Abstract
Background: While the effects of cigarettes on health are well-established in scientific literature, the health effects of marijuana have been less intensely studied. Emerging theories exploring the benefits of marijuana use along with the high use rates in New Zealand, indicate that further research is needed. A known negative health effect of cigarette use is oxidative stress. Oxidative stress is a state of imbalance between antioxidants and reactive oxygen species in the body leading to tissue and cell damage and contributing to ageing and multiple chronic diseases.
Aim: To investigate if smoking cigarettes and/or marijuana have an impact on systemic markers of oxidative stress. Specifically, to measure biomarkers of protein and lipid oxidation in the plasma and urine of smokers and non-smokers.
Methods: The research used urine and blood samples collected from 70 participants (50 non-smokers and 20 smokers) in the Christchurch Health and Development Study cohort at their most recent data collection. Samples were analysed by the student researcher using ELISA. protein oxidation was determined by measuring protein carbonyls in the plasma and lipid oxidation were determined by measuring F2- isoprostanes in the urine. The urine samples also underwent toxicology screening by Canterbury Health Laboratories to determine cannabinoid and cotinine concentrations.
Results: The results showed that there was significantly higher lipid oxidation markers in those who smoked cigarettes and/or marijuana (n=20) in the last 30 days compared with those who did not (n=50, p=0.004). However, there was no significance between the two groups for the protein oxidation markers (p=0.95). There were also significantly higher lipid oxidation markers in those who had smoked marijuana and cigarettes in their lifetime (n=30) compared with those who had only smoked cigarettes (n=28, p=0.02). The effect of smoking cigarettes or marijuana on lipid oxidation did not appear to be dose-dependent although the participant numbers in these subgroups were small.
Conclusions: Lipid oxidation markers were elevated in those who had smoked cigarettes and/or marijuana in the last 30 days and in those who had consumed both marijuana and cigarettes in their lifetime. Health professionals should appropriately assess patients' smoking habits whether that be of cigarettes and/or marijuana, and take the appropriate steps to manage those at high risk of oxidative stress such as encouraging smoking cessation, vitamin supplementation and antioxidant rich diets.