Nicotine exposure studied in mice

Researchers from the University of California at Santa Cruz studied how nicotine affects the immune system in offspring of pregnant mice, publishing their findings in Stem Cell Reports. They exposed pregnant mice to nicotine through their drinking water during pregnancy and the early stages of their offspring's lives to isolate nicotine's effects from other chemicals in tobacco or e-cigarette vapor.

Immune system changes observed

The study found that nicotine exposure during the perinatal period—covering pregnancy and early life—could permanently alter certain parts of the immune system. The development of specific immune cells, which are vital for defending the body against infections, was disrupted during this critical time.

Long-lasting effects on lung defenses

These changes in immune function persisted into adulthood, with the lungs being particularly affected. Mice exposed to nicotine had fewer cells responsible for protecting the lungs from external threats, such as viruses or pollutants.

Immune system not fully weakened

Despite these changes, the overall immune system was not entirely compromised. Many large categories of blood cells in nicotine-exposed mice were similar to those in mice not exposed to nicotine. The effects seemed to target specific types of immune defenses rather than the entire system.

Nicotine exposure linked to worse infection outcomes

To test the long-term consequences, researchers infected adult mice with the influenza virus. Those previously exposed to nicotine lost more weight, had more severe lung damage, and showed a more intense and imbalanced immune response compared to mice not exposed to nicotine.