As of Dec. 20, 2019, the new legal age limit is 21 years old for purchasing cigarettes, cigars, or any other tobacco products in the U.S.

Did you ever wonder why so many of your friends who drink also smoke? Have you ever thought that you had successfully quit smoking, but the next time you had an alcoholic beverage you just had to have a cigarette?

Why is it so difficult for drinkers to quit smoking?

Alcoholics Smoke More Than Non-Alcoholics

We know from statistics and observations that:

People smoke more in places where alcohol is served

Alcoholics smoke more than non-alcoholics

Smokers are more likely to be binge drink ﻿ ﻿

Researchers at the Duke University Medical Center believe they have found one reason why alcohol seems to be so closely linked to smoking.﻿﻿

Behavioral Link Between Alcohol and Nicotine

"Epidemiological, clinical, and laboratory evidence clearly indicate a behavioral link between cigarette smoking and alcohol use," said Jed Rose, PhD, director of the Duke Nicotine Research Program and co-creator of the nicotine patch. "The combined use of cigarettes and alcohol presents health risks over and above the risks posed by smoking alone, and thus constitutes a serious public health problem which deserves additional research attention."

"In particular, understanding the pharmacological basis of the interaction between alcohol and nicotine could lead to the development of effective strategies for treating the drugs' dual-use," Rose said.

Smoking and Drinking Are Often Linked According to researchers: If you have more than five drinks a week, you’re two-and-half times more likely to smoke.

Compared to nonsmokers, smokers are three times more likely to drink to excess.

Moderate drinkers who smoke have a higher risk of heart, liver, and lung disease than those who only smoke or only drink. ﻿ ﻿

Nicotine Offsets Alcohol's Effects

In the past, investigators have speculated about the alcohol-nicotine association. Some research has indicated that it is because nicotine offsets the sedative effects of alcohol.

Drinking alcohol can slow reaction times and impair the performance of some visual tasks, but some studies have found that nicotine can counteract these deficits.﻿﻿

Both Increase Dopamine in the Brain

Both alcohol and nicotine increase concentrations of dopamine in the brain, so another theory is using nicotine and alcohol together increases the feeling of pleasure more than using either drug by itself.﻿﻿

Meanwhile, some neurobiological research has produced conflicting information regarding the nicotine-alcohol link. "Some have reported that ethanol increases the activity of the brain receptors that respond to nicotine, while others have indicated a dampened response of certain subtypes of the so-called nicotinic receptors in the presence of ethanol," the Duke researchers said.

To find out, Rose's investigators examined 48 volunteers who were regular smokers and who reported usually drinking at least four alcoholic beverages per week.

The participants were served either an alcoholic beverage or a placebo beverage. In one session, the volunteers were given a regular cigarette, but in another session, they were given a nicotine-free cigarette.

Alcohol Enhances Nicotine's Rewarding Effects

Compared to those who drank a placebo beverage, those who had alcohol reported that:

Alcohol enhanced the rewarding effects of nicotine

Alcohol enhanced the calming effects of nicotine

Nicotine-free cigarettes did not elicit the same response

The research suggests that it is nicotine itself, not other aspects of smoking, that is the critical ingredient in producing a positive response in people who drink alcohol.﻿﻿

Even a Small Amount of Alcohol Effects Nicotine

"A relatively low dose of alcohol—below that required to induce any measurable euphoria—was enough to increase participants' enjoyment of nicotine significantly," Rose said.﻿﻿ "In light of the current finding, it makes sense that so many people who have quit smoking relapse when they drink."

The researchers took the study a step further by giving the participants mecamylamine, a drug known to be a nicotine antagonist.

Mecamylamine Might Help Smokers Quit

"Mecamylamine might offer a novel treatment to help smokers who also drink alcohol quit both drugs as mecamylamine has been found to counteract the effects of both nicotine and alcohol, said Rose. "Such an approach to smoking cessation would work especially well for drinkers as it would dampen both desires," Rose said.

Such methods would be particularly useful for heavy drinkers and people with an addiction to alcohol, Rose added. Consideration of taking this medication must be made in close conjunction with your doctor, however, as it is still experimental.