Meat eaters around the world were in for a shock this week after the World Health Organisation (WHO) revealed that processed meat products cause cancer.
Processed meat refers to any meat that is salted, cured or smoked. It includes ham, bacon, sausages and hot dogs.
These food items now join asbestos, arsenic and tobacco in the long list of Group 1 carcinogens, which are known to cause cancer.
The revelation was contained in a report by the WHO's International Agency for Research on Cancer (IARC).
Eating just 50 gm of processed meat daily (or one hot dog) increases the risk of colorectal cancer (or bowel cancer) by 18%.
It is believed that substances added during processing, including preservatives like nitrates and nitrites, cause cancer.
Red meat is also risky but less so. It is classified as a Group 2A carcinogen, which consists of things that are 'probably carcinogenic to humans'.
However, not all substances that cause cancer are equally dangerous.
Heavy smoking, for example, brings a much greater risk of cancer than eating processed meat.
But being vegetarian is the safest option.
Here's the full list of 116 Group 1 carcinogens that cause cancer in humans according to the IARC:
1. Tobacco smoking
2. Sunlamps and sunbeds
3. Aluminium production
4. Arsenic in drinking water
5. Auramine production
6. Boot and shoe manufacture and repair
7. Chimney sweeping
8. Coal gasification
9. Coal tar distillation
10. Coke (fuel) production
11. Furniture and cabinet making
12. Haematite mining (underground) with exposure to radon
13. Secondhand smoke
14. Iron and steel founding
15. Isopropanol manufacture (strong-acid process)
16. Magenta dye manufacturing
17. Occupational exposure as a painter
18. Paving and roofing with coal-tar pitch
19. Rubber industry
20. Occupational exposure of strong inorganic acid mists containing sulphuric acid
21. Naturally occurring mixtures of aflatoxins (produced by funghi)
22. Alcoholic beverages
23. Areca nut - often chewed with betel leaf
24. Betel quid without tobacco
25. Betel quid with tobacco
26. Coal tar pitches
27. Coal tars
28. Indoor emissions from household combustion of coal
29. Diesel exhaust
30. Mineral oils, untreated and mildly treated
31. Phenacetin, a pain and fever reducing drug
32. Plants containing aristolochic acid (used in Chinese herbal medicine)
33. Polychlorinated biphenyls (PCBs) - widely used in electrical equipment in the past, banned in many countries in the 1970s
34. Chinese-style salted fish
35. Shale oils
36. Soots
37. Smokeless tobacco products
38. Wood dust
39. Processed meat
40. Acetaldehyde
41. 4-Aminobiphenyl
42. Aristolochic acids and plants containing them
43. Asbestos
44. Arsenic and arsenic compounds
45. Azathioprine
46. Benzene
47. Benzidine
48. Benzo[a]pyrene
49. Beryllium and beryllium compounds
50. Chlornapazine (N,N-Bis(2-chloroethyl)-2-naphthylamine)
51. Bis(chloromethyl)ether
52. Chloromethyl methyl ether
53. 1,3-Butadiene
54. 1,4-Butanediol dimethanesulfonate (Busulphan, Myleran)
55. Cadmium and cadmium compounds
56. Chlorambucil
57. Methyl-CCNU (1-(2-Chloroethyl)-3-(4-methylcyclohexyl)-1-nitrosourea; Semustine)
58. Chromium(VI) compounds
59. Ciclosporin
60. Contraceptives, hormonal, combined forms (those containing both oestrogen and a progestogen)
61. Contraceptives, oral, sequential forms of hormonal contraception (a period of oestrogen-only followed by a period of both oestrogen and a progestogen)
62. Cyclophosphamide
63. Diethylstilboestrol
64. Dyes metabolized to benzidine
65. Epstein-Barr virus
66. Oestrogens, nonsteroidal
67. Oestrogens, steroidal
68. Oestrogen therapy, postmenopausal
69. Ethanol in alcoholic beverages
70. Erionite
71. Ethylene oxide
72. Etoposide alone and in combination with cisplatin and bleomycin
73. Formaldehyde
74. Gallium arsenide
75. Helicobacter pylori (infection with)
76. Hepatitis B virus (chronic infection with)
77. Hepatitis C virus (chronic infection with)
78. Herbal remedies containing plant species of the genus Aristolochia
79. Human immunodeficiency virus type 1 (infection with)
80. Human papillomavirus type 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59 and 66
81. Human T-cell lymphotropic virus type-I
82. Melphalan
83. Methoxsalen (8-Methoxypsoralen) plus ultraviolet A-radiation
84. 4,4'-methylene-bis(2-chloroaniline) (MOCA)
85. MOPP and other combined chemotherapy including alkylating agents
86. Mustard gas (sulphur mustard)
87. 2-Naphthylamine
88. Neutron radiation
89. Nickel compounds
90. 4-(N-Nitrosomethylamino)-1-(3-pyridyl)-1-butanone (NNK)
91. N-Nitrosonornicotine (NNN)
92. Opisthorchis viverrini (infection with)
93. Outdoor air pollution
94. Particulate matter in outdoor air pollution
95. Phosphorus-32, as phosphate
96. Plutonium-239 and its decay products (may contain plutonium-240 and other isotopes), as aerosols
97. Radioiodines, short-lived isotopes, including iodine-131, from atomic reactor accidents and nuclear weapons detonation (exposure during childhood)
98. Radionuclides, α-particle-emitting, internally deposited
99. Radionuclides, β-particle-emitting, internally deposited
100. Radium-224 and its decay products
101. Radium-226 and its decay products
102. Radium-228 and its decay products
103. Radon-222 and its decay products
104. Schistosoma haematobium (infection with)
105. Silica, crystalline (inhaled in the form of quartz or cristobalite from occupational sources)
106. Solar radiation
107. Talc containing asbestiform fibres
108. Tamoxifen
109. 2,3,7,8-tetrachlorodibenzo-para-dioxin
110. Thiotepa (1,1',1'-phosphinothioylidynetrisaziridine)
111. Thorium-232 and its decay products, administered intravenously as a colloidal dispersion of thorium-232 dioxide
112. Treosulfan
113. Ortho-toluidine
114. Vinyl chloride
115. Ultraviolet radiation
116. X-radiation and gamma radiation
