Smoking is a Risk for a Lot More Diseases Than We Thought

There has been a lot of news/noise lately about smoking and nicotine. From the Biden administration proposing a lower cap on nicotine levels in cigarettes, to the FDA battle with the vaping company Juul. It might make you wonder: Why the renewed interest? Humans have had a long history with tobacco and nicotine products. We know the risks. We want people. Why is this an ongoing battle?

One reason is that we have not actually had a full picture of all the risks. Increasingly old data that had been unavailable is coming to light and new data is being presented and evaluated that paint a much bigger picture of the personal and societal health impacts of cigarettes, tobacco, and nicotine products.

A new analysis published in the Lancet journal eBioMedicine1 gives some insight into how just broad-reaching the lifetime toll of tobacco consumption might be – well beyond lung and cardiovascular risks that are well-established. The authors utilized de novo Mendelian randomization (MR) analyses “using summary statistics data from genome-wide association studies” to assess the impact of smoking and smoking behavior on circulatory, digestive, nervous system, musculoskeletal, endocrine, metabolic, and eye health, as well as on cancer risk. The CD offers a good explanation of MR analysis here2, and why it is a valuable tool for public health. Essentially, this kind of analysis assess the genetic liability of a modifiable disease risk. This kind of study minimizes the bias that can be criticized in observational studies as genetic data is not related to other influences.

To summarize, on the negative side, smoking was associated with:

  • 13 circulatory system diseases
  • Diverticulitis, gallstones, gastroesophageal reflux, Crohn's disease, and acute pancreatitis
  • Periodontal disease
  • Epilepsy
  • Risk of fracture, osteoarthritis, and rheumatoid arthritis
  • Polycystic ovary syndrome
  • Type 2 diabetes
  • Age-related macular degeneration and cataracts
  • Cancers of the lung, head and neck, esophagus, pancreas, bladder, kidney, cervix, and ovaries, and myeloid leukemia

On the plus side, smoking was associated with a decreased risk for:

  • Parkinson’s Disease
  • Prostate Cancer

Leaving aside the matter of autonomy and personal choice, having a full picture of the human cost of consumer tobacco and nicotine use should be helpful in understating how these products are regulated, sold, and used. These data provide us with a bigger picture of the global impact of these products that helps to validate some observational studies, and perhaps points to areas that should be observed more closely.

 

References

  1. Larsson SC, Burgess S. Appraising the causal role of smoking in multiple diseases: A systematic review and meta-analysis of Mendelian randomization studies. eBioMedicine. 2022;82:104154. doi:10.1016/j.ebiom.2022.104154
  2. What is Mendelian Randomization and How Can it be Used as a Tool for Medicine and Public Health? Opportunities and Challenges | CDC. Published April 28, 2022. Accessed July 15, 2022. https://www.cdc.gov/genomics/events/precision_med_pop.htm