Study Identifies Why Passive Smoking Promotes Tumor Growth

Passive smoking accounts for an estimated 600,000 deaths per year worldwide, according to the World Health Organization (WHO). In a new study published by Science Reports, investigators found that the organic compound found in cigarette smoke promotes tumor growth.

While smoking a cigarette, the toxin acrolein (acrylic aldehyde) is released into the atmosphere via sidestream smoke.

“Anyone who has ever sat in a smoky pub has breathed it in—–but what worries us more is long-term profession exposure in smoking establishments, as well as the exposure of children and family members in the home of smokers or in the car, where domestic pets are frequently also exposed,” said lead investigator Erika Jensen-Jarolim and lead author Franziska Roth-Walter.

In addition to smoking, acrolein is also produced when vegetable or animal fats are overheated, by burning of printer inks, and from biodiesel or wax.

The results of the study showed that acrolein suppresses the immune system, causing damage to genetic material, and inhibits the body’s natural immune response via regulatory T cells, resulting in the acceleration of tumor growth.

“Inhalation is not the only relevant incorporation pathway,” said Jensen-Jarolim. “Acrolein can stick to anything, such as dinner plates, clothing or curtains and so can be incorporated much later on, via the skin, for example. It is therefore particularly important to protect children and pregnant women, especially in the domestic situation—–and this can only be done by completely eliminating any contact with cigarette smoke or its residues.”

Using animal models, the investigators found that acrolein did have a very slight beneficial effect on the immune system. Because acrolein suppresses the immune response, smokers are much less susceptible to allergies.

The findings indicate that acrolein is Janus-face, meaning it has 2 different faces.