A climatarian diet is a healthy option, reducing your risk of cancer, heart disease and stroke.
Major studies have revealed red and processed meat to be associated with an increased risk of colorectal, breast, prostate, pancreatic and stomach cancer.
A climatarian diet, avoiding beef and lamb in everyday meals and cutting down on meat overall, reduces these risks.
Replacing red meat with high quality plant protein like tofu, lentils, nuts, seeds etc. can lower your risk of heart disease and stroke.
A controversial study suggests otherwise
A study in 2019 found that there was insufficient or low-certainty evidence to suggest that red and processed meat are bad for your health. However, in response, authors of previous studies stand by their findings and have not changed their recommendations to reduce red and processed meat consumption some of which are outlined below.
A 2019 study conducted by an international panel led by Bradley Johnston an associate professor of community health at Dalhousie University in Halifax, Canada, found that there was insufficient or low-certainty evidence to suggest that red and processed meat are bad for your health. The panel conducted five systematic reviews of existing evidence. 11 of the 14 member panel voted for a recommendation to continue current red and processed meat consumption while 3 of the 14 voted for a weak recommendation to reduce red and processed meat consumption. The division of the panel and the stark contrast between its findings and the body of prior research makes it difficult for people to work out the truth and decide what is best for their health.
However, in response to the latest findings, authors of previous studies stand by their findings and recommendations to reduce red and processed meat consumption.
An analysis of the situation by The Guardian can be read here.
Red meat is mammalian muscle meat including beef, lamb, pork, goat and horse meat.
Red meat is classified as probably carcinogenic, Group 2A.
Processed meat is meat that has been salted, cured, smoked or fermented and includes corned beef, jerky, biltong, salami, ham, bacon, sausages and other meat based preparations.
Processed meat is classified as carcinogenic, Group 1.
Red and processed meat and cancer
Red meat is classified as probably carcinogenic associated with colorectal, prostate and pancreatic cancer.
Processed meat is classified as carcinogenic and is associated with colorectal, stomach and breast cancer.
In 2015 the International Agency for Research on Cancer review of scientific reports for the World Health Organisation resulted in the classification of processed meat as carcinogenic to humans (Group1) based on sufficient evidence in humans that the consumption of processed meat causes colorectal cancer, and associations were also seen with stomach cancer. It classified red meat as probably carcinogenic to humans (Group 2A). This association was observed mainly for colorectal cancer, but associations were also seen for pancreatic cancer and prostate cancer.
Results of a 2019 UK Biobank study of nearly half a million people carried out over five years found that people who were consuming red and processed meat four or more times per week, had a 20% increased risk of colorectal cancer compared with those who were consuming red and processed meat less than twice a week.
The same study found that consumption of red and processed meat at an average level of 76 g/day (2.7 ounces/day) was associated with an increased risk of colorectal cancer whereas fibre from bread and breakfast cereals can help reduce the risk.
A 2018 International Journal of Cancer analysis of prior studies on the relationship of red and processed meat to breast cancer found processed meat consumption to be associated with a 9% increased risk of breast cancer.
Red and processed meat and heart disease
Red and processed meat consumption is associated with an increased risk of heart disease and stroke.
Substituting red meat with high quality plant food lowers your risk of heart disease and stroke, even after just a month.
A 2019 analysis of thirty-six studies totalling 1,803 participants looking at heart disease risk factors in red meat consumption and other diets concluded that substituting red meat with high-quality plant protein sources lowers the risk of heart disease.
A 2018 Cleveland Clinic study published in the European Heart Journal links red meat consumption to an increased risk of heart disease and stroke. It also found that a month after ceasing consumption the risk was reduced.
A 2009 study of half a million people concluded that red and processed meat consumption was associated with modest increases in total mortality, cancer mortality and cardiovascular disease mortality.
Current dietary guidelines
US and UK dietary guidelines recommend limiting consumption of red and processed meat to one weekly serving (US) or 70g/day (UK) while the World Cancer Research Fund/American Institute for Cancer Research recommend limiting red meat consumption to moderate amounts and consuming very little processed meat.
International Agency for Research on Cancer. Volume 114: “Consumption of red meat and processed meat”. IARC Working Group. Lyon; 6–13 September, 2015. IARC Monographs on the Evaluation of Carcinogenic Risks to Humans (2018). Published by the International Agency for Research on Cancer 2018. Copyright 2018.
Cancer Research UK https://scienceblog.cancerresearchuk.org/2019/04/26/bacon-salami-and-sausages-how-does-processed-meat-cause-cancer-and-how-much-matters/ accessed 23 May 2019.
Kathryn E Bradbury, Neil Murphy, Timothy J Key, “Diet and colorectal cancer in UK Biobank: a prospective study”, International Journal of Epidemiology, dyz064,
Marta Guasch-Ferré, Ambika Satija, Stacy A. Blondin, Marie Janiszewski, Ester Emlen, Lauren E. O’Connor, Wayne W. Campbell, Frank B. Hu, Walter C. Willett, Meir J. Stampfer, “Meta-Analysis of Randomized Controlled Trials of Red Meat Consumption in Comparison With Various Comparison Diets on Cardiovascular Risk Factors”, 9 Apr 2019 Circulation, 9 April 2019;139:1828–1845,
Maryam S. Farvid, Mariana C. Stern, Teresa Norat, Shizuka Sasazuki, Paolo Vineis, Matty P. Weijenberg, Alicja Wolk, Kana Wu, Bernard W. Stewart, Eunyoung Cho, “Consumption of red and processed meat and breast cancer incidence: A systematic review and meta‐analysis of prospective studies”, International Journal of Cancer, Volume 143, Issue 11,1 December 2018, Pages 2787-2799 Published online 5 September 2018,
Wiley. “Processed meat consumption linked to breast cancer risk.” Science Daily, 2 October 2018.
Zeneng Wang, Nathalie Bergeron, Bruce S Levison, Xinmin S Li, Sally Chiu, Xun Jia, Robert A Koeth, Lin Li, Yuping Wu, W H Wilson Tang, Ronald M Krauss, Stanley L Hazen, “Impact of chronic dietary red meat, white meat, or non-meat protein on trimethylamine N-oxide metabolism and renal excretion in healthy men and women”, European Heart Journal, Volume 40, Issue 7, 14 February 2019, Pages 583-594,
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;169(6):562–571. doi:10.1001/archinternmed.2009.6
Johnston BC, Zeraatkar D, Han MA, et al. Unprocessed Red Meat and Processed Meat Consumption: Dietary Guideline Recommendations From the Nutritional Recommendations (NutriRECS) Consortium. Ann Intern Med. 2019; [Epub ahead of print 1 October 2019]. doi: 10.7326/M19-1621 Accessed 1.10.19