks, most smokers do not develop lung cancer. Granted, the lifetime risk of lung cancer in subjects smoking 20 cigarettes per day is still under 15 % . This suggests that there may be important endogenous and exogenous factors that are likely to affect an individual’s lung cancer risk.
GSTMI catalyses the conjugation of a wide range of genotoxic and cytotoxic metabolites of tobacco smoke. And because the deficiency in GSTMI increases the susceptibility to DNA-adduct formation  as well as cytogenetic damage , individuals with GSTMI deletion could potentially be at greater risk of developing smoking-related lung cancers.
Summary in Layman’s Terms
Two thirds of cancers originate from tobacco smoke and dietary components. But less than 15% of smokers contract cancer. Most of those individuals lack the gene for glutathione enabling detoxification.
Therefore, changes of AO status parameters and oxidative damage in cell structures are related to tumor processes indicating the augmentation of oxidative stress in human blood. This study demonstrated potential applicability of a statistical model based on the evaluated biomarkers of oxidative stress to determine a smoking induced harm of cancer incidence in healthy subjects.
Summary in Layman’s Terms
Smoking depletes glutathione levels which leads to oxidative stress which is a cause of cancer.
GSH deficiency increases with age. As a result, it causes more inflammation for smokers.
- Correlation between Oxidative Stress, Nutrition, and Cancer Initiation
- Oxidative stress, inflammation, and cancer: How are they linked?
- Ray D. Strand M.D. on Cancer
When you are younger, your lungs have additional glutathione levels to protect you from oxidative stress. Even if you’re a smoker. As you age past 40, however, your ability to produce glutathione declines. The toxicity of smoking and other environmental toxins gradually increases oxidative stress. This ultimately leads to various diseases and conditions including cancer.