Results are published in the November issue of Alcoholism: Clinical & Experimental Research.
"Tobacco is one of the most heavily used addictive drugs," said M. Yanina Pepino, a researcher at the Monell Chemical Senses Center in Philadelphia and corresponding author for the study, "leading to an increased risk of lung and heart diseases and a variety of cancers." In fact, lung cancer has surpassed breast cancer as the leading cause of death among US women, she added.
"Women who smoke also have an increased risk of cervical cancer, reproductive and pregnancy complications, and early menopause," said Pepino. "Compared to men, women are also more sensitive to some of the harmful effects of smoking: lung disease progresses more quickly in women, and they are at a greater risk for coronary heart disease, especially if they smoke while using oral contraceptives."
Despite the greater health risks, women derive more pleasure than men from the smell and taste of cigarettes, are more likely to smoke as a way to reduce stress and feelings of depression, and use smoking as a diet tool. In fact, said Pepino, many women who try to quit smoking often relapse because of concerns about gaining weight.
At the same time, said Alexei B. Kampov-Polevoy, research assistant professor of psychiatry at The University of North Carolina at Chapel Hill, sweet taste is one of the first pleasures we experience, for example, mother's milk. "There is growing evidence that our hedonic response to sweet taste reflects integrative activity of the brain-reward system, specifically, of the brain opioid system," he said. "Distortions of perception of sweet taste and craving for sweets have been reported in patients with various psychiatric conditions - depression, substance abuse, eating disorders, premenstrual syndrome, several forms of obesity etc. Considering that hedonic response to sweet taste is at least in part regulated by genetic mechanisms, and that differences in response can be detected at birth, this trait may be a potential marker of the risk for many psychiatric conditions."
For this study, researchers examined two groups of women between 21 and 40 years of age: 27 current smokers (18 had a positive family history of alcoholism), and 22 women who had never smoked in their lives (9 had a positive family history of alcoholism). Each woman was tested on two days separated by one week. Cravings for specific foods and, for the smokers, cravings for cigarettes, were measured. Smokers were given nicotine-containing cigarettes during one test session, and nicotine-free cigarettes during the other. Thirty minutes after smoking for smokers, and 30 minutes after arrival for nonsmokers, study authors assessed sucrose thresholds and preferences during both test sessions.
"Cigarette smoking and having a family history of alcoholism had different effects on sweet-taste perception and food cravings," said Julie A. Mennella, a senior researcher at Monell and coauthor of the study. "Women who smoked cigarettes were less sensitive to sweet taste than women who never smoked. This means that women who smoke required higher concentrations of a sweet solution in order to detect sweet taste; we also found that the more years a woman has smoked cigarettes, the less sensitive she will be to sweet taste." Whether the reduced sensitivity for sweet tastes helps smokers control their weight is an important question that needs further study, she added.
According to Kampov, the second finding - that women with a family history of alcoholism preferred higher levels of sweetness and craved sweet-tasting foods more often - is also noteworthy He said it confirms earlier reports that hedonic - or pleasurable - response to sweet taste is associated with a genetic risk for alcoholism.
"We may now use this knowledge to, one, identify individuals at high risk for alcoholism and two, study biological mechanisms involved in the development of alcohol-use disorders," said Kampov.
Mennella and Pepino recommended that future research on the effects of smoking on food habits and cravings should take into account family history of alcoholism, given its association with sweet liking and the increased likelihood of developing a tobacco-related disorder.
On a more practical level, Pepino warns that the negative effects of smoking are far-ranging. "The study suggests that cigarette smoking dulls sweet-taste detection and is associated with increased food cravings, especially for starchy carbohydrates and foods high in fat," she said. "We found that food cravings were associated with nicotine dependence ... the more intense the cravings for cigarettes, the more frequent the cravings for foods high in fat and carbohydrates."