Tobacco Asia

Volume 20, Number 2

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Page 18 of 67

tobaccoasia 19 nicotine patches, gums, and other medicinal prod- ucts are proof that nicotine itself is not addictive. In 2013, the US Food and Drug Administration (FDA) decided that some warnings and limitations specified in the directions for use on the labels of nicotine replacement products were no longer necessary to make sure they were used safely and effectively as they "do not appear to have signifi- cant potential for abuse or dependence". A recent Harvard study by Hillel R. Alpert, Israel T. Agaku, and Gregory N. Connolly also found that nicotine alone does not lead to addic- tion. What does is the additives found in cigarettes, and even e-cigarettes, particularly pyrazine. Misconception #3: Nicotine is a Poison. Fact: Fatal nicotine intoxications are rare. Bernd Mayer's study in 2013, "How much nicotine kills a human? Tracing back the generally accepted lethal dose to dubious self-experiments in the nineteenth century" questioned the previously held standard stating that the lethal dose of nicotine for an adult was 60 mg or less (30-60 mg) as there had been several documented cases where humans survived higher doses. This led to safety warnings that ingestion of five cigarettes or 10 ml of a dilute nicotine-contain- ing solution could kill an adult. Mayer found that the 60 mg dose would actually correspond to an oral LD50 (the amount of a poisonous substance required to kill 50% of those exposed) of around 0.8 mg/kg, or considerably less than the values de- termined for laboratory animals, which range from 3.3 (mice) to more than 50 mg/kg (rats). Mayer suggested that the lower limit causing fa- tal outcomes is, in fact, 500–1,000 mg of ingested nicotine, corresponding to 6.5–13 mg/kg orally. In conclusion to his findings, Mayer stated, "Nicotine is a toxic compound that should be handled with care, but the frequent warnings of potential fatalities caused by ingestion of small amounts of tobacco products or diluted nicotine-containing solutions are unjustified and need to be revised in light of overwhelming data indicating that more than 0.5 g of oral nicotine is required to kill an adult." Benefits of Nicotine In spite of having similar stimulant characteristics, nicotine has a chemical structure distinct from such phenylethylamines as amphetamine and ephedrine. As opposed to these substances, nico- tine is comprised of a pyridine ring connected to a pyrrolidine ring. Because nicotine is a weak base, it requires an alkaline environment to cross cell membranes. What makes the chemical structure of nicotine particularly remarkable is its resemblance to the molecule of acetylcholine, a compound that occurs throughout the nervous system, in which it functions as a neurotransmitter. And some rather remarkable qualities are imparted onto nicotine thanks to this similarity. Alzheimer's disease A meta-analysis of recent studies conducted by Stephen J. Heishman, Bethea A. Kleykamp, and Edward G. Singleton found that nicotine can help prevent Alzheimer's and Parkinson's diseases. Some studies have shown that smokers are less likely to suffer from Alzheimer's than those who do not smoke. This is because the receptors in the human brain which nicotine acts on are crucial for maintaining performance on a wide range of tasks, including memory. Patients with Alzheimer's have fewer of these receptors. Some studies show that providing the patients with nicotine helps to minimize the effect the disease has on their mental functioning. Nico- tine also helps improve the accuracy of short-term memory and improve the speed of recall for work- ing memory. Other studies have found that nico- tine administered via a patch or IV show positive results in Alzheimer's patients, including increased attention, learning, accuracy, and reaction time. Parkinson's disease Epidemiological studies have shown that smok- ing protects from Parkinson's disease, with an odds ratio of about 0.5 for smokers compared to non-smokers. The reason for this is the effects of nicotine has on dopamine neurons, the increasing loss of which is the cause of Parkinson's disease. Nicotine stimulates motor function and protects the neurons from dying. Cognitive benefits Many studies have shown that nicotine, like caf- feine, actually has such positive effects as increas- ing the speed of sensory information processing, easing tension and sharpening the mind. Nico- The nicotine molecule: Nicotine is a potent parasympathomimetic alkaloid found in the nightshade family of plants (tobacco, eggplant, tomatos, bell peppers, potatoes) and is a stimulant drug.

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