So-called “third-hand” cigarette smoke could increase the risk of type 2 diabetes, scientists have claimed.
Exposure to toxic chemicals left behind on sofas, carpets, clothing and hair resulted in mice developing insulin resistance, a precursor to the condition, a study has found.
Researchers say the combination of this smoke alongside high-fat diets make the chances of getting type 2 diabetes “worse”.
Youngsters at higher risk
Young children are at particular risk for contact with third-hand smoke, the research published in the journal PLoS One also found.
This new body of research into third-hand smoke comes on the back of long-standing evidence demonstrating a link between cigarette smoking and an increased risk of cancer.
The researchers concluded: “If confirmed in humans, these studies could have a major impact on how people view exposure to environmental tobacco toxins, in particular to children, elderly and workers in environments where tobacco smoke has taken place.”
Accumulation of second smoke on surfaces
Professor Manuela Martins-Gree, a cell biologist at the University of California, Riverside, took part in the study.
She said: “Third-hand smoke is the accumulation of second-hand smoke on the environmental surfaces. So, as the smoke is coming out of the ends of the cigarettes, it’s then depositing on the sofas, the carpets, the clothing, the hair … all the surfaces … even if it’s wood. And it’s not just accumulating in the homes, [but] in the cars as well.”
The researcher said young children were at risk for contact with third-hand smoke because they crawled along the carpet and put their hands in their mouths, adding that toxic fumes can also spread throughout a building via ventilation systems.
Cigarette residues easily absorbed into the body
Martins-Green and her colleagues discovered that cigarette residues are easily absorbed into the body. She said: “And those chemicals are actually absorbed through the skin very rapidly. So they go in circulation and they go all over the body, and that’s one thing you don’t want.”
The effects of third-hand smoke on mice, using smoke machines in the enclosures to simulate second-hand smoke, was studied.
The team discovered the first signs of a health problem in the animals’ livers, an increase in lipids or fats seen in people at high risk of type 2 diabetes. The amount of glucose in the mice was then measured, and found that it, too, was elevated, as were levels of insulin, a hormone used by the body to convert glucose into energy.
Martins-Green said the process can start in childhood, with doctors now seeing teenagers with elevated blood sugar level.
She added: “A very relevant aspect of our science … is that when you feed these mice high-fat diets like the teenagers and young adults eat, you know, these hamburgers and tacos and all these things laden with fat, that we find that the effects of the third-hand smoke make the situation – the disease situation – worse.”
Martins-Green’s team will next be looking for a link between third-hand smoke and liver damage.
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