The cigarette is probably the most widely used nicotine delivery device on the market. However, the tobacco industry has released a host of other kinds of tobacco-containing products, as well as non-tobacco nicotine-delivery products. How do these products compare to cigarettes? Do people who use these products also get addicted? A brief review of some of these products can shed some light on these questions.
The following topics will be discussed in this section:
- Reduced-nicotine/tar cigarettes: a healthier alternative to regular cigarettes?
- Smokeless tobacco: can it cause addiction and cancer?
- Nicotine-delivery products: are they safer?
Reduced-nicotine/tar cigarettes: a healthier alternative to regular cigarettes?
Tobacco companies have created cigarettes that are supposed to deliver a lower amount of nicotine and tar (carcinogens) compared to regular cigarettes. Although the labels on packs of these cigarettes show how much nicotine is in each cigarette, the labels are misleading.
The nicotine and tar contents are determined with “smoking machines”, which do not reflect how people smoke. For example, reduced-nicotine/tar cigarettes were designed to have tiny air holes in the filter section that help dilute the smoke and nicotine. The idea is that, in theory, users will inhale more air and less nicotine and tar.
However, the air holes are positioned strategically so that when a smoker actually holds the cigarette, his/her fingers naturally cover the tiny air holes. Thus, the smoker inhales more of the nicotine and tar and less air. The smoking machine does not block these air holes, so the nicotine and tar content measured by the machine are actually lower than what an actual smoker receives.
When people smoke cigarettes, or use any tobacco product, they use enough of the tobacco product to obtain a certain level of nicotine in their brains that makes them feel good. As discussed previously, nicotine binds to nicotinic receptors, activating the neurons to fire electrical signals in the part of the brain responsible for pleasurable feelings. So, to get the expected effects of nicotine, there must be enough of the drug in the brain to bind to the receptors.
Figure 3.1 Smokers smoke cigarettes to attain an effective nicotine level. The reduced-nicotine cigarettes on the right have less nicotine compared to the regular cigarettes on the left. People tend to smoke more of the reduced-nicotine cigarettes to get the same level of nicotine in their brain. In doing so, they inhale more carbon monoxide and carcinogens.
What do you think will happen if the cigarette contains less nicotine? Take a look at Figure 3.1. Smokers of the reduced-nicotine cigarettes automatically compensate by inhaling more often and taking longer and deeper puffs to get the needed nicotine. In the end, the smoker may actually smoke more of the reduced nicotine/tar cigarettes in order to receive the amount of nicotine they need.
These reduced-nicotine cigarettes are also labeled with less tar, or carcinogens. But because the smoker needs to inhale more deeply, take more puffs, or smoke more of these cigarettes to get the needed amount of nicotine, they also end up inhaling more carcinogens—even if the cigarettes do have less tar. Not only do they inhale more carcinogens, they also inhale more carbon monoxide too.
As discussed above, it only takes one carcinogen and one mutation to cause cancer, regardless of how many carcinogens one might inhale. In fact, scientific studies have found that there is actually no statistical difference in health risk of smokers of reduced-nicotine/tar cigarettes versus regular cigarettes.
Smokeless tobacco: can it cause addiction and cancer?
There are a number of other tobacco products on the market besides cigarettes. Different products appeal to different people for a variety of reasons. Such products include smokeless tobaccos (including chewing tobacco, Snuff, Snus, and lozenges), cigars, little cigars, pipes, and water pipes.
Each of these products containing tobacco is harmful because they all contain nicotine and carcinogens. Let’s look at a few examples of smokeless tobacco.
- Regular or menthol cigarettes
- Reduced nicotine/tar cigarettes
- Cigars, little cigars
- Chewing tobacco
- Snus tobacco
- Water pipe
- Tobacco lozenges
One of the main types of smokeless tobacco in the United States is chewing tobacco. Chewing tobacco consists of whole or shredded tobacco leaves that are placed between the cheek and gum of the user.
Nicotine and other chemicals are released from the tobacco leaves into the saliva when the user chews on the tobacco (hence the term “chewing tobacco”). The nicotine and other chemicals in tobacco are absorbed through the cheek cells into the bloodstream. In addition, the chewing of the tobacco produces excess juice in the mouth, which the user must either spit out or swallow.
A common misconception about smokeless tobacco is that it is not as harmful as smoking because it contains less harmful chemicals. This is not the case for smokeless tobacco, otherwise known as “chew” or “dip”.
Smokeless tobacco contains at least 30 known cancer-causing chemicals. The most harmful of these chemicals are the nitrosamines, which are made during the fermenting and aging process of tobacco (some nitrosamines can be generated from the breakdown of nicotine).
Research shows that people who use smokeless tobacco may actually be exposed to higher levels of the nitrosamines, depending on the brand and length of time held in the mouth. One of the main reasons for the higher amount of toxins in the body is that the tobacco stays in the mouth longer than one smokes a cigarette, so the harmful chemicals have more time to be released into the body.
Figure 3.2 Carcinogen exposure from smokeless tobacco. Users of smokeless tobacco can receive more nitrosamine carcinogens and nicotine compared to smokers.
Although smokeless tobacco contains fewer carcinogens compared to cigarettes, all it takes is one carcinogen to cause a mutation that leads to cancer. Contrary to popular belief, smokeless tobacco can actually lead to many types of cancers, including oral, pancreatic, esophageal, and even lung cancer.
Long-term use of smokeless tobacco can also cause bleeding of the gums and mouth, separation of the gums from the teeth (which over time could lead to teeth decay), yellowing of the teeth, bad breath, increased heart rate, and high blood pressure.
Users of smokeless tobacco also receive more nicotine compared to smoking a cigarette. Because smokeless tobacco users tend to leave the tobacco in their mouths for about 30 minutes, the amount of nicotine absorbed into the body from a typical tobacco chew or “dip” is approximately 3-4 times the amount absorbed from smoking a single cigarette.
If the user is exposed to higher amounts of nicotine compared to cigarettes, then tolerance and dependence to nicotine will occur faster. The user will not be able to stop using the tobacco product without going through some withdrawal reactions. The ability to quit using tobacco becomes quite difficult. Moreover, many smokeless tobacco users are at high risk of becoming cigarette smokers.
Another type of smokeless tobacco is called snus (rhymes with goose), which is the Swedish word for snuff. Snus tobacco is a moist powdered tobacco that is packaged into small pouches, similar to tea bags. These pouches are placed between the user’s lip and gums. The nicotine and other compounds in the tobacco leach out of the packets, and move through the gums into the bloodstream. Snus does not produce extra juices in the mouth, so snus users don’t feel the need to spit.
Figure 3.3 Chemicals in snus are absorbed into the bloodstream. Snus, small packets of tobacco held against the gums, release nicotine, cancer-causing nitrosamines, and other toxic compounds into the bloodstream.
Snus has been sold in Sweden for many years, but it is banned for sale in all other European countries. Recently, many American tobacco companies have designed their own version of the snus and have released this new product into the US market. However, the US snus is quite different from the Swedish form. It contains up to 60 times the levels of cancer-causing nitrosamines (depending on the brand) compared to the Swedish forms.
Some claim that people who use snus don’t get cancer. However, there are no long term studies to actually prove this—large numbers of people have not been using snus for long enough (like 30 years) to detect the cancer.
Nevertheless, recently, even the Swedish form, with lower levels of nitrosamines, has been shown to cause pancreatic cancer.
Another difference from the Swedish snus is that the American snus contains lower amounts of nicotine. As discussed above with reducednicotine cigarettes, the lower the nicotine, the more of the product the user needs to maintain the desired amount of nicotine in her/his brain.
Tobacco LozengesTobacco lozenges are compressed powered tobacco products that are designed to dissolve in the mouth, similar to a lozenge or hard candy. These lozenges have minty flavorings and are about the size of a Tic- Tac™.
Given their size, people may think that the lozenges are not harmful. On the contrary, lozenges are made from the same tobacco found in chewing tobacco and cigarettes, and contain the same carcinogens, such as nitrosamines. As the lozenge is held in the mouth, the nitrosamines and nicotine are absorbed through the cells lining the mouth, into the bloodstream.
Just like with other tobacco products, repeated use can lead to nicotine addiction. Again, since this product is relatively new on the market, it will take a few decades to uncover whether cancer emerges, especially of the mouth.
Addiction and Cancer
All forms of tobacco, whether in a cigarette, pipe, dip, snus, or lozenge, contain the same harmful ingredients. These include nicotine, nitrosamines, arsenic, lead, and other metals.
Makers of different products claim that there are reduced forms of carcinogens such as nitrosamines compared to cigarettes, leading some smokers to believe that switching to a smokeless product may be a better alternative to smoking. But cancer is not a disease that develops based on the amount of the carcinogen; ANY exposure can cause mutations that lead to tumor formation and cancer. So even the presence of low levels of a single carcinogen can increase one’s risk of getting cancer, especially with long-term use.
Additionally, the presence of the nicotine in each of these products provides pleasure to the user, and the user will develop a pattern of use to deliver the amount of nicotine necessary to feel good. So the risk of developing dependence and addiction to the product still exists, in addition to the continued exposure to the toxic chemicals.
Nicotine-delivery products: are they safer?
In addition to smokeless tobacco products, there are several types of nicotine-delivery products on the market. For example, the nicotine patch, gum, and inhaler have been approved by the Food and Drug Administration for use as “nicotine-replacement therapy” by people trying to quit smoking. On average, using a form of nicotine replacement therapy can double one’s chance of giving up tobacco for good. Yet the percentage of tobacco users who actually quit is low, so that leaves millions of users still addicted to nicotine.
Science studies have shown that nicotine-replacement products appear to be a safer alternative to using smokeless tobacco products or modified cigarettes for helping people quit smoking because they don’t contain tobacco.
However, the nicotine-replacement product must be used in a specific way to avoid withdrawal—the user weans off the product over several weeks or months by slowly lowering the dose of nicotine that enters the body. The products are not intended for long-term use.
Figure 3.4 The nicotine patch: a quitting device. The nicotine patch helps users quit when they slowly wean off the nicotine.
Scientists do not yet know whether a person using nicotine (by itself) for many years will develop cancer or heart disease, because people have not been using nicotine-only products for long enough (for example, 30 years) to do the studies. A surprising study released in 2009 indicates that long term use of the nicotine patch can actually cause low levels of nitrosamine carcinogens to be formed from the breakdown of nicotine inside the body.
Thus, we will have to wait at least another decade to know whether using nicotine, which has been shown to cause DNA mutations, prevent the death of cells with damaged DNA, and promote tumor growth in mice, will do the same in humans.
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