Vaping involves inhaling and exhaling aerosol, referred to as vapor, using a handheld electronic device such as an electronic cigarette or vape pen. In traditional cigarettes, tobacco burns to produce smoke. In vaping devices, an e-liquid or vape juice is heated to produce vapor.

E-cigarette aerosol is considered safer than cigarette smoke, but it still contains highly addictive and toxic nicotine, harmful chemicals, volatile organic compounds and cancer-causing agents.

Previous studies have shown that regular cigarette smoking can affect male fertility. In the latest study, published in the Spanish medical journal Revista Internacional de Andrología, researchers from Sivas Cumhuriyet University in Turkey evaluated the impact of vaping on the sexual health of male mice.

The study involved three groups of mice – one exposed to regular cigarettes, another exposed to vaping and a control group. The mice in the experimental groups were kept under bell jars and were exposed to their respective smoking technique twice a day for an hour each time.

The research team evaluated their urine cotinine levels, testicular weights, gonadosomatic index, sperm count, sperm motility and testicular histology and compared them with the values of the control group.

The sperm count of the e-cigarette group was 95.1 million sperm/ml and the traditional cigarette group was 89 million sperm/ml, while the control group showed an average of 98.5 million/ml.

The group exposed to cigarette smoke had the smallest and lightest testes compared to those exposed to e-cigarette vapor and the control group. Five out of eight mice exposed to vaping showed structural changes in the testes.

"It should be considered that although [e-cigarette] liquid has been introduced as harmless in smoking cessation studies, it could increase oxidative stress and cause morphological changes in the testicle," the researchers said. "To be a safe option in smoking cessation studies, its effect on people needs to be enlightened."