The World Health Organisation (WHO), has issued a health alert stating that the consumption of all forms of red meat and processed meat such as pork, beef, hot dog, ham, sausages, corned beef, canned meat and meat-based preparations and sauces among others, carries a high risk of cancer.
The warning which came following an evaluation report by the International Agency for Research on Cancer (IARC), on the carcinogenicity of the consumption of red meat and processed meat, revealed that each 50g portion of processed meat eaten daily increases the risk of colorectal cancer by 18 percent.
A group of 22 scientists from WHO’s International Agency for Research on Cancer in Lyon, France, evaluated more than 800 studies from several continents about meat and cancer. The studies looked at more than a dozen types of cancer in populations with diverse diets over the past 20 years.
Based on that evaluation, the IARC classified processed meat as “carcinogenic to humans,” noting links in particular to colon cancer. It said red meat contains some important nutrients, but still labeled it “probably carcinogenic,” with links to colon, prostate and pancreatic cancers.
The agency said it did not have enough data to define how much processed meat is too dangerous, but said the risk grows with the amount consumed. Analysis of 10 of the studies suggested that a 50-gram portion of processed meat daily — or about 1.75 ounces — increases the risk of colorectal cancer over a lifetime by about 18 percent.
According to the Director of IARC, Dr. Christopher Wild, these findings support current public health recommendations to limit intake of meat.
“Red meat has nutritional values. It is a major source of iron, zinc and vitamin B12. Therefore, these results are important in enabling governments and international regulatory agencies to conduct risk assessments, in order to balance the risks and benefits of eating red meat and processed meat and to provide the best possible dietary recommendations” Wild said
In a statement, the Head of the IARC Monographs Programme, Dr. Kurt Straif said “for an individual, the risk of developing colorectal cancer because of their consumption of processed meat remains small, but this risk increases with the amount of meat consumed.
“In view of the large number of people who consume processed meat, the global impact on cancer incidence is of public health importance.” he said
The cancer agency said a research by the Global Burden of Disease Project suggested that 34,000 cancer deaths per year worldwide are linked to diets heavy in processed meat – compared with 1 million deaths a year linked to smoking, 600,000 a year to alcohol consumption and 200,000 a year to air pollution.
According to WHO an estimated 8.2 million people die each year from cancer, which is 13 percent of all deaths worldwide. There are more than 100 types of cancer, each requiring unique diagnosis and treatment and a 70 percent increase in new cases of cancer is expected over the next two decades.
In reaction to the above, a number of scientists expressed their concerns about the new classification.
One of them is Emeritus Fellow of the Institute of Food Research, Dr Ian Johnson, who said “Although there is epidemiological evidence for a statistically significant association between processed meat consumption and bowel cancer, it is important to emphasize that the size of the effect is relatively small, and the mechanism is poorly defined.”
Also reacting, Emeritus Professor of Neurobiology at Cardiff University, Professor Robert Prickard, stated: “Avoiding red meat in the diet is not a protective strategy against cancer.
“Choosing a meat-free diet is a lifestyle choice – it is not vital for health. For the majority of people who currently eat the recommended dietary levels of red meat, which is 70g per day and wish to continue doing so, moderate amounts of red meat can be enjoyed within a healthy balanced diet.”
In Nigeria, controversy surrounding the link between consumption of red meat and risk of development of cancer is well documented.
A Professor of nutrition, Prof. Ignatius Onimawo, says consumption of the local skewered beef or chicken popularly called Suya, increases the risk of cancer.
Onimawo, a researcher and lecturer at the Ambrose Alli University, Ekpoma, Edo State, said research shows a strong link between consumption of suya and increased risk of cancer.
Years back, the WHO had warned that except there is deliberate effort to imbibe healthier dietary and lifestyle habits over the next decade, cancer and other Non Communicable Diseases, NCDs, would increase by more than 27 percent in developing countries like Nigeria, compared to 17 percent in the developed world.
Explaining how red meat causes cancer, scientist say the sugar molecule Neu5Gc found in red meat such as pork, beef and lamb, is not found naturally in humans, but it is in most other mammals.
When humans eat meat, the molecule enters the tissues. The immune system attacks it, causing inflammation. Over time inflammation has been shown to cause tumors to form. Previous studies have linked red-meat consumption to a number of cancers, especially colorectal, breast, prostate, ovarian and lung cancers
The WHO said its findings were important for helping countries give balanced dietary advice.
Meanwhile, a professor from the Cancer Research UK and the University of Oxford, Prof Tim Key, said: “This decision doesn’t mean you need to stop eating any red and processed meat, but if you eat lots of it you may want to think about cutting down.
“Eating a bacon bap every once in a while isn’t going to do much harm – having a healthy diet is all about moderation. So avoiding red meat in the diet is not a protective strategy against cancer.”
While previous studies have warned that red and processed meats are high in saturated fat and capable of raising the blood cholesterol in the long term, this is the first time, the WHO will be making a pronouncement on the carcinogenicity of processed meat.
Processed meat according to the international body is any meat that has been transformed through salting, curing, fermentation, smoking, or other processes to enhance flavour or improve preservation.