Snus and Cancer: Is There a Link?


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Snus is a moist, smokeless, finely ground tobacco product marketed as a less harmful alternative to smoking. It’s sold loose and in packets (like very small teabags).

Snus is placed between the gum and the top lip and sucked for about 30 minutes. It’s less finely ground than snuff, and it isn’t placed in the nose. Unlike chewing tobacco, it doesn’t usually involve spitting.

It’s been used for 200 years in Sweden, and for the last several years has also been manufactured in the United States. Similar products to snus are traditionally used around the world, but they vary greatly in nicotine and other chemical content.

Fast facts

  • An estimated 10 to 25 percent of the world population uses smokeless tobacco, including snus.
  • The U.S. Food and Drug Administration (FDA) reported that in 2014, an estimated 1.9 percent (280,000) of high school students and 0.5 percent (50,000) of middle school students were current users of snus.
  • The market specifically for snus is expected to grow by 4.2 percent by 2023.
  • In 2014, snus products were 1.7 percent of the U.S. smokeless tobacco market.

Beneficial or harmful?

The use of snus is controversial. The European Union has banned its sale (except for in Sweden) because of the known addictive and harmful effects of nicotine. U.S. health agencies advise against its use.

There’s a concern that snus can be a “gateway” to cigarette smoking, by hooking young people on nicotine.

But advocates of snus claim that snus is less harmful than inhaling nicotine, even though it’s addictive. The snus tobacco isn’t burned, and no smoke is inhaled. So some of the worst effects of smoking aren’t present.

Plus, snus advocates say, it helps people stop smoking. They point to the public health benefits of snus use in Sweden.

Specifically, the smoking rate dropped dramatically in Sweden as more men switched to snus use. According to a 2003 review in the BMJ journal Tobacco Control, 40 percent of males smoked daily in 1976, compared with 15 percent in 2002.

At the same time, the researchers found that there have been reductions in lung cancer, cardiovascular disease, and deaths from other causes in Sweden.

So, does snus cause cancer?

Whether snus causes cancer is a complex question to sort out scientifically. Study results are bewilderingly diverse. Some studies find a specific cancer risk connected to snus use, and other studies find the opposite.

Sometimes there are differences in the population groups or the timespans studied.

Some research studies lump all smokeless tobacco products together. Others are limited to snus use in Swedish populations.

Sometimes, other factors like alcohol use or body weight aren’t included.

What’s not in dispute is the link between inhaling the smoke from nicotine products and disease.

Here, we’ll look at some of the studies concerning cancer and snus.

Pancreatic cancer and snus

Smoking is known to be a high risk factor for pancreatic cancer. A meta-analysis of 82 different studies found that the increased risk of pancreatic cancer for current smokers was 74 percent. The increased risk for former smokers was 20 percent.

Does the risk remain the same with smokeless tobacco? The results aren’t clear-cut. Two studies that included snus specifically found a moderate risk increase. Two other studies found no association.

A 2007 study of Swedish construction workers who used snus and who hadn’t previously smoked found an increased risk of pancreatic cancer. The study concluded that use of Swedish snus should considered a possible risk factor for pancreatic cancer.

The most recent and largest study, reported in 2017, involved a large sample of 424,152 males in Sweden. This included nonusers and users of snus. This study concluded that the data didn’t support any relationship between snus use and risk of pancreatic cancer in men.

The 2017 study authors noted that their findings may be related to the lower nitrosamine levels in Swedish snus than in tobacco smoke. They also suggested that the increased risk of pancreatic cancer in tobacco smokers is related to the carcinogens involved with combustion.

Oral cancers and snus

Tobacco smoking is one of the strongest risk factors for oral cancers.

Evidence for snus leading to oral cancers is mixed. A 2008 study concluded that the risk of oral cancer for smokeless tobacco users is likely less than that of smokers, but more than that of people who don’t use tobacco.

A 2013 study, which included snus products from different countries, made a stronger conclusion: that there is a strong link between smokeless tobacco use and cancers of the cheek and gums. The study noted that the previous data on smokeless tobacco and oral cancers was sparse.

A 2007 study of 125,576 Swedish construction workers who used snus but were previously nonsmokers concluded that there was no increased risk of oral cancers in snus users. (Note that this is the same study that found an increased risk of pancreatic cancer in the same population.)

Another Swedish study differed. This 2012 case report of 16 Swedish men with oral squamous cell cancers concluded that Swedish snuff might not be a harmless alternative to smoking. These men had used snus prior to cancer diagnosis for a mean of 42.9 years. The cancers were in the sites where they had placed snus.

A similar warning came from a long-term study of 9,976 Swedish snus-using men. This study, reported in 2008, advised that the risk of oral cancer for snus users couldn’t be ruled out. It found a high incidence of oral, pharyngeal, and overall total smoking-related cancer in the snus users studied.

An independent report was commissioned by leading Swedish snus producer Swedish Match. It comments on the characteristic type of mouth lesion that snus users may get. These are reversible after snus use is stopped, the report notes. The report also states that there isn’t any clinical evidence suggesting the lesions turn into cancer.

Gastric cancer and snus

Smoking has a high risk of stomach cancer, also known as gastric cancer. The rate of stomach cancer among smokers is almost double that of nonsmokers.

What about snus users? Again, the evidence is mixed.

A 1999 study of Swedish workers found that smokeless tobacco wasn’t associated with an increased risk of any type of gastric cancer. A 2000 study in Sweden came to the same conclusion.

A 2008 study reviewed the health records of 336,381 male Swedish construction workers from 1971 to 1993, with follow-up records through 2004. This study found “excess risks” for stomach cancer among snus users who had never smoked.

A 2015 study of smokeless tobacco users in India found what they called “a small but significant association” of smokeless tobacco and stomach cancer. The smokeless tobacco studied may be different from snus, however.

Skin cancer and snus

Smoking doubles your risk of skin cancer, specifically squamous cell carcinoma.

But the research on snus and skin cancer is too limited to reach a conclusion.

A 2005 nationwide study in Sweden found no association of an increased risk of smoking to skin squamous cell carcinoma. It also noted that snus users had a decreased risk of developing squamous cell carcinoma.

Country of manufacture and risk

The country of manufacture makes a difference in the composition of the snus product. This may affect cancer risk.

Swedish snus vs. American snus

The snus-type products produced in the United States are different from Swedish-produced snus.

American snus products contain more nicotine than Swedish snus. But the nicotine’s ability to be absorbed by your body is lower in the American products. Two main factors control how much nicotine you get from snus:

  • how alkaline (opposite of acidic) the snus is as measured by pH
  • the moisture content

A higher pH (more alkali) means the nicotine in the snus can be absorbed faster into your bloodstream. Swedish snus has a median pH of 8.7, compared to 6.5 for American snus brands.

Swedish snus also contains significantly higher moisture than American brands. Higher moisture content increases the rate that nicotine can be absorbed into your bloodstream.

The higher rate of nicotine delivery means that users of Swedish snus are less likely to turn to cigarettes for their nicotine source. A survey of 1,000 ex-smokers in Sweden found that 29 percent had switched to snus to quit smoking.

Another advantage of Swedish snus is the lower levels of nitrites (TSNAs) compared to American brands. The tobacco in Swedish snus is air- or sun-dried, which reduces the nitrite level compared to the tobacco in American snus, which is normally fire-cured.

The higher pH and moisture content, as well as the lower nitrite levels, allow Swedish snus to deliver more nicotine at less risk of adverse effects than the American brands.

Swedish snus users develop a dependency on the nicotine, but the risk of cancer and heart disease is considerably lessened compared to smoking.

Other risks and side effects of snus

There are other health effects of snus. Again. the results of studies are inconsistent. Here are a few examples.

Cardiovascular disease

A 2003 review of public health effects of snus in Sweden reported that snus users may have a small cardiovascular risk compared to nonsmokers.

It also reported that all the large studies on the subject in Sweden are in agreement that smokeless tobacco has a much lower risk for adverse cardiovascular effects than smoking does.

Diabetes

A 2004 study in northern Sweden found that snus users didn’t have a significantly increased risk of diabetes.

The opposite conclusion was reached by a 2012 study of middle-aged Swedish men. This study concluded that high consumption of snus predicts a risk of developing type 2 diabetes.

Metabolic syndrome

Metabolic syndrome is a cluster of risk factors that increase your likelihood of developing heart disease, diabetes, or stroke.

A 2017 study that looked at Swedish snus users over time at ages 21, 30, and 43 found no association between snus use and risk of metabolic syndrome. The researchers suggested that it would be useful to look at the risk for people who used snus and smoked cigarettes.

In 2010, the American Heart Association issued a policy statement based on data from two Swedish studies. These studies concluded that heavy use of snus appears to increase the odds of developing metabolic syndrome and type 2 diabetes.

Asthma

A large Swedish study of 16- to 75-year-olds suggested that snus use was associated with a higher prevalence of asthma. Former snus users didn’t have this association. But snoring was associated with both current and former users.

High blood pressure

A recent small study looked at the effect of snus on blood pressure, heart rate, and arterial stiffness. It suggested that snus use increased blood pressure and heart rate in women, but not in men.

The takeaway

Does snus increase your risk of cancer? Looking at the variety of evidence is a little like looking at a glass of water that is either half-full or half-empty. You can minimize or maximize the scientific findings of any particular study.

The producers of snus in Sweden, chiefly Swedish Match, consider any risks shown to be minimal. But health agencies concerned with nicotine addiction and recruitment of youth to nicotine see the dangers.

The bottom line: Snus use is addictive, but it probably has fewer risks than cigarette smoking.


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