How Does Smoking/Nicotine Affect Appetite?

Smoking is the number one cause of death in the United States and other developed countries due to the effects of the highly addictive nicotine that cigarettes contain. Cigarettes are responsible for causing a variety of diseases ranging from lung cancer, heart diseases, and chronic bronchitis among others. However, one issue that smokers find appealing about smoking is that on average smokers are skinnier than the nonsmokers are. In the 1920s, tobacco companies took advantage of the fact that women wanted to lose weight and lured them to engage in smoking to control their weight (Gatley, 2003). Moreover, there is an inevitable weight gain among a majority of individuals that quit smoking, and hence this becomes a major impediment to individual’s decision to choose to quit the deadly habit of smoking. Researchers in the past have been faced with the responsibility to explain the relationship between weight loss and smoking; it is this that led to studies on the effect of smoking, and subsequently the nicotine contained in the cigarette on the appetite of individuals (Seeley & Sandoval, 2011). It is also common knowledge that a majority of weight gain cases are because of increased of uncontrolled appetite. Therefore, the research below indicates the various studies and evidence on how tobacco smoking and the nicotine contained in the cigarettes affects appetite.

It is also fundamental to note that smoking and obesity are the leading cause of mortality and morbidity globally. A case of co-occurrence between overweight and smoking has considerable consequences on the health of an individual. In fact, the a Framingham study indicated that the life expectancy of an obese smoker is up to 13 years less than that of a normal weight nonsmoker (Seeley & Sandoval, 2011). However, the relationship between obesity and smoking is not yet completely understood and hence more researches are being conducted. It is more so confusing for researchers because, majorities of smokers end up shedding a lot of weight due to reduced appetite.

Nicotine acts not just as a stimulant in the body of an individual but also as an important appetite suppressant. The act of smoking also induces a behavioral change that leads to a reduction in the eating habits of a person. A cigarette may totally reduce the urge that one had to engage in snacking (Seeley & Sandoval, 2011). There are indications that smoking may deter appetite by the fact that it may make the food to be less tasty to some of the smokers discouraging them from engaging in the eating. Some researchers indicate that the nicotine may act on the hypothalamus that controls eating to induce satiety in an individual. It has been proven among the mice according to research published in Yale’s Journal of Science (Mineur et. al., 2011).

Nicotine acutely increases the expenditure energy ad could lead to a major reduction of an individual’s appetite. It gives an explanation as to why smokers have relatively lower body weight than the nonsmokers. It is also the reason smoking cessation is usually followed by an increase in the body weight of an individual. There is also a belief among some of the smokers that smoking is the ideal way to control the body weight of an individual. However, some researches indicate that the heavy smokers or rather those that smokes a lot of cigarettes in a day have a greater body weight than those that smoke lightly. It further clusters the relationship between smoking, appetite and body weight (Seeley & Sandoval, 2011).

The nicotine receptors in the human brain have 15 subsections and can combine in some ways to form different receptors that have different jobs including causing a slump in the appetite of an individual. The Nicotine binds itself to one another, and the combination creates a spur of events that may lead to addictive tendencies if the cigarettes, increased blood pressure, a feeling of relaxation and the decrease in the appetite of an individual (Seeley & Sandoval, 2011). Researchers have over time suspected the relationship between the nicotine receptors and the decline in appetite and asserted that it worked through the reward and behavior reinforcement concept. It is because; the body considers the food and the nicotine as rewards. However, some researchers have disagreed with the idea arguing that appetite has its pathway and hence cannot be affected by the nicotine receptors.

In a study by a behavioral neuroscientist at Yale University called Marina Picciotto on whether activating α3β4 nicotine receptor on a mouse there were antidepressant effects. However, a colleague of the researcher realized that as Marina was conducting the research the mice lost its appetite considerably. Before the research, there was no evidence that the nicotine receptors could affect the food intake of an organism. Picciotto and her colleague Mineur went on to demonstrate that the nicotine binds itself with α3β4 that send a signal to the rest of the brain that indicated satiety hence affecting its appetite (Mineur et. al., 2011). In fact, the signal that the brain sends because of the receptors combination is the same as the signal sent to the brain when an organism has eaten enough when normal. The mice used in the study ate half as much as the ones that did not receive the drug. The mice administered with the nicotine lost 15 to 205 of their body weight in a month. Therefore, as a solution to the problem faced by those that want to quit smoking but are afraid of gaining weight, Picciotto suggests that the pharmaceuticals could develop a drug that targets to suppress appetite. In fact, the approach would be healthier than engaging in nicotine uptake to reduce body weight (Mineur et. al., 2011).

According to Bray, (2000), Nicotine, just as is the case with other anorexigenic substances, which include leptin and insulin, have a general opposite effect on the regulation of the sympathetic outflow and appetite of an individual. As a result, nicotine leads to elevated blood pressure, gastric motility, and increased heart rate while at the same time leading to a decreased food intake. The sensory, autonomic, and enteric neurons have potentially significant loci for the nicotine-induced changes in the appetite of an individual and the feeding patterns. The peripheral tissues involved in the regulation of food intake receive their information from the sympathetic and the parasympathetic neurons controlled by the cholinergic transmission. All the autonomic have subunits that are potentially affected and activated by the nicotine intake of an individual (Mineur et. al., 2011).

A research by Mineur et. al. (2011) indicated that Nicotine reduced the appetite of an organism through the activation of POMC neurons. The researchers used a combination of pharmacological, molecular genetics, and other feeding studies. The study found out that the activation of hypothalamic α3b4 nicotine acetylcholine receptors led to the activation of pro-opiomelanocortin (POMC) neurons. The neurons subsequently result in the activation of melanocortin 4 (MC4) receptors that are fundamental for nicotine-induced decreases in the food intake of a mice. The study demonstrated that nicotine reduced the level of food intake and subsequently the body weight of an organism by influencing the hypothalamic melanocortin system. It recognizes vital molecular and synaptic mechanisms involved in nicotine-induced decreases in appetite.

Nicotine triggers a pathway in the brain that suppresses the appetite of an individual. In experiments to look for chemicals that could treat depression, by Marina Picciotto a psychiatrist professor from Yale with a colleague scientist Yann Mineur, who administered a Nicotine to the mice and realized that they significantly reduced their appetite (Mineur et. al., 2011). The researchers focused on the POMC cells of the hypothalamus involved in the regulation of eating behavior in the brain to find out how it was affected by administration of nicotine. They discovered that the nicotine made the POMC cells more active (Mineur et. al., 2011). They looked into a receptor that do not make a person feel good and are involved in the fight or flight response that occurs to an organism when they perceive a threat. The fight or flight response is that the body wants to preserve energy and effort to handle the threat and hence to eat is not a priority. Picciotto gives an illustration that an individual would not take a time to eat in the perception of a life-threatening event but would rather find a way out of it. She provides an example of when a tiger threatens one, eating is the last thing that they would engage in at that point (Mineur et. al., 2011).

A study by Jessen et. al. (2005) indicated that caffeine consumption enhances the appetite suppressant characteristic of nicotine intake. In the research, they found out that hunger and overall food intake had an adverse association with an increased dosage of nicotine. On the contrary, they discovered that satiety and a feeling of fullness were positively correlated with an increase in the nicotine increase. Caffeine taken by the individual amplified the effect that nicotine had on satiety of an individual. Among some of the subjects in the study, the combination of caffeine and nicotine caused nausea among some of the subjects (Jessen et. al., 2005).

Nicotine can lower the insulin levels in an individual that subsequently may result to reduced cravings for sugary foods. Moreover, the nicotine-induced effects of adrenaline on the stomach’s musculature may lead to temporary feelings of subsided hunger in a person. Other studies have indicated that smokers expend more calories while engaging in the activity, which points to, that the smokers have a heightened metabolic rate (Seeley & Sandoval, 2011). 

For individuals that would like to control their weight, smoking may have positive short-term effects such as the reduction of the appetite of an individual. it is because, as a result of smoking, over 90% of the nicotine contained in it enters the body of the smoker. On reaching the brain, it affects several brain hormones including acetylcholine, adrenaline, dopamine, beta-endorphin among others. The positive effect that results from the hormonal changes is the reduction in appetite and a dwindle in the sense of smell and taste. It is this that leads to the feeling of foods having lost taste and hence the cravings for most foods are no longer present.

The effect of smoking on appetite is also emphasized by a research that indicates a correlation between smoking and dieting. According to the University of Florida study of about 8,000 adolescents, research, teenage girls that engaged in dieting were more likely to smoke than those that did not. Additionally, teenagers who begin dieting were twice more likely to start smoking as well. The study indicated a link between smoking and a reduction in the appetite of the smoker. There is also a possible link between eating less and the abuse of drugs such as tobacco smoking according to the study. The research did not find any linkage between dieting and smoking among boys, but it is because, they are less likely to diet and smoke (Chiolero et. al, 2008).

Tobacco use and other nodes of nicotine intake such as chewing gums containing it have been adopted in the past to control weight among some individuals. It is because, there is reported a reduction in the appetite of a person following the intake of the nicotine. However, smoking instead of eating is not an appropriate tradeoff given the major risk that comes with nicotine consumption. It is not wise for any person to take up smoking to control weight although obesity is a major threat to an individual’s health as well. In fact, smoking is of a greater threat to a person than obesity (Chiolero et. al, 2008). Research indicates that smoking leads to reduced taste and an effect on the hormones and cells in the hypothalamus that regulate the food intake of an individual. it is the changes that result to decreased appetite either through tampering with the taste of the food or making the body perceive satiety and fullness with little food intake. There are, however, not studies that are yet to ascertain the effect of the nicotine on humans since the studies were done using mice. However, the researchers that indicate a reduction in appetite through the alteration of the receptors in the brain is a major step towards developing safer and more healthy methods of controlling weight through the change of a person’s appetite (Chiolero et. al., 2008).