He points to studies of snus - a chewable tobacco product that is popular mainly among men in Sweden and is gaining traction elsewhere - which do not generally show a detectable rise in heart problems among people who use it. “Nicotine is a minor player with respect to smoking-induced cardiovascular disease,” says Benowitz. Some researchers think that nicotine has only a small effect on heart health. A system in Laura Crotty Alexander’s laboratory exposes mice to aerosols generated by vaping devices. Nicotine has also been implicated in stoking inflammation in heart and lung tissue, says Laura Crotty Alexander, a pulmonary biologist at the University of California, San Diego in La Jolla.
Nicotine can knock this delicate timing off and promote abnormal heart rhythms, says Bhatnagar. When nicotine is inhaled, it changes the electrical conductivity of the heart that keeps it beating in sync. “We believe that much of the cardiovascular effects of smoking are because of nicotine,” says Bhatnagar. Researchers at the American Heart Association think that the stress nicotine puts on the heart is concerning. What these acute impacts mean for long-term cardiovascular health, however, is disputed. This process happens whether nicotine is inhaled from a cigarette or an e-cigarette, or chewed in the case of smokeless tobacco. These effects are partly due to nicotine, which triggers the release of various neurotransmitters and hormones such as epinephrine. When a smoker tugs on a cigarette, their heart pumps harder, their blood pressure increases and certain blood vessels dilate or constrict. In this new context, delineating the effects of a purer stream of nicotine is important, and numerous associations are being made, including purported impacts on heart health, cancer and brain development. Vaping could provide a nicotine hit without the cancerous baggage, but it has become fiercely controversial owing to concerns that people who have never smoked - especially adolescents - will become hooked. Interest in the effects of nicotine is blossoming, partly because of the proliferation of e-cigarettes, or vapes. “We’ve done a poor job of dissecting out the various components of cigarette smoke,” says Gerry McElvaney, a pulmonary physician at the Royal College of Surgeons in Ireland, Dublin.
With so many toxic compounds in tobacco smoke, separating nicotine from the rest of the noxious milieu has been a struggle. “It is hard to sort out because most nicotine exposure data comes from cigarette smoking,” says Neal Benowitz, a physician and nicotine researcher at the University of California, San Francisco. “It’s not a harmless compound.”Įvidence for direct deleterious effects of nicotine consumption is limited.
“It changes lots of functions in our bodies,” says Maciej Goniewicz, a nicotine pharmacologist at Roswell Park Comprehensive Cancer Center in Buffalo, New York. Receptors that respond to nicotine are found not just in the brain, but also in tissues such as muscle. “It has been said since the 1950s that people smoke for the nicotine and die from the tar,” says Aruni Bhatnagar, director of the American Heart Association’s Tobacco Regulation and Addiction Center at the University of Louisville, Kentucky.īut some researchers think that nicotine’s influence on health could extend beyond just its addictive nature. The positive feelings this produces are why nicotine is addictive, and one reason why smokers crave cigarettes.Īlthough the addictive qualities of nicotine are well known, the damaging health effects of smoking are usually attributed to more-obvious toxins such as polycyclic aromatic hydrocarbons (PAHs), cadmium and the sticky brown tar left inside the lungs. In people, nicotine activates similar receptors throughout the nervous system, including those in the brain that affect the release of the feel-good molecule dopamine. It poisons insects by binding to acetylcholine receptors in their nervous systems and causing their nerves to fire uncontrollably. Nicotine is an alkaloid compound made by plants to deter herbivores, and it has been used as an insecticide. However, the most famous ingredient of a cigarette - nicotine - has generally not been considered a culprit in these health effects. Their combined effects on health are well known: cancer, heart disease, stroke, chronic obstructive pulmonary disease and many more conditions. After a few vigorous puffs of a burning cigarette, a smoker’s lungs will be filled with a toxic cloud of more than 5,000 different substances.
0 kommentar(er)
