Can meat be part of a healthy diet? Do vegans miss out? Why do some go back to eating meat? What are the environmental and ethical issues? Should we eat meat?
Twelve per cent of UK adults are vegetarian or vegan, one in eight meat-eaters would like to eat less meat1 and the meat-free food market is booming. A recent report found that people become vegetarian for different reasons and this affects their commitment.2 For current vegetarians and vegans the motivation was animal welfare, feelings of disgust about meat and concern for the environment. For ex-vegetarians the motivation was health. So why is the health argument failing? It’s a combination of confusion, conflicting advice and disinformation from the £7.5 billion3 meat industry.
We have no dietary need for meat. All the key nutrients: protein, omega-3 fats, iron, zinc, iodine, calcium, vitamins D and B12 can be obtained from a vegetarian or vegan diet. Vegetarians tend to eat less saturated fat and cholesterol and more fruits, vegetables, wholegrain foods, nuts, seeds, fibre and antioxidants.4 They also tend to have higher intakes of essential fatty acids.5 The American Dietetic Association say: “…appropriately planned vegetarian diets, including total vegetarian or vegan diets, are healthful, nutritionally adequate, and may provide health benefits in the prevention and treatment of certain diseases.” 6
‘A meat-free diet lacks protein’
Vegetarian or vegan diets can provide all the protein you need during all stages of life, including pregnancy, lactation, infancy, childhood, adolescence and for athletes.6
‘Without meat we can’t get enough iron’
Iron deficiency is no more common among vegetarians than meat-eaters.6 One of the largest studies of vegetarians (and vegans), the EPIC Oxford study, compared over 33,000 meat-eaters, 18,000 vegetarians and 2,500 vegans and found that vegans had the highest intake of iron, followed by vegetarians then meat-eaters.7
‘Animal foods are the only source of B12’
It’s a misconception that vitamin B12 is only available from animal foods. Just as we can’t make B12, neither can most animals, they obtain it from bacteria on the plants they eat. Industrially produced B12 is used to fortify foods and make supplements. This type of B12 is easier to absorb than B12 from animal protein and as B12 deficiency increases with age, the US Institute of Medicine of the National Academy of Sciences recommends that all adults over 50 should take supplements or fortified foods.8 B12 is available from many fortified foods, including veggie burger mix, yeast extract, margarine, breakfast cereals and plant milks.
‘Red-blooded men need meat’
The idea that men need meat to perform sexually couldn’t be more wrong. A diet rich in fruit, vegetables, wholegrain foods, pulses, nuts and seeds and low in red and processed meat and refined grains protects against blocked arteries, heart disease, stroke and lowers the risk of impotence9 which may be an early warning of heart disease.10 Vegan fire-fighter Rip Esselstyn (son of esteemed heart surgeon Dr Caldwell Esselstyn) says “the canary in the coal mine when it comes to heart disease is an underperforming penis”.
‘Chicken is the healthy option’
In the 1970s, chicken was heralded as the ‘healthy’ option to red meat. Selective breeding and intensive farming methods have changed the nature of chicken meat, which now contains more than twice as much fat than it did in 1940. Organic chickens are not much better as they are also fed the same high-energy feed for rapid growth.
LESSONS FROM HISTORY…
WHEAT-EATERS OR MEAT-EATERS?
Carnivores (cats, dogs and wolves) have strong jaws that can only move open and shut and sharp teeth and claws to tear off chunks of raw meat and ‘wolf’ them down. Their acidic stomachs help digest flesh and short intestines allow the quick expulsion of rotting meat. Herbivores (rabbits, horses and sheep) chew from side-to-side, their saliva contains digestive enzymes and they have longer intestines to absorb nutrients. “Although most of us conduct our lives as omnivores, in that we eat flesh as well as vegetables and fruits, human beings have characteristics of herbivores, not carnivores.”11 Researchers from Harvard University say that modern humans do not cope well on raw diets that include meat.12 Indeed, meat-eating may have necessitated cooking because raw meat is difficult for humans to chew.13
THE PALAEO DIET MYTH
In the 1980’s US anthropologists Boyd Eaton and Melvin Konner suggested the Palaeolithic diet as a model for modern human nutrition.14 The Palaeo (hunter-gatherer) diet contains high protein (meat and fish but no dairy) and fibre but no grains or pulses. Proponents say the mismatch between this and modern diets is to blame for high levels of obesity, diabetes and heart disease. However, we have evolved to be flexible eaters15 and genetic evidence shows that we continued to evolve over the last 40,000 years, well into the Neolithic era.16 Modern adaptations include increased amylase production in response to carbohydrate (starch) consumption17 and geochemical analysis of grains and pulses from Neolithic sites reveal that early farmers relied much more heavily on plant protein than previously thought.18
‘MEAT MADE US SMART’ IS A DUMB IDEA
In the 1990’s British scientists Leslie C. Aiello and Peter Wheeler proposed the ‘expensive-tissue hypothesis’19 whereby there is a trade-off between the size of the digestive tract and the brain. The brain is ‘expensive’ because it requires so much energy and a high-quality diet enabled us to reduce the size of our digestive tract and free up energy to increase brain size. In other words ‘meat made us smart’. Recent research, published in Nature, refutes this saying a higher quality diet, coupled to energy saved by walking upright, growing more slowly and reproducing later, fuelled the growth in brain size20. Prehistoric humans ate some meat but it didn’t make them smart.
Compared to meat-eaters, vegetarians weigh less21 have lower cholesterol, blood pressure and rates of type 2 diabetes.6 Vegetarians have a 32 per cent lower risk of heart disease.22 The widespread adoption of a vegetarian diet could prevent around 40,000 deaths from heart disease in Britain each year.23 Research from Oxford University found that cancer incidence was 11 per cent lower in vegetarians and 19 per cent lower in vegans.24 The Adventist Health Study II from the US reported similar findings.25 The World Health Organisation says that up to 80 per cent of cases of heart disease, 90 per cent of type 2 diabetes and one-third of cancers can be avoided by changing to a healthier diet, increasing physical activity and stopping smoking.26 They say there are health benefits in eating more fruit, vegetables, nuts and wholegrain foods and moving to unsaturated plant-based fats.26
THE SAT FAT SCANDAL
Cholesterol rates in the UK are among the highest in the world. High levels are caused by saturated fat from meat, sausages, bacon, pies, cakes, biscuits, cheese and cream. The government recommends eating less of these and more foods containing unsaturated fats27 such as avocados, nuts, seeds, plant-based oils and spreads. However, a recent study in the Annals of Internal Medicine gave rise to the headline “Saturated fat 'ISN'T bad for your heart'”.28 Numerous academics criticised the study; Professor Walter Willett, chair of the Department of Nutrition at Harvard School of Public Health, said it contained major errors and omissions and the conclusions were seriously misleading.29 All major health organisations agree that saturated fat is a risk factor for heart disease.
DETRIMENTAL HEALTH EFFECTS
Red and processed meat can cause a 20-30 per cent higher risk of bowel cancer30. High intakes are also linked to an increased risk of type 2 diabetes.31 Red and processed meat may increase the risk of other cancers too, including that of the pancreas32 and stomach33. The World Cancer Research Fund say that people should “Eat mostly foods of plant origin, limit intake of red meat and avoid processed meat.” 34 That means no sausages or bacon, ever.
A review of studies, with over 1.5 million participants, published in the British Journal of Nutrition found that people who ate the most processed meat were more likely to suffer an early death with 18 per cent more likely to die from cardiovascular disease than those eating the least.35 Red meat was not far behind at 16 per cent. The Department of Health’s advice is to eat no more than70g a day. 36
The University of Cambridge’s Institute of Public Health estimated what would happen if meat intake fell and the number of vegetarians doubled.37 They predicted a drop in incidence of heart disease, stroke, diabetes, bowel cancer and other cancers, and a reduction in greenhouse gas emissions.
Livestock farming requires vast amounts of land, water and fuel, harms biodiversity and leads to species extinctions.38 What’s the connection between a Sunday roast and the loss of Amazonian rainforest? Soya, most of which is used for animal feed.39 It is a phenomenally wasteful system that devastates ecosystems, pollutes oceans, rivers, seas and air, uses up water, oil and coal and contributes to climate change. The United Nations’ ground-breaking report, Livestock’s Long Shadow, reveals how livestock farming is responsible for more greenhouse gas emissions than all the world’s transport combined (cars, buses, trucks, trains, ships and planes).40 It takes far more resources to feed a meat-eater than a vegetarian; animal protein requires five to 10 times more water than vegetable protein. Leading water scientists have issued stern warnings about global food supplies, saying that the world’s population may have to switch almost completely to a vegetarian diet to avoid catastrophic shortages.41 Meat and dairy consumption at current rates is simply not sustainable.
The increasing demand for cheap meat has inevitably led to a drop in welfare standards as factory-farming methods intensify. Chickens are crammed into sheds with no room for movement or compassion. Mothering sows are routinely caged to deliver and feed. Zero-grazing cows never see a field. Every year in Britain, over a billion animals face slaughter.42 Most spend their short lives in confinement, pain and misery. These intensive methods are not without consequence. Over 90 per cent of retail chickens are contaminated with faecal matter.43 Last November, the Food Standards Agency reported that seven in ten chickens sold in Britain’s supermarkets are infected with the food poisoning bug Campylobacter.44 Then of course there is horsemeat, E. coli 157, avian flu and BSE… It’s a wonder anyone risks eating meat.
A huge body of evidence shows that meat is not essential and that plant-based diets support good health and lower the risk of many diseases. Despite the overwhelming benefits of dropping or reducing meat consumption, it is not yet Government policy and that may have more to do with vested interests than it does science.
- Mintel (2014). Number of global vegetarian food and drink product launches doubles between 2009 and 2013 www.mintel.com/press-centre/food-and-drink/number-of-global-vegetarian-f...
- K Asher, C Green, H Gutbrod, M Jewell, G Hale and B Bastian (Animal Welfare Trust, VegFund, FARM and Stephen Kaufman, MD) (2014). Study of Current and Former Vegetarians and Vegans http://spot.humaneresearch.org/2014vegstudy
- Defra (2014). Agriculture in the United Kingdom 2013 www.gov.uk/government/uploads/system/uploads/attachment_data/file/315103...
- Rautiainen S, Levitan EB, Orsini N, Åkesson A, Morgenstern R, Mittleman MA, Wolk A (2012). Total antioxidant capacity from diet and risk of myocardial infarction: a prospective cohort of women. Am J Med; 125(10):974-980.
- Pan A, Chen M, Chowdhury R, Wu JH, Sun Q, Campos H, Mozaffarian D, Hu FB 2012. α-Linolenic acid and risk of cardiovascular disease: a systematic review and meta-analysis. Am J Clin Nutr; 96(6):1262-1273.
- Craig WJ, Mangels AR; American Dietetic Association. 2009. Position of the American Dietetic Association: vegetarian diets. J Am Diet Assoc; 109(7):1266-1282.
- Davey GK, Spencer EA, Appleby PN, Allen NE, Knox KH, Key TJ. 2003. EPIC-Oxford: lifestyle characteristics and nutrient intakes in a cohort of 33 883 meat-eaters and 31 546 non meat-eaters in the UK. Public Health Nutr; 6(3):259-269.
- Institute of Medicine (US) Standing Committee on the Scientific Evaluation of Dietary Reference Intakes and its Panel on Folate, Other B Vitamins, and Choline (1998). Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. Washington (DC): National Academies Press (US). www.ncbi.nlm.nih.gov/books/NBK114302/
- Esposito K, Giugliano F, De Sio M, Carleo D, Di Palo C, D'Armiento M, Giugliano D 2006. Dietary factors in erectile dysfunction. Int J Impot Res; 18(4):370-374.
- Böhm M, Baumhäkel M, Teo K, Sleight P, Probstfield J, Gao P, Mann JF, Diaz R, Dagenais GR, Jennings GL, Liu L, Jansky P, Yusuf S; ONTARGET/TRANSCEND Erectile Dysfunction Substudy Investigators (2010). Erectile dysfunction predicts cardiovascular events in high-risk patients receiving telmisartan, ramipril, or both. Circulation; 121(12):1439-1446.
- Roberts WC (2000). Twenty questions on atherosclerosis. Proc (Bayl Univ Med Cent); 13(2):139-143.
- Carmody RN, Wrangham RW (2009). Cooking and the human commitment to a high-quality diet. Cold Spring Harb Symp Quant Biol; 74:427-34.
- Luca F, Perry GH, Di Rienzo A (2010). Evolutionary adaptations to dietary changes. Annu Rev Nutr; 30:291-314.
- Eaton SB, Konner M (1985). Paleolithic Nutrition – A Consideration of Its Nature and Current Implications. N Engl J Med; 312(5):283-289.
- Henry AG, Brooks AS, Piperno DR. (2014). Plant foods and the dietary ecology of Neanderthals and early modern humans. J Hum Evol; 69:44-54.
- Hawks J, Wang ET, Cochran GM, Harpending HC, Moyzis RK (2007). Recent acceleration of human adaptive evolution. Proc Natl Acad Sci; 104(52):20753-2078.
- Turner BL, Thompson AL (2013). Beyond the Paleolithic prescription: incorporating diversity and flexibility in the study of human diet evolution.Nutr Rev; 71(8):501-510.
- Bogaard A, Fraser R, Heaton TH, Wallace M, Vaiglova P, Charles M, Jones G, Evershed RP, Styring AK, Andersen NH, Arbogast RM, Bartosiewicz L, Gardeisen A, Kanstrup M, Maier U, Marinova E, Ninov L, Schäfer M, Stephan E (2013). Crop manuring and intensive land management by Europe’s first farmers. Proc Natl Acad Sci; 110(31):12589-12594.
- Aiello LC, Wheeler P (1995). The Expensive-Tissue Hypothesis: The Brain and the Digestive System in Human and Primate Evolution. Curr. Anthropol; 36(2):199-221.
- Navarrete A, van Schaik CP, Isler K (2011). Energetics and the evolution of human brain size. Nature;480(7375)91-93.
- Fontana L, Klein S, Holloszy JO (2006). Long-term low-protein, low-calorie diet and endurance exercise modulate metabolic factors associated with cancer risk. Am J Clin Nutr; 84 (6):1456-1462.
- Crowe FL, Appleby PN, Travis RC, Key TJ (2013). Risk of hospitalization or death from ischemic heart disease among British vegetarians and nonvegetarians: results from the EPIC-Oxford cohort study. Am J Clin Nutr; 97(3):597-603.
- Key TJ, Davey GK, Appleby PN (1999). Health benefits of a vegetarian diet. Proc Nutr Soc; 58(2):271-275.
- Key TJ, Appleby PN, Crowe FL, Bradbury KE, Schmidt JA, Travis RC (2014). Cancer in British vegetarians: updated analyses of 4998 incident cancers in a cohort of 32,491 meat eaters, 8612 fish eaters, 18,298 vegetarians, and 2246 vegans. Am J Clin Nutr; 100(Supp 1):378S-385S.
- Tantamango-Bartley Y, Jaceldo-Siegl K, Fan J, Fraser G (2013). Vegetarian diets and the incidence of cancer in a low-risk population. Cancer Epidemiol Biomarkers Prev; 22:286–94.
- WHO (2003). Global strategy on diet, physical activity and health. www.who.int/dietphysicalactivity/media/en/gsfs_general.pdf
- NHS Choices (2013). Eat less saturated fat www.nhs.uk/Livewell/Goodfood/Pages/Eat-less-saturated-fat.aspx
- Chowdhury R, Warnakula S, Kunutsor S, Crowe F, Ward HA, Johnson L, Franco OH, Butterworth AS, Forouhi NG, Thompson SG, Khaw KT, Mozaffarian D, Danesh J, Di Angelantonio E (2014). Association of dietary, circulating, and supplement fatty acids with coronary risk: a systematic review and meta-analysis. Ann Intern Med; 160(6):398-406.
- Willett W (2014). Dietary Fat and Heart Disease Study is Seriously Misleading. www.hsph.harvard.edu/nutritionsource/2014/03/19/dietary-fat-and-heart-di...
- Aune D, Chan DS, Vieira AR, Navarro Rosenblatt DA, Vieira R, Greenwood DC, Kampman E, Norat T (2013). Red and processed meat intake and risk of colorectal adenomas: a systematic review and meta-analysis of epidemiological studies. Cancer Causes Control; 24(4)611-627.
- Aune D, Ursin G, Veierød MB (2009). Meat consumption and the risk of type 2 diabetes: a systematic review and meta-analysis of cohort studies. Diabetologia; 5(11):2277-2287.
- Stolzenberg-Solomon RZ, Cross AJ, Silverman DT, Schairer C, Thompson FE, Kipnis V, Subar AF, Hollenbeck A, Schatzkin A, Sinha R (2007). Meat and meat-mutagen intake and pancreatic cancer risk in the NIH-AARP cohort. Cancer Epidemiol Biomarkers Prev; 1(12):2664-2675.
- Song P, Lu M, Yin Q, Wu L, Zhang D, Fu B, Wang B, Zhao Q. 2014. Red meat consumption and stomach cancer risk: a meta-analysis. J Cancer Res Clin Oncol; 140(6) 979-992.
- WCRF (2007). Food, Nutrition, Physical Activity, and the Prevention of Cancer: a Global Perspective www.dietandcancerreport.org/cancer_resource_center/downloads/chapters/ch... Pages 380 and 382.
- Abete I, Romaguera D, Vieira AR, Lopez de Munain A, Norat T (2014). Association between total, processed, red and white meat consumption and all-cause, CVD and IHD mortality: a meta-analysis of cohort studies. Br J Nutr; 11(5):762-775.
- NHS (2013). Red meat and the risk of bowel cancer www.nhs.uk/Livewell/Goodfood/Pages/red-meat.aspx
- Aston LM, Smith JN, Powles JW (2012). Impact of a reduced red and processed meat dietary pattern on disease risks and greenhouse gas emissions in the UK: a modelling study. BMJ Open; 10;2(5).
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- WWF (2014). The Growth of Soy: Impacts and Solutions. WWF International, Gland, Switzerland.
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- Cho B, Kim MS, Chao K, Lawrence K, Park B, Kim K (2009). Detection of fecal residue on poultry carcasses by laser-induced fluorescence imaging. J Food Sci; 74(3)E154-159.
- FSA (2014). Retail survey on levels of campylobacter in chicken published. www.food.gov.uk/news-updates/news/2014/13251/campylobacter-survey