It is very well known that alcohol and cigarettes are ancient companions, but the reason for the link is not well understood. Scientists recently discovered that both these chemicals affect the same protein in the brain, explaining why alcoholics are seven times as likely to also be heavy smokers when compared to casual drinkers. According to researchers, alcohol influences the acetylcholine receptors in the brain, making them less sensitive to the influence of nicotine. Since the same receptors give the 'feel good' response from smoking also, they now need more nicotine to get the same feeling of satisfaction.