Two new global reports have reaffirmed red meat’s place within healthy dietary and lifestyle patterns. Yes, you can eat up to 500g of cooked red meat a week, but barbecue on a solid plate rather than grill.
The World Cancer Research Fund (WCRF)/American Institute for Cancer Research (AICR) reviews and reports on the evidence between lifestyle factors and cancer every 10 years and sets recommendations to reduce cancer risk. Its latest expert report Third Expert Report, Diet, Nutrition, Physical Activity and Cancer: a Global Perspective, updating lifestyle recommendations it made in its 2007 report, was released on 24 May.
In regards to meat consumption, it shows there is strong and convincing evidence that consuming processed meat increases the risk of colorectal cancer and also strong and probable evidence that eating red meat – beef, veal, lamb, pork, mutton, horse or goat – also increases the same risk. This translates to a recommendation of limiting red meat to about three portions a week and consume very little, if any, processed meat. Interestingly, it also notes foods containing haem iron are a limited/suggestive cause of colorectal cancer.
However, Beef + Lamb New Zealand Inc’s head of nutrition Fiona Greig explains the report has also reaffirmed red meat’s place within healthy dietary and lifestyle patterns which recommends up to 500g of cooked red meat, including fresh sausages, a week per person – equivalent to about 700-750g of raw red meat a week.
“It also means processed meat is not off the plate, providing a convenient source of meat’s nutritive attributes, but not to overdo it given its sodium content,” says Greig. “The moderation message rings true yet again. Of note, the New Zealand processed meat industry has made significant advancements reducing 50 tonnes of sodium per annum across bacon, ham and sausages as part of the Heart Foundation reformulation programme,” she notes.
“The advice to the general public remains the same: a balanced diet, which can include red meat, combined with physical activity and a healthy lifestyle, is the best way to reduce cancer risk,” she says.
The report highlights there is no need to stop eating meat, “Meat can be a valuable source of nutrients, in particular protein, iron, zinc and vitamin B12,” it notes.
“In fact, this third report makes an important shift from previous reports to a more holistic focus by noting: ‘It appears increasingly unlikely that specific foods, nutrients or other components of foods are themselves important singular factors in causing or protecting against cancer: rather, different patterns of diet and physical activity combine to create a metabolic state that is more, or less, conducive to cancer’ – what B+LNZ has always emphasised,” says Greig.
Other key points in the report include, the effects of other behaviours, such as people who consume large amounts of red meat tend to consume less vegetables, poultry and fish, and vice versa. It acknowledges that this effect could be in part, due to a low intake of these other foods and that further analysis is required to determine if this is the case.
“In addition, simply removing red meat from an otherwise typical Westernised diet without consideration of the overall balance of the diet, may compromise its nutritional adequacy. In fact it states if unbalanced, vegetarian diets may increase the risk of iron deficiency,” notes Greig, adding that for red meat and processed meat the evidence shows that, in general, the more people consume, the higher the risk.
“High consumers of red and processed meat who reduce their intakes are expected to gain the greatest benefit from following the recommendation.”
Also released at the end of March, was the International Agency for Research on Cancer (IARC)’s monograph 114 on red and processed meat, two years after the IARC Working Group of cancer specialists met in Lyon, France from 6 to 13 October to review data from over 800 studies. The World Health Organisation (WHO) agency’s role is to assess cancer hazards based on reviewing the existing research. Based on its assessment, a substance or activity, which are termed agents, are assessed into a classification group. The meeting resulted in classifications for red meat and processed meats.
“The classification system is not designed to specify the level of risk, so does not take into consideration real life circumstances or any benefits the agent provides, nor makes recommendations, but health agencies consider the IARC evaluations in interventions to reduce cancer risk. Long term, this monograph will influence future policy on where meat fits within dietary recommendations, explains Greig.
Red meat was classified into group 2A – probably carcinogenic to humans – and was among 81 agents classified in that group, including shift work, exposures in hairdressing and hot beverages.
Processed meat was classified in group 1 – carcinogenic to humans – among 120 other agents, including smoking, sunlight and alcohol.
“It is often assumed all of these studies linked meat with cancer. In fact, only a small number of studies were relevant, and a proportion of studies showed no association between meat and cancer,” Greig notes. “Many of the studies report a relative or theoretical risk based on the amount of meat eaten and don’t consider other lifestyle factors that influence cancer risk,” she says.
The monograph acknowledges red meat as a source of high biological value protein and essential micronutrients including vitamins and minerals, noting nutritional value influenced by livestock production systems, such as more omega 3 in grass-fed meat.
In addition, the monograph mentions that cooking effect has an impact on the formation of carcinogenic compounds with high temperature in combination of meat having direct contact with flame and hot surface producing these.
“The advice is when cooking on a barbecue that a solid hot plate rather than a grill is used to avoid direct contact with the flame and charring of meat,” says Greig.
You can read more about the WCRF report at www.dietandcancerreport.org,