New Evidence Suggests Nicotine Could Be Neuroprotective

Though the negative health effects of smoking nicotine products have been well established, new research conducted at Texas A&M suggests that on its own, nicotine could be a neuroprotective agent for the aging brain. These neuroprotective properties could make nicotine a useful drug in preventing neuronal degeneration indicative of Alzheimer’s and Parkinson’s disease.

According to Dr. Ursula Winzer-Serhan, an associate professor at the Texas A&M College of Medicine, nicotine’s ability to protect the brain could be due to its effects as an appetite suppressant. The research was published in the Journal of Toxicology.

In order to study the effects of nicotine on food intake, Winzer-Serhan and her colleagues administered different doses of nicotine to three groups of mice. The doses – low, medium and high – were equivalent to the amount of nicotine consumed by different smokers. A fourth control group received no nicotine treatment.

The animal models in the low and medium nicotine groups showed no change in blood nicotine concentration, food intake, body weight or number of nicotinic acetylcholine receptor in the brain. The mice that received the highest concentration of nicotine however, consumed less food, gained less weight, and showed an increase in the number of receptors in the brain.

This result suggests that at higher doses, nicotine is able to enter the brain where it has a measurable impact on behavior. Encouragingly, the researchers reported that these higher doses of the drug did not cause any negative behavioral side effects, such as anxiety.

“Some people say that nicotine decreases anxiety, which is why people smoke, but others say it increases anxiety,” said Winzer-Serhan. “The last thing you would want in a drug that is given chronically would be a negative change in behavior. Luckily, we didn’t find any evidence of anxiety: Only two measures showed any effect even with high levels of nicotine, and if anything, nicotine made animal models less anxious.”

The researchers now plan to test the drug in older animal models to determine whether nicotine’s appetite suppressant properties translates into lower weight animals with healthier brains. Winzer-Serhan and her team also hope to determine whether nicotine has other health effects aside from its ability to suppress appetite.

“I want to make it very clear that we’re not encouraging people to smoke,” said Winzer-Serhan. “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 cancelled 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. 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.”