Vanillin, a common flavoring used in e-cigarette liquids, may disrupt the normal development of human embryonic cells, according to a laboratory study by scientists at the University of California, Riverside.
The study’s authors say the findings may also help explain a possible link between vaping and infertility and miscarriage. However, they emphasize that the results do not establish that vaping or vanillin causes these outcomes in humans.
Effects on embryonic stem cells
The scientists conducted a series of laboratory experiments using human embryonic stem cells, which share characteristics with cells found in 3-week-old human embryos.
The researchers exposed the cells to nanomolar, or low, concentrations of vanillin and micromolar, or high, concentrations. They found that micromolar concentrations typically killed the cells, while nanomolar concentrations caused them to lose pluripotency — the ability to develop into virtually any cell type.
Vanillin also promoted the differentiation of stem cells into endoderm rather than ectoderm or mesoderm. Endoderm is the embryonic tissue that eventually forms the lining of the digestive and respiratory tracts.
The scientists said these changes could potentially interfere with normal embryonic development.
Other e-cigarette flavorings
The researchers also examined menthol, a common e-cigarette flavoring, and found that it may contribute to processes associated with respiratory disease. They are now studying WS-23, a synthetic cooling agent frequently used in e-cigarettes, as well as the effects of menthol and WS-23 on embryonic cell differentiation.
Read also: The new smoke-free world: How nations are kicking the habit.
The researchers emphasize that their findings come from laboratory experiments and cannot establish whether the same effects occur in pregnant women or their embryos. The concentrations used in the experiments also do not necessarily correspond to levels of vanillin exposure from vaping.
Further research, including studies that better reflect real-world human exposure, is needed to determine whether vanillin in e-cigarettes poses a risk to embryonic development.
