Long-Term Incense Use Linked to Cancer

Regularly inhaling the smoke from incense may increase the risk of most respiratory tract cancers, a new study suggests. The increased risk was observed in both smokers and non-smokers.

Incense has been around for thousands of years and is derived from fragrant plant materials like flowers, essential oils, tree bark, roots and resins. It is commonly used in Asian and Indian cultures for spiritual and medicinal purposes. Many integrative therapies, such as aromatherapy, acupuncture and meditation, also involve the use of incense.

When incense is burned, it has been shown to produce benzene and polyaromatic hydrocarbons, which are some of the compounds in cigarette smoke that have been linked to lung cancer. For this reason, several studies have examined a possible link between incense and lung cancer. However, findings so far have not been conclusive.

In this latest study, more than 61,000 Chinese residents of Singapore who participated in a larger health study were followed from enrollment (between 1993 and 1998) to 2005. At the beginning of the study, none of the subjects had cancer. Participants answered questions about their dietary and lifestyle habits, including the frequency and duration of incense exposure.

By the end of the study, 325 men and women developed cancer of the upper respiratory tract, such as oral, nasal, or throat cancer. Another 821 developed lung cancer. The results, published in the journal Cancer, indicate that heavy exposure to incense was associated with a statistically significant higher risk of cancers of the upper respiratory tract, with the exception of nasopharyngeal cancer, in both smokers and non-smokers. However, incense did not increase the risk of lung cancer.

People who used incense all day or all day and night were 80 percent more likely to develop squamous cell carcinoma of the entire respiratory tract than non-users. This type of cancer causes tumors to develop in the cells that line the internal and external surfaces of the body.

Comments

[SUMA]

I agree with Jimmy that “a carcinogen is a carcinogen.” Ta-Chang Lin states that “PAHs are a group of toxic chemicals, some of which are known to be either mutagenic or carcinogenic.” Jimmy further states that “if benzene and polycyclic aromatic hydrocarbons are found in both cigarette smoke and incense smoke, and these two types of chemicals are known carcinogens, it is not a surprise that both types of smoke may cause cancers, especially if cigarette smoke is known to cause cancer.” Incense smoke has been compared to vehicular exhaust, which is a mixture of chemicals like carbon monoxide.

Some people consider incense to be “indoor air pollution”. When incense is burned, people inhale lung-aggravating tiny particles of ash, as well as carbon monoxide, which can irritate the airways. The fact that it doesn’t contribute to lung cancer but does contribute to other respiratory tract cancers is surprising. I hope future studies are done to try to understand why.

The widespread use of incense in many cultures and healing traditions leads me to believe that people will continue to use incense despite the results of this study. Hopefully, they will follow the recommendations out there that state "if you are going to burn incense, burn it in adequately ventilated areas, preferably outdoors or in rooms with lots of space so the smoke can disperse, and do not buy cheap incense." It is probably worthwhile to try to identify exactly what the incense is made of and where it came from.

[Tamara .S]

Incense, which releases fragrant smoke when burned, was used in ancient Egypt, Greece and Rome, and it is also mentioned in the Old and the New Testaments. It is also found in the major religions of Asia, where many religious ceremonies use this aromatic substance.

Although, the findings pose a significant warning to incense-users worldwide, the researchers of the recent study say further studies are required to see whether different types of incense are associated with different degrees of cancer risk.

Besides initiatives to reduce incense smoke exposure, future studies should be undertaken to identify the least harmful types of incense.

[Becca]

Because burning incense can produce matters known to contain carcinogens, long-term use can increase the risk of developing cancers of the upper respiratory tract. Interestingly enough, studies have not found that long-term incense use increased the incidence of lung cancer.

Long-term incense use is popular in Asia and certain segments of the west. Repeated use for years should be avoided. In one study, burning incense almost doubled the risk of developing upper respiratory tract cancers, including nasal and sinus cancers. Most of us who burn incense on occasion should be fine. It is the long-term use and abuse of anything that will have negative outcomes.

[vicky]

I was curious about the history of incense and how and why they have become so popular. Here is some information I found on Wikipedia:

"The use of incense dates back to biblical times and may have originated in Egypt, where the gums and resins of aromatic trees were imported from the Arabian and Somali coasts to be used in religious ceremonies. It was also used by the Pharaohs, not only to counteract unpleasant odors, but as they believed, also to drive away demons and gratify the presence of gods. The Babylonians used incense extensively while offering prayers to divining oracles. It was imported into Israel in the 5th Century B.C. to be used in religious offerings. It spread from there to Greece, Rome and India, where both Hindus and Buddhists still burn it in their rituals and at festivals. In India some 2000 years B.C., various writings mention "perfumers" and "incense sellers." Evidence suggests oils were used mainly for their aroma."

[Brenda]

I thought it was common knowledge that we should not be inhaling smoke or ashes. A study that shows that inhaling incense smoke over a long period of time resulting in different types of cancers of the respiratory tract is not a surprise to me.

[Anna]

I have never liked incense, and after reading this article, I like it even less! In my opinion, it seems that smoke in general is not good for any living being. I will be sure to pass this information on to anybody I come across whose burning incense. I would imagine that this affects more people in Asian countries that have this sort of tradition. For me, it is no loss.

[Kevin]

Many people think that burning incense is just another way of making their homes smell good. Through this study, people will hopefully realize that they are burning something and actually inhaling smoke. It looks like it will be healthier in the long run to use an air freshener rather than incense.

[jennifer]

This information is no surprise to me either; if you use incense chronically, it cannot be good to breathe in all of those irritants all of the time. I wonder if candles have any of the same effects, if used as often as incense was in this study.

[mai]

Does this effect only occur with incense? What about scented candles? Is there any published research on scented candles that we should be aware of? This information is more like a warning for me since I use scented candles a lot. I hope they (scented candle and incense) do not have the same effects.

[ACB]

I did not know that incense, when burnt, produces the same compounds found in cigarette smoke. It is good that the data do not find incense to increase the risk for lung cancer, as I thought it should not since incense is not inhaled directly or forcefully into the lungs, as one would with cigarettes. However, there is an association or estimated likelihood for upper respiratory tract cancers with the use of incense. I wonder what the incidence is for these types of cancer in Buddhist monks since incense is lit 24/7 in their temples/monasteries.

[PK]

This is great news!! Well for me anyway. As an asthmatic, I have had trouble with incense for years. There’s nothing as wonderful as walking into a “relaxing” environment only to leave seconds later coughing away. Now I have an argument to use that it’s not just my health I am worried about when I ask people not to burn it.

[alocasia]

I passionately collect different types of incense, but after reading this post, I’m a bit scared of developing cancer.

[James]

First of all, what do they consider “heavy” exposure? I’m not too surprised by this finding because I’m assuming inhalation of any smoke can be harmful, especially to the respiratory tract. I am surprised, however, that long-term incense exposure does not contribute to lung cancer as it does to other upper respiratory tract cancers. I also believe this study alone may not be enough to convince certain cultures to stop using it as part of their ritual. This study looked at incense exposure long-term, so I would like to remind people before they begin to panic, that moderation is key with everything!

[Robert Montoya]

This does not surprise me at all. Any inhalation of a burned substance in an excessive amount is bound to have some effect on the respiratory tract. Cancer is becoming an ever increasingly common occurrence and is attributed to more and more substances every day. It makes sense that heavy incense use led to increased upper respiratory tract cancers, but not increased amounts of lung cancer. The exposure to smoke from incense would not be inhaled as deep as smoke from a cigarettes, for example, and thus, would not penetrate deep into lung tissue. Personally, I do burn incense from time to time, and I would like to see a potential correlation to the amount of incense utilized besides the mentioned parameters of burning incense “all day” and “all day and night.”