Can Nicotine Protect An Aging Brain?
Independent of tobacco products, nicotine shows promise in offering protective benefit to aging brains, and even potentially warding off Alzheimer's or Parkinson's disease.
In a study published in the Journal of Toxicology, Ursula Winzer-Serhan, Ph.D. and colleagues reported that nicotine's neuroprotective ability may be due in part to the substance's appetite suppression ability.
The researchers used animal models to study the effects of nicotine on aging brains. They set up three groups, each one receiving different levels (low, medium and high) of the substance in their drinking water to correspond to smoking frequency. Another group was also in place to serve as control for the experiment.
Based on the results (PDF), the groups that were given low and medium doses of nicotine didn't have traces of the substance in their blood. Additionally, the subjects didn't manifest changes in their food intake nor did they show a difference in the number of brain receptors that act on nicotine.
The group that received high doses of nicotine, on the other hand, not only ate less and gained less weight, but they also had more nicotine-related brain receptors. This indicates that the substance can get into the brain at high doses, possibly impacting behavior. Even at high doses, however, nicotine didn't appear to have adverse behavioral side effects, like increased anxiety. The researchers were particularly concerned that behavioral side effects would show when high doses of the substance were administered.
"The last thing you would want in a drug that is given chronically would be a negative change in behavior," said Winzer-Serhan.
According to her, some people smoke because they feel nicotine decreases their anxiety. However, others claim it makes the condition worse. In the study at least, taking nicotine made the animal subjects less anxious.
While early results have shown that nicotine can keep weight gain in older individuals at bay, the researchers were not able to find any direct proof that lower body mass indices leads to drop in brain degeneration.
A lot remains to be studied about nicotine so the researchers warn about consuming the substance, reiterating they are not encouraging people to smoke. Nicotine is addictive, after all, and smoking tobacco has been associated with a myriad of health problems.They do want people to take note though that there are other ways to administer nicotine beyond tobacco use.
"[O]ur work shows that we shouldn't write-off nicotine completely," added Winzer-Serhan.
For future research, she suggests large-scale clinical trials to fully assess nicotine's effects on the body, particularly those that are behavioral.