Red meat in your diet: the facts
We’ve recently received an interesting letter from a ‘BBY magazine’ reader commenting on Dr Rosemary Stanton’s March 2012 issue article about meat in your diet (‘Meaty Bites’). Our reader asked for proof, and so we have posted both the reader’s letter, and Rosemary’s reply, here on the website, as the list of references is just too big to include in the magazine. Please feel free to look up these journals Rosemary mentions and decide for yourself (your local library can help you access the journal articles cited, if you need assistance).
We stand by every word Dr Rosemary Stanton writes on nutrition in our magazine. We value all our magazine’s contributors, as each is a leading expert in his or her field, and there’s no better respected name in nutrition in Australia than Dr Rosemary Stanton. Her opinions are based on the latest scientific research, and in her reply below I think you’ll agree that Rosemary does have solid scientific proof to back up every word she says on the topic of meat in your diet. Don Burke
Reader’s letter
Dear people at BBY: I have some questions regarding Rosemary Stanton’s recent article about red meat (in the March 2012 issue of ‘Burke’s Backyard’ magazine, pages 88-89). Where have these studies been carried out, under what circumstances? It is just not good enough to say many studies have been carried out – can they be proved?
June, via email
Dr Rosemary Stanton’s reply
In response to your query about studies backing the statements made in the article ‘meaty bites’ in the March 2012 issue of ‘Burke’s Backyard’ magazine, I have listed (below) some of the many references that underpinned my statement that while there is no evidence that small quantities of red meat are harmful to health, large quantities are linked to health problems.
A review of literally hundreds of studies led the World Cancer Research Fund and the American Institute of Cancer Research (whose panels of highly distinguished world experts has carefully sifted through all the evidence from a large number of cohort studies) to produce an extensive review titled ‘Food, Nutrition, Physical Activity and the Prevention of Cancer: a Global Perspective’. You can download this (it’s free) at www.dietandcancerreport.org
Also, a brief summary of their report is available at http://www.wcrf.org/cancer_research/expert_report/recommendations.php and regular updates to the evidence are also listed at Continuous Update Project.
Some other easily accessed papers include:
‘Red and processed meat and colorectal cancer incidence: meta-analysis of prospective studies’. Chan DS, Lau R, Aune D, Vieira R, Greenwood DC, Kampman E & Norat T. PLoS ONE. 2011; 6: e20456. After reviewing another 10 recent studies and citing 72 references, this paper concludes: “High intake of red and processed meat is associated with significant increased risk of colorectal, colon and rectal cancers.”
Cross AJ et al. ‘A large prospective study of meat consumption and colorectal cancer risk: an investigation of potential mechanisms underlying this association.’ Cancer Res. 2010 Mar 15;70 (6):2406-1. It says: “In conclusion, we found a positive association for red and processed meat intake and colorectal cancer; heme iron, nitrate/nitrite, and heterocyclic amines from meat may explain these associations.”
Lee DH, Anderson KE, Harnack LJ, Folsom AR, Jacobs DR Jr. ‘Heme iron, zinc, alcohol consumption, and colon cancer: Iowa Women’s Health Study.’ J Natl Cancer Inst 2004;96:403-7.
Larsson SC, Rafter J, Holmberg L, Bergkvist L, Wolk A. ‘Red meat consumption and risk of cancers of the proximal colon, distal colon and rectum: The Swedish Mammography Cohort.’ Int J Cancer 2005;113:829–34.
English DR et al. ‘Red meat, chicken, and fish consumption and risk of colorectal cancer.’ Cancer Epidemiol Biomarkers Prev September 2004 13; 1509. This Australian study concluded: “Consumption of fresh red meat and processed meat seemed to be associated with an increased risk of rectal cancer. Consumption of chicken and fish did not increase risk.”
For heart disease, a particularly powerful paper (because it looked at over 500,000 people and followed them until their deaths is Sinha R, Cross AJ, Graubard BI, Leitzmann MF, Schatzkin A. ‘Meat intake and mortality: a prospective study of over half a million people.’ Arch Intern Med. 2009 Mar 23;169(6):562-71. The paper concluded: “Red and processed meat intakes were associated with modest increases in total mortality, cancer mortality, and cardiovascular disease mortality.”
Haem iron
Among the literally hundreds of papers listed on the Pub Med listings of peer-reviewed articles (which you can access via http://www.ncbi.nlm.nih.gov/pubmed), some specifically related to haem iron are listed below. The following references show positive results for haem iron and some specific cancers. There are also a few reports that show no association of haem iron with cancers of the breast and prostate and since some work is still underway in many laboratories, I was careful to note that the risk did not appear at low meat intakes.
Balder HF, Vogel J, Jansen MC, Weijenberg MP, van den Brandt PA, et al. ‘Heme and chlorophyll intake and risk of colorectal cancer in the Netherlands cohort study.’ Cancer Epidemiol Biomarkers Prev. 2006;15:717–725.
Ward MH, Cross AJ, Abnet CC, Sinha R, Markin RS, Weisenburger DD. ‘Heme iron from meat and risk of adenocarcinoma of the esophagus and stomach.’ Eur J Cancer Prev. 2012;21(2):134-8.
Baradat M, Jouanin I, Dalleau S, Taché S, Gieules M, Debrauwer L, Canlet C, Huc L, Dupuy J, Pierre FH, Guéraud F. ‘4-Hydroxy-2(E)-nonenal metabolism differs in Apc(+/+) cells and in Apc(Min/+) cells: it may explain colon cancer promotion by heme iron.’ Chem Res Toxicol. 2011 Nov 21;24(11):1984-93
Kallianpur et al. ‘Dietary animal-derived iron and fat intake and breast cancer risk in the Shanghai Breast Cancer Study.’ Breast Cancer Res Treat 2008;107:123–32
Ijssennagger N et al. ‘Dietary haem stimulates epithelial cell turnover by downregulating feedback inhibitors of proliferation in murine colon.’ Gut. 2011 Sep 27.
Reizenstein P. ‘Iron, free radicals and cancer.’ Med Oncol Tumor Pharmacother 1991;8:229–33.
Jakszyn P et al. ‘Dietary intake of heme iron and risk of gastric cancer in the European prospective investigation into cancer and nutrition (EURGAST- EPIC) study.’ Int J Cancer. 2011 Jun 29
Angeli JP et al. ‘Lipid hydroperoxide-induced and hemoglobin-enhanced oxidative damage to colon cancer cells.’ Free Radic Biol Med. 2011 Jul 15;51(2):503-1
There is also an interesting potentially positive paper that may be of interest. It is Corpet DE. ‘Red meat and colon cancer: should we become vegetarians, or can we make meat safer?’ Meat Sci. 2011 Nov;89(3):310-6.
My first sentence in my March 2012 feature aimed to establish the topic by stating: “There is no evidence that small quantities of red meat are harmful to health.” My statement about quantity came from the Dietary Guidelines for Australians which recommend 65-100g of red meat, three to four times a week.
Yours sincerely
Dr Rosemary Stanton OAM
Nutritionist
