Today the BBC carried yet another warning about the health dangers of red meat, under the heading, ‘Red meat cancer risk to be revealed by World Health Organization’. But read the article below it and it is almost entirely about the danger of eating too much processed meat. It says that the WHO is yet again looking into the possibility of links between bowel cancer and eating red and processed meats, not that it is going to reveal that red meat does carry a cancer risk.
The article then states, ‘UK advice says eating a lot of red and processed meat probably increases the risk of bowel cancer’, without quoting any authority or scientific evidence for the statement, and immediately contradicts it in the next sentence, ‘But the Department of Health says red meat can be part of a healthy diet.’ All the rest of the article is not about red meat, as the headline suggests, but processed meat.
Processed meat is beef, pork and chicken that has been treated in some way to preserve it, most commonly by adding sodium nitrite, which is what gives ham, bacon, frankfurters, packaged sausages and similar products their characteristic pink colour. Sodium nitrite is very effective in preventing the growth of clostridium botulinum during the curing process.
Within an hour the headline was changed to, ‘Processed meats do cause cancer – WHO’. Someone with influence must have complained.
These are the facts.
(1) Red meat eaten in normal quantities is not a risk factor for cancer.
In 2011 the World Cancer Research Fund in collaboration with the American Institute for Cancer Research published an extremely thorough review of all the available evidence on the subject in a report entitled, Continuous Update Project Report Summary: The Association between Food, Nutrition and Physical Activity and the Risk of Colectoral Cancer. This included the statements, ‘An abstract from pooling 14 prospective studies and 7743 colectoral cancer cases did not support a positive association between red meat intake and colectoral cancer risk,’ and ‘The U.K. Dietary Cohort Consortium has recently reported no evidence of association between red meat consumption and colectoral cancer risk in a pooled analysis of food diary data from seven prospective studies.’
Only one of the many studies reviewed in the report found some association between eating unprocessed red meat and bowel cancer, and this related to some American men who regularly ate over half a kilogram of red meat a day and very few vegetables. On even a half-healthy normal diet, there is no evidence that eating red meat is even associated with bowel cancer, let alone that it causes it.
(2) In some circumstances processed meats may carry some risk of cancer.
When sodium nitrite is heated, chemicals known as nitrosamines are released, and these are considered to promote the growth of cancers, especially cancers of the stomach and oesophagus. Frying bacon until it is crisp definitely produces such chemicals, whereas rashers microwaved for only 45-seconds produced no detectable nistrosamines. Therefore when frying or barbecuing packaged bacon, sausages or other meats preserved with sodium nitrite, care should he taken not to over-cook them, and they should never be burned.
Even without cooking such meats, they will produce some nitrosamines during digestion. Green vegetables naturally contain nitrates, which are converted by bacteria in our mouths into nitrites such as sodium nitrite, releasing nitric oxide which helps to keep our blood pressure down. The acid in our stomach converts the resulting sodium nitrite into nitrosamines, but because vegetables also contain lots of antioxidants these counteract their nasty effects. But regularly eating significant quantities of meats processed with sodium nitrite without taking in sufficient compensating quantities of antioxidants may well induce cancers of one form or another.
Beef and other red meats from animals grazing on grass fertilized with nitrates also contain low levels of nitrates, which probably explains why large red meat eaters who don’t eat many vegetable do run a slightly increased risk of bowel cancer. Organically raised beef would probably be risk-free.
(3) Frying bacon and sausages in temperate oils may induce cancer.
Cooking oils made from temperate oil-bearing seeds such as sunflower, rapeseed, maize and soya beans oxidize on heating, and oxidized oils produce tissue-damaging free radicals when they get into our bodies.
In 2001 a review of studies made during the previous 20 years in the U.K., the U.S.A. and Spain concluded that the prolonged consumption of burnt oils was likely to lead to ‘atherosclerosis, the forerunner to cardiovascular disease; inflammatory joint disease, including rheumatoid arthritis; pathogenic conditions of the digestive tract; mutagenicity and genotoxicity, properties that often signal carcinogenesis; and teratogenicity, the property of chemicals that leads to the development of birth defects’.
So use lard, dripping or tropical seed oils to fry your processed meats, or better still buy fresh bacon or sausages instead of processed ones.
That brings me at last to my opening question, ‘Why are the media correspondents so keen to stop us eating red meat?’ If they are vegans or vegetarians then they will obviously latch on to anything that supports their belief that eating meat is unhealthy, unethical or destructive of the environment. But for the majority of correspondents I think their frequent media attacks on red meat are for two reasons.
The first reason is that health correspondents are rarely scientists themselves, and their main concern is to produce an interesting article with an eye-catching headline. ‘Red meat cancer risk to be revealed by World Health Organization’ makes a far more arresting headline than ‘Processed meat cancer risk to be investigated by World Health Organization’, which is what the heading should have been.
The second reason is that among the general public, including health correspondents, there is a bias induced against anything natural and in favour of manufactured foods of all kinds. This bias is produced by the advertisements of food manufacturers, whose huge profits provide the money to pay for them. On the other hand, farmers who produce natural foods such as milk and meat are paid hardly enough to make a living and therefore have no money left to produce expensive television advertisements that could tell us truthfully that ‘butter is naturally heart-healthy’, that ‘meat is the best source of protein, B vitamins, iron and zinc’, and that ‘red meat contains higher levels of haemoglobin and myoglobin, the iron and oxygen-binding proteins you need in your blood and muscles’.
What infuriates me is that these periodically recurring tirades against red meat put farmers out of business for no reason other than the desire to produce an eye-catching headline and a scare-mongering story.
 Larsson S C et al. Processed meat consumption, dietary nitrosamines and stomach cancer risk in a cohort of Swedish women. International Journal of Cancer, August 2006; 119(4):915-9.
 Nitrosamine. Wikipedia, August 2014.
 Miller B J. et al. Formation of N-nitrosamines in microwaved versus skillet-fried bacon containing nitrite. Food and Chemical Toxicology, May 1989; 27(5):295-9.
 Grottveld M et al. Health effects of oxidized heated oils. Foodservice Research International, Volume 13, Issue 1: 41–55. 2001.