A new study from Texas A&M University and published in the Journal of Toxicology suggests that oral nicotine may actually prevent the brain from aging, and thus developing Alzheimer’s and Parkinson’s disease.
Researchers think that the potential brain-protecting effects may be linked to the chemical’s ability to suppress appetite. Smokers are far less likely to be overweight or obese, which, in a somewhat twisted way, provides some benefit to the brain. When people don’t eat too much, their brains don’t shrink as quickly, keeping them mentally sharper for longer. 
Researchers, however, are adamant that this doesn’t mean they are encouraging people to smoke.
Lead researcher Dr. Ursula Winzer-Serhan of Texas A&M stated:
“I want to make it very clear that we’re not encouraging people to smoke.
Even if these weren’t very preliminary results, smoking results in so many health problems that any possible benefit of the nicotine would be more than canceled out. However, smoking is only one possible route of administration of the drug, and our work shows that we shouldn’t write-off nicotine completely.
Although the results are intriguing, we would need large-scale clinical trials before suggesting anyone change their behavior.” 
The researchers particularly discourage the use of nicotine in children and adolescents, partially due to its highly-addictive nature.
Read: Obesity in Midlife Linked to Earlier Onset of Alzheimer’s Disease
For this experiment, mice were given nicotine in their drinking water at low, medium, and high doses. Those who received the low and medium doses of nicotine showed very little change in their behavior and food intake. However, those who were given the large amounts of nicotine showed both a decrease in weight and a decrease in the amount of food they ate.
Researchers also found that there were no signs of increased anxiety in the mice that received the higher doses. But, they do recognize that nicotine and cigarette smoking may calm some people down and may raise the level of anxiety in others. As a result, they are wary in prescribing it as a weight loss substance because of the fact that it can alter behavior.
And while it is conclusive that nicotine can help curb weight gain, it is not yet conclusive that it will help slow brain degeneration.
“At the end of the day, we haven’t proven that this addictive drug is safe – and it certainly isn’t during childhood or adolescence – or that the benefits outweigh the potential risks,” Winzer-Serhan adds.
 Daily Mail
 Nature World