Share on Facebook Share on Twitter Summary: Cancer was the second biggest cause for deaths globally in 2018 and approximately 9.6 million people died due to this disease i.e. 1 in 6 death globally [1]. Up to half global cancer deaths could be avoided by lifestyle choices such as avoidance of tobacco, dietary changes, and immunizations against cancer causing infections[5]. Advertisement Cancer Quick Facts Genes control our cells and the human body is made up of trillions of such cells. Cancer is the the name given to a collection of diseases caused by changes to our genes and how they control cell function [2]. In business as usual scenario, when cells become old or are damaged, they are replaced by new cells. However, when cancer develops, it disrupts the above process i.e. old cells don’t die when they are supposed to, and new cells develop when they are not supposed to [2]. Furthermore, cancer cells keep dividing abruptly beyond their usual boundaries and can spread quickly to other body parts and may form a lump referred to as a tumour [3,4]. These cells can also invade the immune system and disrupt their normal functions [2]. More than 100 types of cancer have been identified to date. Risk factors include tobacco use, alcohol use, unhealthy diet, physical inactivity, UV radiation (including sun exposure) and cancer-causing infections [5,6]. The below map highlights the regional prevalence of known cancer incidents. Source: IHME, Global Burden of Disease & Our World In Data, Cancer statistics Cancer prevalence by type While lung, prostate, colorectal, stomach and liver cancer are the most common among men, breast, colorectal, lung, cervix and thyroid cancer are the most common among women [5,7]. The World Health Organization estimates that cancer-related deaths would increase by 72% between 2018 – 2040 [8]. Red meat and cancer Several studies have pointed out a strong correlation between consuming red meat (beef, pork, lamb and goat) and colorectal cancer, the second leading type [10]. Source: Cancer Today, WHO – Globocan -2018 Multiple researches on red meat and colorectum cancer claim that almost 70-80 % of cases can be attributed to dietary patterns [12,13]. Processed meat (ham, salami, bacon, sausages) consumption has also been linked to risk of bowel(colorectum) and stomach cancer, which is the third leading cause of cancer-related deaths [10,11]. Furthermore, consumption of foods preserved by salting (i.e. Salted fish, pickles, vegetables) also increases the risk of stomach and nasopharyngeal cancer [10, 11]. Having said that, there is also strong evidence that dairy products consumption can decrease the risk of colorectum cancer, however, it might increase the risk of prostate cancer due to high calcium content [10]. In a nutshell, different studies, including one from WHO claim that by adopting a plant-based diet, cancer-related mortality for certain types can be reduced globally [5,14,15]. Advertisement Causes

Share on Facebook Share on Twitter Causes of Cancer Although there are multiple risk factors for cancer, we will be only focussing on the risks associated with dietary patterns, especially meat, dairy and plant-based products consumption. Advertisement Haem Iron Our body needs iron but not all iron is good. Iron found in food can be classified as Haem and Non-Haem iron. Haem iron is easily absorbed by the body and is usually found in meat, poultry and fish. However, red meat has higher concentrations of haem iron than white meat and is partially responsible for its dark colour [18]. Researchers have found that haem could damage the cells in the body, and as a result, they might divide more often and increase the probability of this disease[17]. Haem is also responsible for stimulating the bacteria in our guts to produce chemicals called N-nitroso compounds, or NOCs. Many of these are known to cause cancer [16,17]. Harmful chemicals in meat Cooking red or processed meat at high temperatures can produce certain chemicals that can increase the risk [10,19]. A chemical called Heterocyclic aromatic amines (HAAs) is formed when meat is grilled or fried at very high temperatures [19,20]. Similarly, Polycyclic aromatic hydrocarbons (PAHs) are formed when meat is smoked or cooked over direct heat, such as barbecuing[19,20]. Both these chemicals are linked to colorectal cancer development in experimental studies based on understanding the co-relation between red meat and cancer risk[10,19,20]. Nitrates – Salts Sodium nitrate and sodium nitrite are the two common preservatives added in processed meat to enhance flavour or protect it from bacteria growing on it. However, these salts can be converted to cancer-causing N-nitroso compounds during the curing or fermentation process [16, 21]. Salting is a traditional method of preserving raw fish as well as some vegetable pickles. There is limited evidence that cantonese-style salted fish increases the risk of nasopharyngeal cancer [21]. Food preserved by salting can also increase the risk of stomach cancer by either damaging the lining of the stomach or by causing inflammation [22]. Stomach cancer is the third leading cause of cancer-related deaths and was responsible for more 782,000 deaths in 2018 [7]. Obesity Obesity is known to increase the risk of 13 types of cancer, according to Cancer Research UK. Fat cells in the body are active and can send out signals to other cells to divide more often, which can lead to this disease. More details on the link between Obesity and Cancer in the Obesity-related article Advertisement Facts Conclusions