Transcript
[Man]: “What are you looking at? Never seen a white guy covered in betel juice before?”
Areca nuts, or betel nuts, are a popular snack commonly eaten by Southeast Asians. They may look like fruit, but they are in fact the seeds of the areca palm. There are many ways to eat them: as seeds, processed and dried for consumption; as betel quid, a combination of the nut and slaked lime wrapped in leaves of the palm, often flavored with a variety of spices; or, as “chewing tobacco”, a combination of betel quid and tobacco leaves (Gupta and Warnakulasuriya 2002). Regardless, the shapes and forms in which areca nuts take all produce the same visually challenging effect: a bloody red mixture of chewed-up seeds in the mouth, which is then spat out by the consumer.
As of 2002, an estimate of 600 million global users were recorded to have consumed areca nuts as a chewing snack, and about 10% of the global population consume the nuts in some form (Gupta and Warnakulasuriya 2002). Despite its obvious popularity, areca nuts are not healthy for long-term or short-term use (Lai and Lee 2006; Liu et al. 2005)—it is not suitable for human use, period. Scientists have long suspected that these palm seeds are cancerous, and through the years they have found mounting evidence to support this claim (IARC 1985, 2004)—even the International Agency for Research on Cancer (IARC) has classified areca nuts as a Group 1 carcinogen (IARC 2021).
The repercussions of consuming this carcinogenic snack can be cosmetically devastating, if not deadly. Regular users often have blackened teeth, bloody gums, and mouth sores, which may develop into some form of oral cancer if left unchecked. Survivors commonly undergo surgery, but this means removing part of their face to prevent the spread of cancerous cells. And the potential negative effects are rather unpleasant—fast heart rates, palpitations, redness in the face, tremors, dizziness, nausea, even psychosis (Chu 2001; ADF 2021). So why do so many people continue to consume areca, if the end results are sickness, mutilation, and death?
The answer is twofold—cultural and chemical. In many countries, areca nuts have been a crucial part of culture and tradition. They are portrayed in art and folklore and incorporated in rituals (Gupta and Warnakulasuriya 2002). The habit of consuming them is instilled in culture. Sharing a betel snack is also considered a form of socially acceptable relaxation, among acquaintances and strangers alike (Strickland 2002)—think cigarettes. Misinformation is yet another problem: some websites promote areca nut as a health benefit (Lybrate 2020), and even scientific papers have concluded that areca has antimicrobial effects (Machova 2021).
On the other hand, the chemical components of this hazardous snack also contribute to its widespread use. Areca nuts are addictive (Chu 2001; Winstock 2002); habitual users experience euphoria and alertness (Chu 2001; ADF 2021) and use it to enhance daily life. The nuts contain alkaloids, a group of naturally occurring compounds that include morphine, nicotine, and caffeine (Kurek 2019). The four alkaloids associated with areca nuts are arecoline, arecaidine, guvacoline, and guvacine (Wang et al. 1997), and various levels of these four chemically related alkaloids have been suspected to be addictive (Jain et al. 2017). Arecoline has even been compared to nicotine, with studies exploring the possibility that it has similar addictive properties (Horenstein et al. 2017).
That is not to say we have no hope in figuring out this problematic phenomenon, however. In a more recent study, scientists Ila Pant, S. Girish Rao, and Paturu Kondaiah explore the biochemical mechanisms behind the cancer-inducing effects of areca nuts in depth. Previous studies have presented evidence that areca nut can induce oral submucous fibrosis, or OSF (Maher et al.1994; Sinor et al.1990), a precancerous disease that has the potential to become malignant (Pindborg et al. 1984). The specific signaling pathways areca nuts activate that causes OSF have even been determined from past experiments (Pant et al. 2015), and in this paper they look closer at this specific pathway.
In the human body, cells signal to each other to send important information to one another and give out instructions to perform their respective roles. This is achieved through the extensive use of proteins. In the paper, the signaling pathway in question is the TGF-beta pathway, which is suspected to be involved with OSF. The researchers knew the TGF-beta protein played a role, but the specific mechanisms of how this pathway worked was still unclear (Pant et al. 2015). As scientists are wont to, they designed an experiment to determine the role of the protein in the signaling it induced. This was achieved through experimenting on four different types of cells and tissue. The first two types, or the control group, were two cell lines, cells grown in petri disks in vitro, or outside the body, using HaCaT and HPL1D human epithelial cells. The other two experimental groups were tissue samples taken from healthy patients and OSF patients, respectively.
The scientists then derived an areca nut extract (ANE) after deshelling and sanitizing areca palm seeds, soaking them in deionized water, and repeatedly straining, chilling, and refining the resulted solution. After a variety of chemicals were used to pretreat their samples, a small amount (5 μg/m) of ANE was added to the control groups at various time intervals (0.5, 1, 2, 4, 6, 12 and 24 hours). They then detected the chemical level and activity level of TGF-beta proteins and other relevant proteins involved in the pathway in each of the four samples using chemical markers and X-ray film. Their skillful manipulation of chemicals showed that in the ANE treated cell lines, OSF was induced, and TGF-beta was present—its chemical and activity levels were high. In the patient tissue samples, high TGF-beta activity and chemical levels were detected in the OSF group. Furthermore, they determined that the high activity level of TGF-beta was dependent on a protein called JNK, and going further up the stream, they discovered that calcium ions, Ca2+, and CAMKII activated JNK. In essence, they were able to gradually figure out the many molecules involved in the TGF-beta pathway, slowly investigating from the end to the beginning.
Figuring out the complicated chemical mechanisms of a specific disease is very satisfying, isn’t it? Of course, that doesn’t mean it will lead to helpful developments of drugs or treatment. Scientific research and drug development is much more complicated than that, and even then many years may wait ahead (FDA 2018). Pant’s paper from 2016 is also rather limited in that it is overly specific—it studies one pathway in the body that is induced by a very specific substance which is responsible for causing a very specific disease. However, these inquiries often bring more knowledge to the table that could be useful in the future. In the case of OSF, isolating the well-studied TGF-beta pathway could shed light on other possible pathways that contribute to OSF, or hint to the cause of similar oral diseases, like squamous cell carcinoma. Furthermore, high levels of TGF-beta mRNA and protein expression correlates with many cancers (Gold 1999), so mapping out the detailed mechanisms in one particular disease could help the scientific community understand other related cancers and conditions, and even give way to new research directions through inspiration.
The endemic of areca nuts itself though, is a social and cultural problem. Science can only help so much in informing the masses of the dangers of consuming areca; in reality, experience and history tell us change often takes time. But it never hurts to learn more about our world, even if it leads to more questions. And with the growth of our knowledge, we might conquer this crimson disease, just like how we eradicated smallpox.
References
Textual:
Alcohol and Drug Foundation. c2021. Melbourne (Australia): ADF; [accessed 2022 Feb 13]. https://adf.org.au/drug-facts/betel-nut/.
Chu, NS. 2001 May. Effects of betel chewing on the central and autonomic nervous systems. Journal of Biomedical Science. [accessed 2022 Feb 13]; 8(3) 229–236. https://web.p.ebscohost.com/ehost/pdfviewer/pdfviewer?vid=1&sid=4f49904d-c11c-4ac0-aba9-7826b370edfa%40redis. doi: 10.1007/BF02256596.
Faouzi M, Neupane RP, Yang J, Williams P, Penner R. 2018 Jan 18. Areca nut extracts mobilize calcium and release pro-inflammatory cytokines from various immune cells. Scientific Reports. [accessed 2022 Jan 26]; 8:1075. https://www.nature.com/articles/s41598-017-18996-2. doi: 10.1038/s41598-017-18996-2.
Gold LI. 1999 Jan 01. The role for transforming growth factor-beta (TGF-beta) in human cancer. Critical Reviews in Oncogenesis. [accessed 2022 Feb 02]; 10(4):303-360. https://europepmc.org/article/med/10654929#impact. PMID: 10654929.
Gupta PC, Warnakulasuriya S. 2002 June 09. Global epidemiology of areca nut usage. Addiction Biology. [accessed 2022 Jan 31]; 7: 77-83. https://web.p.ebscohost.com/ehost/pdfviewer/pdfviewer?vid=1&sid=681df4ac-65b3-42ce-9542-5164ec434d7f%40redis. doi: 10.1080/13556210020091437.
[IARC] International Agency for Research on Cancer. 1985 Sept. IARC Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Humans. Lyon (France). International Agency for Research on Cancer; [accessed 2022 Feb 13]. Volume 37 https://publications.iarc.fr/Book-And-Report-Series/Iarc-Monographs-On-The-Identification-Of-Carcinogenic-Hazards-To-Humans/Tobacco-Habits-Other-Than-Smoking-Betel-Quid-And-Areca-Nut-Chewing-And-Some-Related-Nitrosamines-1985.
[IARC] International Agency for Research on Cancer. 2004. IARC Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Humans. Lyon (France). International Agency for Research on Cancer; [accessed 2022 Feb 13]. Volume 85 https://publications.iarc.fr/Book-And-Report-Series/Iarc-Monographs-On-The-Identification-Of-Carcinogenic-Hazards-To-Humans/Tobacco-Habits-Other-Than-Smoking-Betel-Quid-And-Areca-Nut-Chewing-And-Some-Related-Nitrosamines-1985.
International Agency for Research on Cancer and World Health Organization. c2021. Lyon (France). IARC; [accessed 2022 Feb 13]. https://monographs.iarc.who.int/list-of-classifications/.
Horenstein NA, Quadri M, Stokes C, Shoaib M, Papke RL. 2017 Oct 03. Cracking the Betel Nut: Cholinergic Activity of Areca Alkaloids and Related Compounds. Nicotine & Tobacco Research. [accessed Feb 13]; 21(6): 805–812 https://academic.oup.com/ntr/article/21/6/805/4316088?login=true. doi: 10.1093/ntr/ntx187.
Jain V, Garg A, Parascandola M, Chaturvedi P, Khariwala SS, Stepanov I. 2017 Feb 13. Analysis of Alkaloids in Areca Nut-Containing Products by Liquid Chromatography–Tandem Mass Spectrometry. Journal of Agriculture and Food Chemistry. [accessed 2022 Feb 13]; 65(9): 1977–1983. https://pubs.acs.org/doi/full/10.1021/acs.jafc.6b05140. doi: 10.1021/acs.jafc.6b05140.
Kurek J. 2019 Nov 19. Alkaloids-Their Importance in Nature and for Human Life. InTech Open. [accessed 2022 Jan 31]; https://www.intechopen.com/chapters/66742. doi: 10.5772/intechopen.85400.
Lai KC, Lee TC. 2006 July 25. Genetic damage in cultured human keratinocytes stressed by long-term exposure to areca nut extracts. Fundamental and Molecular Mechanisms of Mutagenesis. [accessed 2022 Feb 13]; 599(1-2): 66-75. https://www.sciencedirect.com/science/article/pii/S0027510706000261. doi: 10.1016/j.mrfmmm.2006.01.005.
Liu SY, Lin MH, Yang SC, Huang GC, Chang L, Chang S, Yen CY, Chiang WF, Kuo YY, Chen LL, Lee CH, Liu YC. 2005 June. Increased expression of matrix metalloproteinase-2 in oral cells after short-term stimulation and long-term usage of areca quid. Journal of the Formosan Medical Association. [accessed 2022 Feb 13]; 104(6): 390-397. https://www.researchgate.net/publication/298546668_Increased_expression_of_matrix_metalloproteinase-2_in_oral_cells_after_short-term_stimulation_and_long-term_usage_of_Areca_Quid. PMID: 16037826.
Lybrate. c2020. India: Lybrate; [accessed 2022 Feb 02]. https://www.lybrate.com/topic/betel-nut-supari-benefits-and-side-effects.
Machová M, Bajer T, Šilha D, Ventura K, Bajerová P. 2021 Dec 07. Volatiles Composition and Antimicrobial Activities of Areca Nut Extracts Obtained by Simultaneous Distillation–Extraction and Headspace Solid-Phase Microextraction. Molecules. [accessed 2022 Feb 13]; 26(24): 7422. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8706666/. doi: 10.3390/molecules26247422.
Maher R, Lee AJ, Warnakulasuriya KAAS, Lewis JA, Johnson NW. 1994 Feb. Role of areca nut in the causation of oral submucous fibrosis: a case-control study in Pakistan. Oral Pathology. [accessed 2022 Feb 02]; 23(2):65-69. https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1600-0714.1994.tb00258.x. doi: 10.1111/j.1600-0714.1994.tb00258.x.
Pant I, Kumar N, Khan I, Rao SG, Kondaiah P. 2015 June 24. Role of Areca Nut Induced TGF-β and Epithelial-Mesenchymal Interaction in the Pathogenesis of Oral Submucous Fibrosis. PLOS ONE. [accessed 2022 Feb 02]; 10(6): e0129252. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0129252. doi: 10.1371/journal.pone.0129252.
Pant I, Rao SG, Kondaiah P. 2016 Oct 06. Role of areca nut induced JNK/ATF2/Jun axis in the activation of TGF-β pathway in precancerous Oral Submucous Fibrosis. Scientific Reports. [accessed 2022 Jan 26]; 6:34314. https://www.nature.com/articles/srep34314. doi: 10.1038/srep34314.
Pindborg JJ, Murti PR, Bhonsle RB, Gupta PC, Daftary DK, Mehta FS. 1984 Jun. Oral submucous fibrosis as a precancerous condition. European Journal of Sciences. [accessed 2022Feb 02]; 92(3): 224-229. https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1600-0722.1984.tb00883.x. doi: 10.1111/j.1600-0722.1984.tb00883.x.
Sinor PN, Gupta PC, Murti PR, Bhonsle RB, Daftary DK, Mehta FS, Pindborg JJ. 1990 Feb. A case-control study of oral submucous fibrosis with special reference to the etiologic role of areca nut. [accessed 2022 Feb 02]; 19(2): 94-98. https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1600-0714.1990.tb00804.x. doi: 10.1111/j.1600-0714.1990.tb00804.x.
Strickland SS. 2002 Jan 01. Anthropological perspectives on use of the areca nut. Addiction Biology. [accessed 2022 Feb 02]; 7(1): 85-97. https://web.p.ebscohost.com/ehost/pdfviewer/pdfviewer?vid=1&sid=e4282608-5bc6-4562-8662-ef1de50db26d%40redis. doi: 10.1080/13556210120091446.
U.S. Food and Drug Administration. c2018. Silver Spring (MD): FDA; [accessed 2022 Feb 02]. https://www.fda.gov/patients/learn-about-drug-and-device-approvals/drug-development-process.
Wang CK, Lee WH, Peng CH. 1997 Apr 16. Contents of Phenolics and Alkaloids in Areca catechu Linn. during Maturation. Journal of Agricultural and Food Chemistry. [accessed 2022 Feb 13]; 45(4): 1185-1188. https://pubs.acs.org/doi/full/10.1021/jf960547q. doi: 10.1021/jf960547q.
Winstock A. 2002 Jan. Areca nut-abuse liability, dependence and public health. Addiction Biology. [accessed 2022 Feb 13]; 7(1): 133-138. https://onlinelibrary.wiley.com/doi/epdf/10.1080/13556210120091509. doi: 10.1080/13556210120091509
Audio and Visual
ANE flow chart [image]. 2022 Feb 20, 1440 × 810 px, color. Daisy Huang.
ANE [image]. 2022 Feb 20, 1440 × 810 px, color. Daisy Huang.
Areca Nut /Betel Nut Processing. 2019 Jan 09, 4:30 mintues. YouTube. S U J A N S H E T T Y. [accessed 2022 Feb 20]. https://www.youtube.com/watch?v=v6azRJOAUyo.
Areca nut for chewing in Changsha [digital photograph]. 2018 Feb 21, 2150 × 1450 px, color. N509FZ. [accessed 2022 Feb 21]. https://commons.wikimedia.org/wiki/File:Areca_nut_for_chewing_in_Changsha_(20180221070959).jpg.
.jpg){kind=link}
Arecanut Tree Climbing Machine | Betel nut / Areca nut Tree Climber Bike. 2020 Nov 01, 5:59 minutes. YouTube. Discover Agriculture. [accessed 2022 Feb 20]. https://www.youtube.com/watch?v=7hr0z3vFJlA.
The Basics of Cell Signaling. 2021 Mar 31, 7:23 minutes. YouTube. Demystifying Medicine. [accessed 2022 Feb 20]. https://www.youtube.com/watch?v=e0R0NIPMHgI.
The Betel Nut Diaries | DONNIE DOES. 2018 May 10, 7:41 minutes. YouTube. Barstool Sports. [accessed 2022 Feb 20]. https://www.youtube.com/watch?v=nlZO2WM40UU.
Betel Nut Documentary – Taiwan Chewing Gum. 2014 Feb 13, 8:51 minutes. YouTube. Steven Domjancic. [accessed 2022 Feb 20]. https://www.youtube.com/watch?v=DyKI6UgI1Jk.
Betel Nut Girls. 2013 Sep 18, 10:06 minutes. YouTube. Rosie Su. [accessed 2022 Feb 20]. https://www.youtube.com/watch?v=JoPg1tap60A.
Burning Cigarette [digital photograph]. 2020 May 05, 960 × 640 px, color. [accessed 2022 Feb 20]. https://www.pikist.com/free-photo-iboan.
“Chew.” The Oral Cancer Documentary. 2017, 14:27 minutes. YouTube. Sasa Productions. [accessed 2022 Feb 20]. https://www.youtube.com/watch?v=ph5bcliqUVI.
Coffee Beans [digital photograph]. 2019 Dec 01, 960 × 640 px, color. [accessed 2022 Feb 20]. https://www.maxpixel.net/Caffeine-Coffee-Beans-Beans-Spoon-Jute-Coffee-4668463.
A day in the life of a Medical Laboratory Technician. 2021 Feb 23, 4:25 minutes. YouTube. careersnz. [accessed 2022 Feb 20]. https://www.youtube.com/watch?v=YDWk-C8nN2Y.
Detecting TGF-beta [image]. 2022 Feb 20, 1440 × 810 px, color. Daisy Huang.
Dr. Paturu Kondaiah [digital photograph]. 112 × 129 px, color. [accessed 2022 Feb 20]. https://iiscprofiles.irins.org/profile/3786.
Figure 1. Chemical structures of the characteristic areca catechu alkaloids arecoline, arecaidine, guvacoline, and guvacine and their reactions with lime [image]. 2016 Dec, 850 × 549 px. Betel Nut Chewing in Iron Age Vietnam? Detection of Areca catechu Alkaloids in Dental Enamel. [accessed 2022 Feb 20]. https://www.researchgate.net/profile/Merja-Neukamm/publication/311783673/figure/fig1/AS:442097930117123@1482415768477/Chemical-structures-of-the-characteristic-areca-catechu-alkaloids-arecoline-arecaidine.png.
Figure 3. Activation of TGF-β pathway by areca nut is dependent on JNK in HaCaT cells [image]. 2016, 1294 × 1342 px. Role of areca nut induced JNK/ATF2/Jun axis in the activation of TGF-β pathway in precancerous Oral Submucous Fibrosis. Scientific Reports. [accessed 2022 Feb 20]. https://www.nature.com/articles/srep34314/figures/3.
Figure 6: Oral submucous fibrosis [digital photograph]. 2016, 753 × 502 px. A digital manual for the early diagnosis of oral neoplasia. International Agency for Research on Cancer. [accessed Feb 20]. https://screening.iarc.fr/atlasoral_detail.php?flag=0&lang=1&Id=A5000003&cat=A5.
Figure 10. Schematic representation of key findings from the study [image]. 2016, 936 × 818 px. Role of areca nut induced JNK/ATF2/Jun axis in the activation of TGF-β pathway in precancerous Oral Submucous Fibrosis. Scientific Reports. [accessed 2022 Feb 20]. https://www.nature.com/articles/srep34314/figures/10.
Frequency Decree. 2022 Feb 15. Cenote. 7:15 minutes. [accessed 2022 Feb 20]. https://freemusicarchive.org/music/Frequency_Decree/cenote/cenote.
HaCaT cells [image]. 2022 Feb 20, 1440 × 810 px, color. Daisy Huang.
HoliznaCC0. 2022 Feb 15. Mundane. 2:38 minutes. [accessed 2022 Feb 21]. https://freemusicarchive.org/music/holiznacc0/lo-fi-and-chill/mundane.
HPL1D cells [image]. 2022 Feb 20, 1440 × 810 px, color. Daisy Huang.
IARC Partial List of Classifications [image]. 2022 Feb 20, 722 × 1024 px, color. Daisy Huang.
Ila Pant and colleague [digital photograph]. 2016 Nov 25, 1200 × 900 px, color. [accessed 2022 Feb 20]. https://bangaloremirror.indiatimes.com/thumb/msid-55607653,width-1200,height-900,resizemode-4/.jpg.
In Myanmar, Betel Quid Chewing Remains Popular Despite Risks. 2020 Feb 03, 2:30 minutes. YouTube. VOA News. [accessed 2022 Feb 20]. https://www.youtube.com/watch?v=JA0BLfOq914.
Man with missing jaw [digital photograph]. 2007 Jul 11, 500 × 333 px, color. Pichi Chuang.
[accessed 2022 Feb 20]. https://tnimage.s3.hicloud.net.tw/photos/shares/parchemm/20070711/885659.jpg.
Man with opening on left cheek [digital photograph]. 976 × 549 px, color. [accessed 2022 Feb 20]. https://www.bbc.com/news/health-31921207.
Morphine vial [digital photograph]. 2009 Dec 04, 3072 × 2304 px, color. Vaprotan. [accessed 2022 Feb 20]. https://commons.wikimedia.org/wiki/File:Morphine_vial.JPG.
Myanmar Costly Chewing [digital photograph]. 2016 Jun 08, 4497 × 2790 px, color. AP. Gemunu Amarasinghe. [accessed 2022 Feb 14]. http://www.apimages.com/metadata/Index/Myanmar-Costly-Chewing/d726986a4cdb4d1a8c95626081829bf0/1/0.
Patient after oral cancer surgery, front [digital photograph]. 768 × 511 px, color. [accessed 2022 Feb 21]. https://phys.org/news/2017-10-taiwan-betel-nut-addiction.html#:~:text=For%20years%20Huang%20Sheng%2Dyi,trees%20on%20his%20mountainous%20farm.
Patient doing rehabilitation exercises after oral cancer surgery [digital photograph]. 768 × 512 px, color. [accessed 2022 Feb 21]. https://phys.org/news/2017-10-taiwan-betel-nut-addiction.html#:~:text=For%20years%20Huang%20Sheng%2Dyi,trees%20on%20his%20mountainous%20farm.
Patient tissue [image]. 2022 Feb 20, 1440 × 810 px, color. Daisy Huang.
Red stained lips and teeth from constant chewing of betel nut–a natural stimulant [digital photograph]. 2009 Jul. 30, 1000 × 750 px, color. Lee V. de Zeeuw. [accessed 2022 Feb 20]. https://flickr.com/photos/luc-de-zeeuw/5408244303/in/photolist-9eUEBr-9eUFp4/.
Researcher finds key clues about “betel nut” addiction that plagues millions worldwide. 2015 Oct 15, 2:40 minutes. YouTube. UF Health. [accessed 2022 Feb 20]. https://www.youtube.com/watch?v=QmbrbQk4KeY.
Screenshot of Journal, Antimicrobial [image]. 2022 Feb 20, 1084 × 1530 px, color. Daisy Huang.
The Side Effects of Vaccines – How High is the Risk?. 2019 May 12, 10:55 minutes. YouTube. Kurzgesagt – In a Nutshell. [accessed 2022 Feb 20]. https://www.youtube.com/watch?v=zBkVCpbNnkU.
Thawing Cells: Cell Culture Basics. 2018 May 21, 3:57 minutes. YouTube. Thermo Fisher Scientific. [accessed 2022 Feb 20] https://www.youtube.com/watch?v=4HxqQOHifkU.
Tombstones in Cemetery [digital photograph]. 2017 Apr 23, 960 × 640 px, black and white. [accessed 2022 Feb 20]. https://www.maxpixel.net/Tombstone-Cemetery-Old-Dead-Old-Grave-Stones-2254390.
Treatments [image]. 2022 Feb 20, 1440 × 810 px, color. Daisy Huang.
Understanding Psychosis. 2020 Dec 15, 6:41 minutes. YouTube. NYC Mayor’s Office of Community Mental Health. [accessed 2022 Feb 20]. https://www.youtube.com/watch?v=GydF1N2Jhtw.
University of Guam Cancer Research Center – Researching the Effects of the Areca (Betel) Nut. 2018 Nov 31, 4:56 minutes. YouTube. UOG Tritons. [accessed 2022 Feb 20]. https://www.youtube.com/watch?v=4mJYQN5Z-s0.
What is cancer? What causes cancer and how is it treated? *UPDATE*. 2017 Feb 23, 6:35 minutes. YouTube. Cancer Treatment Centers of America – CTCA. [accessed 2022 Feb 20]. https://www.youtube.com/watch?v=_N1Sk3aiSCE.
Why do we sweat? – John Murnan. 2018 May 15, 4:47 minutes. YouTube. TED-Ed. [accesses 2022 Feb 20]. https://www.youtube.com/watch?v=fctH_1NuqCQ.
The World’s Most Addictive Drug? (Betel Nut). 2018 May 15, 4:38 minutes. YouTube. Drew Binsky. [accessed 2022 Feb 20]. https://www.youtube.com/watch?v=v5sXqU0sga0.
World’s most addictive drug?! (and it’s also a food!). 2021 Jul 31, 4:09 minutes. YouTube. Project Nightfall. [accessed Feb 20]. https://www.youtube.com/watch?v=n7Gf3QMlHEo.
Featured Image
Red stained lips and teeth from constant chewing of betel nut–a natural stimulant [photograph]. 2009 Jul. 30, 1000 × 750 px, color. Lee V. de Zeeuw. [accessed 2022 Feb 20]. https://flickr.com/photos/luc-de-zeeuw/5408244303/in/photolist-9eUEBr-9eUFp4/.