Cannabis use has been controversial, largely having been designated a controlled substance over the past century. While certain studies have linked cannabis smoking with harmful effects such as increased respiratory symptoms and faster lung function decline in older adults [1, 2], these findings have not been fully replicated by others [3]. The link between cannabis and disease pathogenesis may best be explored through DNA methylation. This mechanism consists of the addition or removal of a methyl group at a cytosine–guanine residue (CpG), can be influenced by exposures, and can modify transcription. Methylation changes can accumulate over time in patterns that are highly associated with age, leading to the development of epigenetic clocks that can estimate biological age [4].

大麻的使用一直存在争议，在过去的一个世纪中很大程度上被指定为受控物质。虽然某些研究将吸食大麻与老年人的呼吸道症状增加和肺功能衰退加快等有害影响联系起来 [1, 2]，但其他研究尚未完全重复这些研究结果 [3]。大麻与疾病发病机制之间的联系最好通过 DNA 甲基化来探索。该机制包括在胞嘧啶-鸟嘌呤残基 (CpG) 处添加或去除甲基，可能会受到暴露的影响，并且可能会改变转录。甲基化变化可以随着时间的推移以与年龄高度相关的模式累积，从而导致可以估计生物年龄的表观遗传时钟的发展[4]。