{"url":"https://whatshealthyandwhy.com/red-meat/is-red-meat-unhealthy","path":"/red-meat/is-red-meat-unhealthy","alternates":{"json":"https://whatshealthyandwhy.com/api/articles/red-meat/is-red-meat-unhealthy.json","markdown":"https://whatshealthyandwhy.com/red-meat/is-red-meat-unhealthy.md"},"topic":{"slug":"red-meat","name":"Red Meat","url":"https://whatshealthyandwhy.com/red-meat"},"slug":"is-red-meat-unhealthy","order":1,"title":"Is Red Meat Unhealthy?","question":"Is red meat unhealthy?","answer":"Eaten daily, red meat may slightly raise cancer and heart risk, but the evidence is weak; processed meat is the clearer concern.","description":"What the IARC rating, large cohorts and the NutriRECS review say about red meat, how much is reasonable, processed versus fresh, cooking, and grass-fed beef.","confidence":2,"confidenceNote":"Cohorts disagree, trials cannot test long-term outcomes, and the largest reviews rate the evidence for unprocessed red meat low-certainty or weak, though the processed meat link is firmer.","evidenceSummary":{"rctCount":0,"observationalCount":3,"metaAnalysisCount":6,"totalParticipants":"4,000,000+ (pooled cohorts)","replicated":false,"newestStudyYear":2022},"category":{"categoryTitle":"What's Good For You","categorySlug":"good-for-you","subcategoryName":"Foods & Drinks","subcategorySlug":"foods","url":"https://whatshealthyandwhy.com/explore/good-for-you/foods"},"actions":["Treat unprocessed red meat as occasional, not daily: Harvard estimated 7.6–9.3% fewer deaths under 42 g a day; PURE found no clear harm at 250+ g a week [3][4].","Cut back on processed meat first (bacon, ham, sausage, deli meats): in PURE, eating 150+ g a week went with 51% higher mortality, and the cancer link is stronger [1][4].","Some days swap in beans, lentils, nuts, fish or poultry: replacing red meat with plant protein (legumes, soy, nuts), but not fish or refined carbs, improved lipids in trials [5]."],"cautions":["With colorectal polyps or cancer, strong family history or hemochromatosis, ask your clinician how much red meat suits you: its heme iron is linked to colon cancer in cohorts [6].","If you are pregnant, iron-deficient or at risk of low B12, red meat is a rich source of both. Plan replacements before cutting it out, and see our [iron guide](/iron/iron-basics)."],"simpleText":"Eaten daily, red meat may slightly raise the risk of colorectal cancer, heart disease and early death, but the evidence is weaker than for processed meat. The WHO's cancer agency rates red meat \"probably carcinogenic\" and processed meat \"carcinogenic\" [1]. Large studies disagree, and a major review rated the evidence low-certainty with very small absolute risks [2]. Moderate portions and less processed meat is a sensible middle path.","mediumText":"How it works\n\nRed meat means beef, pork, lamb and goat. Processed meat is cured, smoked or salted (bacon, ham, sausages, deli meats). The International Agency for Research on Cancer placed red meat in Group 2A (probably carcinogenic) and processed meat in Group 1 (carcinogenic). Those labels describe how strong the evidence is, not how big the risk is [1]. In a meta-analysis of prospective studies, each 100 g a day of fresh red meat went with 17% higher colorectal cancer risk and each 50 g a day of processed meat with 18% [7].\n\nPossible reasons. Heme iron, the form in meat, may promote the formation of cancer-causing compounds in the gut. People with the most heme iron intake had 18% higher colon cancer risk in a pooled analysis [6]. Cooking meat at high heat creates other compounds (see our guide), and gut bacteria convert nutrients in red meat into TMAO (see our TMAO article).\n\nCohorts disagree. In 121,342 Harvard participants, each daily serving of unprocessed red meat went with 13% higher mortality and processed meat with 20% [3]. In PURE (134,297 people in 21 countries), unprocessed red meat at 250 g a week or more showed no significant link with death or cardiovascular disease, but processed meat at 150 g a week or more did [4]. In French NutriNet-Santé data, the highest red meat intake went with 31% higher overall cancer risk and 83% higher breast cancer risk [8].\n\nThe skeptics. A systematic review of 55 cohorts found that cutting 3 servings a week of red or processed meat was linked to very small risk reductions, with low-certainty evidence [2], and its guideline panel suggested adults keep their current red meat intake [9]. A newer evidence-rating method (the Burden of Proof approach) judged the evidence for unprocessed red meat weak [10].\n\nGrass-fed. Grass-fed beef has more omega-3 fats and conjugated linoleic acid per gram of fat, but similar total saturated fat, and health outcome data are missing [11]. See grass-fed meat and processed meat.","deepText":"The evidence in detail\n\nCancer. Chan and colleagues pooled prospective studies: the risk ratio for colorectal cancer was 1.17 (95% CI 1.05 to 1.31) per 100 g a day of fresh red meat and 1.18 (1.10 to 1.28) per 50 g a day of processed meat, rising roughly linearly to about 140 g a day. Rectal cancer showed no significant link [7]. Bastide and colleagues pooled studies of 566,607 people (4,734 colon cancers): the highest heme iron intake carried a relative risk of 1.18 (1.06 to 1.32). Rat experiments supported the mechanism [6]. In 61,476 NutriNet-Santé adults (1,609 cancers), the top fifth of red meat intake had hazard ratios of 1.31 for overall cancer and 1.83 for breast cancer, with none for prostate cancer; processed meat intake was low (top-fifth cut-off 46 g a day in men) and unrelated [8].\n\nDeath and heart disease. Pan's analysis of 37,698 men and 83,644 women found hazard ratios per daily serving of 1.13 (1.07 to 1.20) for unprocessed and 1.20 (1.15 to 1.24) for processed red meat for total mortality, and the authors estimated that 7.6% to 9.3% of deaths could be prevented if everyone ate under 0.5 servings a day [3]. These cohorts were health professionals who reported their diets on questionnaires. PURE found no significant link between unprocessed red meat at 250 g a week or more and mortality (HR 0.93, 0.85 to 1.02) or cardiovascular disease (1.01, 0.92 to 1.11), but processed meat at 150 g a week or more showed 1.51 (1.08 to 2.10) and 1.46 (1.08 to 1.98) [4].\n\nThe skeptical reviews. Zeraatkar and colleagues pooled 55 cohorts (more than 4 million people) and found that cutting 3 servings a week of unprocessed red meat was tied to very small decreases in cardiovascular mortality, stroke, heart attack and type 2 diabetes, with low certainty and a risk of confounding [2]. Their randomized trial review found 12 eligible trials, but the most credible was one trial of 48,835 women: diets lower in red meat made little or no difference to all-cause mortality (hazard ratio 0.99), cardiovascular mortality (0.98), total cancer mortality (0.95, 0.89 to 1.01) or colorectal cancer (1.04, 0.90 to 1.20). The gap in red meat intake between groups was small [12]. The NutriRECS panel (14 members, no funding) suggested adults continue current consumption of both unprocessed and processed meat, a weak recommendation based on low-certainty evidence, even though dietary guidelines generally advise limiting red meat [2][9]. Lescinsky and colleagues found weak evidence of links between unprocessed red meat and colorectal cancer, breast cancer, type 2 diabetes and ischemic heart disease, and none for stroke; the uncertainty interval for the minimizing intake spanned 0 to 200 g a day [10].\n\nTrials on risk markers. Guasch-Ferré's meta-analysis of 36 trials (1,803 people) found no significant differences in cholesterol or blood pressure between red meat and all comparison diets combined. Compared with high-quality plant proteins (legumes, soy, nuts), red meat gave smaller falls in LDL (0.198 mmol/L difference), but compared with fish it gave greater falls in LDL and HDL [5].\n\nGrass-fed. A review of research from three decades found grass-fed beef higher in conjugated linoleic acid, omega-3 fats, vitamin A and E precursors and antioxidant enzymes, with a distinct flavor, and noted grain-fed eaters could reach similar omega-3 and CLA intakes from higher-fat portions [11]. No study links these differences to better health outcomes.\n\nConflicts. Harvard's estimate (13% higher mortality per serving) and PURE's null result in 21 countries differ, and the trial evidence is weak. The disagreement may partly reflect what red meat is compared with: plant protein, fish or refined carbs.\n\nBottom line (confidence 2 of 5). Daily red meat may slightly raise cancer and heart risk, but evidence for unprocessed meat is low-certainty and absolute effects look small. Processed meat is the firmer concern. Small portions, not daily, and more plant protein is a defensible compromise.","deepTruncated":false,"references":[{"id":"1","title":"Carcinogenicity of consumption of red and processed meat","authors":"Bouvard V, Loomis D, Guyton KZ, et al.","year":2015,"journal":"Lancet Oncol","pmid":"26514947","url":"https://pubmed.ncbi.nlm.nih.gov/26514947/"},{"id":"2","title":"Red and Processed Meat Consumption and Risk for All-Cause Mortality and Cardiometabolic Outcomes: A Systematic Review and Meta-analysis of Cohort Studies","authors":"Zeraatkar D, Han MA, Guyatt GH, et al.","year":2019,"journal":"Ann Intern Med","pmid":"31569213","url":"https://pubmed.ncbi.nlm.nih.gov/31569213/"},{"id":"3","title":"Red meat consumption and mortality: results from 2 prospective cohort studies","authors":"Pan A, Sun Q, Bernstein AM, et al.","year":2012,"journal":"Arch Intern Med","pmid":"22412075","url":"https://pubmed.ncbi.nlm.nih.gov/22412075/"},{"id":"4","title":"Associations of unprocessed and processed meat intake with mortality and cardiovascular disease in 21 countries [Prospective Urban Rural Epidemiology (PURE) Study]: a prospective cohort study","authors":"Iqbal R, Dehghan M, Mente A, et al.","year":2021,"journal":"Am J Clin Nutr","pmid":"33787869","url":"https://pubmed.ncbi.nlm.nih.gov/33787869/"},{"id":"5","title":"Meta-Analysis of Randomized Controlled Trials of Red Meat Consumption in Comparison With Various Comparison Diets on Cardiovascular Risk Factors","authors":"Guasch-Ferré M, Satija A, Blondin SA, et al.","year":2019,"journal":"Circulation","pmid":"30958719","url":"https://pubmed.ncbi.nlm.nih.gov/30958719/"},{"id":"6","title":"Heme iron from meat and risk of colorectal cancer: a meta-analysis and a review of the mechanisms involved","authors":"Bastide NM, Pierre FH, Corpet DE","year":2011,"journal":"Cancer Prev Res (Phila)","pmid":"21209396","url":"https://pubmed.ncbi.nlm.nih.gov/21209396/"},{"id":"7","title":"Red and processed meat and colorectal cancer incidence: meta-analysis of prospective studies","authors":"Chan DS, Lau R, Aune D, et al.","year":2011,"journal":"PLoS One","pmid":"21674008","url":"https://pubmed.ncbi.nlm.nih.gov/21674008/"},{"id":"8","title":"Red and processed meat intake and cancer risk: Results from the prospective NutriNet-Santé cohort study","authors":"Diallo A, Deschasaux M, Latino-Martel P, et al.","year":2018,"journal":"Int J Cancer","pmid":"28913916","url":"https://pubmed.ncbi.nlm.nih.gov/28913916/"},{"id":"9","title":"Unprocessed Red Meat and Processed Meat Consumption: Dietary Guideline Recommendations From the Nutritional Recommendations (NutriRECS) Consortium","authors":"Johnston BC, Zeraatkar D, Han MA, et al.","year":2019,"journal":"Ann Intern Med","pmid":"31569235","url":"https://pubmed.ncbi.nlm.nih.gov/31569235/"},{"id":"10","title":"Health effects associated with consumption of unprocessed red meat: a Burden of Proof study","authors":"Lescinsky H, Afshin A, Ashbaugh C, et al.","year":2022,"journal":"Nat Med","pmid":"36216940","url":"https://pubmed.ncbi.nlm.nih.gov/36216940/"},{"id":"11","title":"A review of fatty acid profiles and antioxidant content in grass-fed and grain-fed beef","authors":"Daley CA, Abbott A, Doyle PS, et al.","year":2010,"journal":"Nutr J","pmid":"20219103","url":"https://pubmed.ncbi.nlm.nih.gov/20219103/"},{"id":"12","title":"Effect of Lower Versus Higher Red Meat Intake on Cardiometabolic and Cancer Outcomes: A Systematic Review of Randomized Trials","authors":"Zeraatkar D, Johnston BC, Bartoszko J, et al.","year":2019,"journal":"Ann Intern Med","pmid":"31569236","url":"https://pubmed.ncbi.nlm.nih.gov/31569236/"}],"wordCount":1053,"source":{"path":"src/content/topics/red-meat/is-red-meat-unhealthy.md"},"citeAs":"“Is red meat unhealthy?.” What's Healthy and Why. https://whatshealthyandwhy.com/red-meat/is-red-meat-unhealthy","notice":"General information backed by peer-reviewed research, not medical advice."}