Potentials problems with the use of hair include a strong influence of hair pigmentation on nicotine and cotinine binding and uptake Dehn et al. Nicotine and cotinine are bound to melanin. As a result, dark hair binds much more nicotine than does blond or white hair. This makes comparison across individuals difficult. Also, hair is exposed to nicotine and cotinine from sweat and from sebaceous gland secretions, and to nicotine from environmental tobacco smoke exposure. Washing the hair before analysis may reduce this problem of environmental contamination, but it is not likely to remove all environmental nicotine and cotinine.
Toenail clippings are easy to collect and store and represent cumulative exposure as nails grow at a rate of about 0. In a group of smokers, the average toenail biomarker concentrations were 5. Plasma levels of nicotine and cotinine were significantly but moderately correlated with toenail levels.
Thus, hair or toenail measurements of nicotine or cotinine or NNAL are promising biomarkers of long-term tobacco exposure. Dietary sources of nicotine have been alleged to be a potential confounder of cotinine levels used in measurement of secondhand smoke exposure.
Several foods contain small amounts of nicotine Siegmund et al. However, the levels of nicotine in foods are quite low. Based on nicotine levels in foods and the usual daily consumption of various nicotine-containing foods, it has been determined that the levels of cotinine produced by even a diet high in nicotine-containing foods is lower than that seen in individuals exposed to moderate levels of secondhand smoke Benowitz The primary alkaloid in tobacco is nicotine, but tobacco also contains small amounts of minor alkaloids such as anabasine, anatabine, myosmine, and others.
The minor alkaloids are absorbed systemically and can be measured in the urine of smokers and users of smokeless tobacco Jacob et al. The measurement of minor alkaloids is a way to quantitate tobacco use when a person is also taking in pure nicotine from a nicotine medication or a nontobacco nicotine delivery system.
This method has been used to assess tobacco abstinence in clinical trials of smoking cessation with treatment by nicotine medications Jacob et al. The optimal cut-point depends on the smoking behavior of the smokers and the magnitude of exposure to secondhand smoke. Using receiver operator characteristic curve analysis, the optimal cotinine cut-points were 3. The decline in the optimal cut-point since is likely due to the marked reduction in secondhand smoke exposure in the general US population.
Of note is that the cut-points are much lower for Mexican Americans than for whites or African Americans, most likely due to both more occasional smoking and lower exposure to secondhand smoke. We thank Marc Olmsted for his excellent editorial assistance. National Center for Biotechnology Information , U. Handb Exp Pharmacol. Author manuscript; available in PMC Oct Neal L. Author information Copyright and License information Disclaimer. Corresponding author. Benowitz: ude. Copyright notice. The publisher's final edited version of this article is available at Handb Exp Pharmacol.
See other articles in PMC that cite the published article. Abstract Nicotine underlies tobacco addiction, influences tobacco use patterns, and is used as a pharmacological aid to smoking cessation. Open in a separate window.
Table 1 Nicotine absorption pharmacokinetics of different forms of nicotine administration in single doses modified from Hukkanen et al. Pregnancy and Menstrual Cycle Pregnancy has a marked inducing effect in nicotine and especially cotinine clearance. Kidney Disease Kidney failure not only decreases renal clearance of nicotine and cotinine, but also metabolic clearance of nicotine Molander et al. Table 2 Biomarkers of tobacco exposure. Acknowledgments We thank Marc Olmsted for his excellent editorial assistance.
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Since one of the most well-known effects of nicotine is to advance concentration reviewed in Heishman et al. This is a complex but dull task in which subjects see a variety of stimuli and have to hit a button every time they see an "X," for example, Newhouse said.
A person who is concentrating will hit that button with the same speed every time the "X" pops up, while someone whose mind wanders will have a more variable response rate.
In the people on nicotine, response rate was more consistent than for those on placebo. It might be the caregivers who notice the benefit most, as their loved ones are better able to respond to requests, added Kelly Dineley of the University of Texas Medical Branch at Galveston, who also did not participate in the study. In a slew of secondary measures, the team also found that people on nicotine showed improvements in long-term recall.
Also, in a handful of reaction time and memory tests, the researchers observed an effect on the ApoE genotype. People who carried a double dose of the ApoE4 gene—and thus were at increased risk for AD—gleaned the most benefit from nicotine treatment. Similarly, a study of college students also found that ApoE4 carriers got a bigger boost in concentration powers from nicotine than did non-carriers Marchant et al.
It appears that nicotine, when given isolated from tobacco, can protect the brain from aging. Some of these surprising benefits can explain why some seem to need nicotine more than others, and ways to get these benefits without smoking. Nicotine, a powerful nootropic, is a natural liquid alkaloid found in several plants of the nightshade family. Potatoes, tomatoes, eggplants, and tobacco all contain nicotine. Tobacco has the highest nicotine content, making it capable of a significant effect on living beings.
When you think of nicotine, the first thing that comes to mind is cigarettes and tobacco products. Many people assume that nicotine is a harmful ingredient in tobacco products, which are known to cause several serious illnesses including cancer. However, nicotine in itself is not harmful and has been associated with several health benefits.
In fact, nicotine is the least harmful among the substances found in cigarettes. Nicotine, when used independently in the form of a standalone patch, can help cognitive function without requiring exposure to any of the dangerous toxins found in cigarettes.
It appears that using nicotine can enhance cognitive capacity and offer neuroprotection, some scientific evidence suggests. For example, using nicotine is known to help people in solving complex calculations, considering analytical problems, producing technical writing, and taking exams.
Cigarettes contain tobacco and several other harmful chemicals which actually make this product hazardous to health. While nicotine is considered a highly addictive drug, there is a lack of significant evidence to support the idea that it is carcinogenic. Cancer has been associated with nicotine primarily because it is present in cigarettes. Studies suggest that the various harmful chemicals in tobacco smoke are what makes smoking so hazardous to health. Hence smoking should never be seen as a healthy means of nicotine intake.
Their research was published in the Open Access Journal of Toxicology. The animal models were divided into three control groups based on the level of nicotine concentration they received. One control group did not receive nicotine. The groups which received the low and medium nicotine doses did not show any level of the drug in their blood. Likewise, the animals did not experience any changes in body weight, food intake, or brain receptors related to the drug.
In contrast, the group that received the highest concentration of nicotine gained less weight, ate less, and had an increase in brain receptors, showing that higher doses of nicotine reach the brain and impact behavior. However, high doses of nicotine did not result in any behavioral side effects such as anxiety, which researchers had anticipated. Instead, a high concentration of the drug appeared to reduce anxiety levels.
The result from the research indicates that nicotine can prevent weight gain in aging animals. It has not yet been determined whether a lower body mass index reduces degeneration of the brain. Clinical trials make it clear that nicotine possesses the ability to suppress appetite. Further study is required to explore more potential benefits of nicotine. However, Winzer-Serhan cautioned against smoking and made it clear that nicotine in this form has serious side effects which outweigh its benefits.
She also urged people to stay away from nicotine products. Though the clinical results were intriguing, further trials are required to understand how nicotine affects behavioral changes.
Since the benefits of nicotine do not outweigh its potential risks, especially children and adolescents are strongly advised to stay away from this drug. Nicotine promotes wakefulness, alertness, motivation, and creativity.
The following are some of the potential benefits of this nootropic drug and its associated effect on health:.
These benefits of nicotine are observed only when the drug is taken alone. Nicotine addiction appears to occur through the dopamine system — killing the dopaminergenic neurons in animal models leads to a cessation of self-administration. Interestingly, the dose-response curve of nicotine quickly flattens out in rats — ie.
This is in contrast to drugs such as cocaine or amphetamines. Nicotine intake in humans usually lies in a narrow range , between mg per day. The addictiveness of nicotine is modulated by the intensity and duration of nicotine exposure.
In general with addictive substances, the more quickly it is delivered, the more dopamine and reward substances are produced. Another reason that fast delivery ie. Nicotine enters the brain only seconds after a person takes a draw from a cigarette.
Finally, nicotine receptors sensitize and desensitize fairly quickly. A cigarette administers about 2 mg of absorbed nicotine. As a nootropic, limiting to mg a day is recommended. Delivery methods: risk for addictiveness from highest to lowest:. Nicotine mouth spray. Chewing gum when properly taken. Lozenges when properly taken, do not chew.
Nicotine patches [these administer nicotine over hours, resulting in significantly lower chance of addiction than all the above, but on the flip side some users report not seeing as much cognitive benefits].
I got the idea to take nicotine as a nootropic after reading an interview with Oxford transhumanist philosopher Nick Bostrom. When asked if he has ever taken any cognitive enhancers, he said he experimented with nicotine gum. In his book Superintelligence he also mentions that nicotine gum helped him write the book. I have developed a somewhat more nuanced view on addiction. For instance, SSRIs carry a large dependence but are technically not addictive in the same way that hard drugs are.
An important point when considering nootropics is to understand that addiction, construed in the general sense, is not necessarily a bad thing. For instance, many of us find that the benefits of caffeine outweigh the dependence it entails. The same may hold for more extreme nootropics that are known to be addictive, such as modafinil.
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