Healthy planet eating - How lower meat diets can save lives and the planet
←
→
Page content transcription
If your browser does not render page correctly, please read the page content below
Healthy planet eating How lower meat diets can save lives and the planet istock Friends of the Earth October 2010 1
CONTENTS Executive summary 3 About this research Having investigated the environmental introduction 4 implications of a range of dietary options HOW MEAT CONSUMPTION HAS RISEN in 2009’s Eating the planet? report, OVER THE LAST 50 YEARS 6 Friends of the Earth commissioned Defining 'meat' 7 Oxford University’s British Heart Foundation Health Promotion Research the health impacts of Group to analyse their likely impact on: excess meat consumption 8 • specific health conditions How would reducing meat consumption improve health? 8 • mortality figures Cancer 10 • NHS expenditure Heart disease and stroke 12 Obesity 13 The meat and dairy content of the diets Premature death 14 investigated ranged from the high meat ALL MEAT IS NOT THE SAME 15 diets most common in western countries to a lower level of meat and dairy calls for change 17 consumption that could be produced Tracking what we eat 18 without eating into the planet’s natural We eat what we are told 19 resources, while allowing consumption HOW MUCH IS ‘LESS’ MEAT? 20 growth to sustainable levels in developing countries. NUTRIENT INTAKE 21 Nutrient 21 This report summarises the key Protein 22 findings of this analysis and presents Iron 23 a comprehensive literature review Children 24 of existing studies on the health The elderly 24 Low income groups 25 and environmental impact of meat consumption. RECOMMENDATIONS FOR A HEALTHIER BALANCE 26 REFERENCES 27 It concludes with a series of recommendations for healthy and sustainable diets and the policy shifts needed to drive changes. Acknowledgements Friends of the Earth October 2010 Research by Patricia Thomas. Modeling by Mike Rayner, Dushy Clarke and Pete Scarborough, British Heart Foundation Health Promotion Research Group, Department of Public Health, University of Oxford. The key findings of this report are based on research by Oxford University: Modelling the impacts of the Fair Less Meat diet. This research, including the modelling and methodology, is available at www.publichealth.ox.ac.uk/bhfhprg/publicationsandreports 2
Executive summary We are producing and consuming We could prevent 45,000 early deaths Clear standards should be introduced to increasing quantities of meat and dairy. and save the NHS £1.2 billion each year ensure that meals paid for by taxpayers This is taking its toll on the planet and on if we switched to diets that contain less in schools, hospitals and care homes our health – and very little is being done meat in the UK. reflect environmental and health factors to tackle it. and reduce reliance on meat and dairy in Lower-meat diets could cut deaths from menus. The livestock industry is one of the heart disease by 31,000, deaths from most significant causes of global cancer by 9,000 and deaths from strokes The Government should shift support environmental damage – generating by 5,000 each year. from factory farming to the production a fifth of the world’s greenhouse gas of better-quality meat and a healthier emissions. The UK’s reliance on imported There is clear evidence of a link between overall food production balance. protein crops is also driving deforestation high meat diets and a higher incidence in South America. This is having a of bowel cancer and heart disease with Grass-fed meat and dairy products are devastating impact on the people who’ve some evidence of a link between high healthier and more planet-friendly than lived on the land for centuries. meat diets and other cancers, diabetes factory farmed options. They should and obesity. be clearly labelled for consumers. This Friends of the Earth and Compassion in would help people make more informed World Farming’s 2009 research Eating Processed meat is more damaging to food choices and stimulate the market for the Planet? showed that a move to lower- health than unprocessed meats. these products. meat diets in the West would help protect natural resources and enable us to move Grass-fed beef has nutritional Friends of the Earth is calling on the away from factory farms and damaging advantages over grain-fed options. Government to implement these changes intensive crop production.1 It would also within the framework of a Sustainable allow for fair global food distribution and The nutritional value of some meat has Livestock Strategy. nutritious diets for people in developing decreased as a result of modern farming countries. methods. A standard supermarket chicken now contains significantly less This new research reveals how this diet protein and more than twice as much fat could deliver a fairer deal for people, as in 1970. animals and the planet and analyses its likely impact on the health of people in Key recommendations the UK. It also reviews existing evidence There is an undeniable need for on the relationship between meat and widespread adoption of healthier and dairy consumption and health. It outlines more sustainable diets and more the action needed to transform the UK’s research is urgently needed to identify food and farming sector into one that the best mechanisms for change. would work for people and the planet. Existing healthy eating and Key findings environmental behaviour guidelines Over the last 50 years the quantity of should be modified to include the benefits meat produced around the world has of eating less meat. quadrupled while the global population has doubled. 3
introduction Meat and dairy products form the In the media the issue has been over- centrepiece of most meals in the UK. simplified and distorted. Factory-style production and heavy For example, in October 2009 climate subsidies have made them plentiful and change expert Lord Stern observed that cheap in Europe and America. the environmental impact of a meat diet Our increasing consumption – of meat was higher than that of a vegetarian diet. in particular – is prompting concern over His comment was interpreted in reports the impacts on people’s health and on as “people will need to turn vegetarian if the environment. But calls for changes to the world is to conquer climate change”.3 diets and farming methods have tended Similarly, in January 2009 a plan to to produce a polarised and often ill- reduce the amount of meat served informed debate. in hospitals to healthier and more This report aims to throw fresh light on sustainable levels was included in an the stalemate. It does so by presenting NHS carbon reduction strategy.4 The evidence on the health benefits of proposal focussed on reducing meat, switching to lower-meat diets. rather than cutting it out entirely, and sourcing local produce, but was reported A cultural challenge as a “removal” and a “ban” on meat and There is little doubt about the science. was criticised in the media.5 The plan was In the West we eat far more meat than subsequently scrapped. is necessary or healthy. Health experts Ironically, we are more prepared than say this is contributing to rising levels of ever to throw meat away6. Historically chronic diseases such as coronary heart regarded as an indicator of affluence disease, cancers and strokes. and, for many, a treat, meat is now Such findings have led to calls for artificially cheap and plentiful. The nutritional advice to be revised to growing quantities wasted suggest that, encourage a reduction in total meat along with other food groups, meat has intake and discourage meat and dairy become a throwaway commodity. that is high in fat – particularly saturated So our attitudes towards meat are fat – and salt. Instead, small amounts of complex. What is clear is the damage better-quality fresh lean meat would be that increasing consumption is doing to recommended.2 the environment and people. Yet such thinking is not reflected in any UK Government guidelines or advice on Environmental and social damage healthy eating. Changing our concept Meat and dairy production – now of an average healthy diet is proving a responsible for a fifth of global challenge. greenhouse gas emissions – is predicted In the UK there tends to be an all- to double by 2050.7 This is incompatible or-nothing approach to meat eating, with the need to cut emissions by at least with little recognition or understanding 80 per cent in the same period to prevent of the concept of a low-meat diet. It’s the worst effects of climate change. 8 telling that, while people who eat no UK factory farms are also driving meat are identified and identifiable – as deforestation and ruining lives overseas. vegetarians – there is no commonly Vast areas of forest and wildlife in South accepted term for people who eat meat America are being cleared to grow the only a few times a week. protein needed to quickly bulk up millions Attempts to raise awareness of the of animals each year. This is forcing local benefits of lower-meat diets and to people off their lands and into hunger change diets have proved controversial. and poverty. 4
istock Martino/Panos Eduardo Cattle farm in the Brazilian Amazon An alternative and distribution are as compelling as the • reducing the burden of diet-related There is already evidence that environmental imperatives. disease on the NHS consuming less meat would be good for This report adds to the evidence by • helping to create a thriving and planet- the environment and would help feed a presenting modelling on the impact of a friendly UK farming sector. growing population. lower-meat diet on people’s health and This report sets out what the In 2009 Friends of the Earth and NHS budgets. It also reviews: Government needs to do to encourage Compassion in World Farming published • evidence of the health impacts of high healthy and sustainable diets and food Eating the planet?, a groundbreaking meat and dairy consumption production. report which demonstrated that we can • the difference between good and bad Grasping these opportunities would feed a growing global population without meat transform the UK into a model for destroying the world’s natural resources • examples of healthy alternative eating healthy, sustainable food production and or relying on factory farms – and we don’t advice and plans. consumption that, if adopted by the rest need to give up meat. Eating less meat is not a silver bullet of the world, would help ensure a fair The modelling in Eating the Planet? that will deliver healthy eating and share of the world’s food resources for showed that by adjusting our diets we living. But a growing body of evidence everyone. could feed a global population predicted shows that we should get the majority to be 9 billion by 2050. Rearing animals of our nutrients from fresh fruits and for food uses far more land, energy and vegetables, whole grains and pulses, water than growing crops to provide with only small amounts of meat, dairy people with the same number of calories. and fish as additional sources of protein. A diet containing no more than three Recommendations on fish consumption portions of meat each week would take when stocks are under threat are beyond pressure off the land and the climate. the scope of this report but are covered The diet outlined in Eating the Planet? by Greenpeace and Sustain.9 10 would mean a significant reduction in Such a diet has many benefits meat eating in the West, yet it would including: allow for more meat to be eaten in • reducing the livestock industry’s developing countries where there are environmental impact – including on high levels of malnutrition. There are climate change as many obese people in the West • improving the health and wellbeing of as there are malnourished people in people in the UK, and indeed the rest of poorer countries: the health and justice the world arguments for changes to food production 5
HOW MEAT CONSUMPTION HAS RISEN OVER THE LAST 50 YEARS Over the last fifty years there has been a middle class,14 although it is still well of the modern animal husbandry and dramatic rise in global meat consumption below European and US levels. Meat livestock farming practices. These with the growth in the global livestock consumption in China, for example, has developments allow us to produce population far outstripping that of the gone from an average of 20 kg per capita staggering amounts of meat and milk human population. in 1980 to 52 kg in 2008.15 Although in on relatively small parcels of land, and, Between 1961 and 2008 the world India meat consumption has grown by 40 because animal foods are rich in protein, population increased by a factor of 2.2,11 per cent in the 15 years to 2007, it is still as a boon to human health. but total meat consumption quadrupled 40 times less than average consumption But the World Health Organization – from 71 million tonnes to 280 million in the UK. (WHO) is among many organisations tonnes – and poultry consumption Between 1961 and 2008 the to suggest that in the West we now increased 10-fold – from 9 million tonnes consumption of dairy products has consume considerably more protein to 91 million tonnes.12 doubled – from 344 million tonnes to than is considered necessary or optimal According to the most recent data on 693 million tonnes.16 Dairy products are for health.17 At the same time it is clear meat eaten per person – from 2002 – the a good source of protein and a major that the population explosion in livestock United States leads the developed world source of calcium in the West. Dairy has not eased world hunger. In fact, in meat consumption with each American can also be high in fat and saturated fat. with nearly a billion people starving, a eating an average 125 kg of meat a year. However in response to public health question mark hangs over how rational, Per capita meat consumption in Europe campaigns to encourage lower total or ethical, it is to feed such a large averaged 74 kg, while the average UK fat and saturated fat in the daily diet, proportion of edible grains and proteins citizen consumed 80 kg13 – equivalent to there has been a substantial switch to to animals. 1,400 pork sausages each year, or nearly consuming more low-fat products over It is only recently that we have begun four a day. the last 20 years. to quantify the human health and Demand is also growing in some The abundance of meat and dairy in environmental consequences of this developing countries as a result of our diets is seen as an indication of our exponential growth in livestock production rising incomes and a growing urban increasing affluence and as a triumph and consumption. The Friends of the istock 6
Earth reports Eating the Planet?18 and The global spread of intensive farming greenhouse gas emissions – including What’s Feeding Our Food?19 show has led to a major increase in the 9 per cent of man-made global carbon that these burdens are both increasing diversion of cereals and other grains dioxide (CO2) emissions and 37 per cent and unsustainable and there are now away from the human food chain and into of anthropogenic methane.24 numerous pressing reasons for adopting animal production. For instance, today These are excesses – in pollution a lower-meat diet. 97 per cent of the soymeal and 40 per and resource use – that the world Compared to growing crops for direct cent of cereals produced worldwide are cannot support over the long term. But consumption, rearing animals for food used for animal feed. environmental excesses are not the only uses large areas of agricultural land, Animals’ feeding requirements mean impact of rising livestock consumption. vast quantities of water and significant that livestock uses 70 per cent of all Studies into human health are amounts of energy. It is a cause of available agricultural land, and uses 8 per beginning to show that, in the same way deforestation and land use change, cent of the global human water supply.23 that excess fat and excess sugar in the generating greenhouse gas emissions With growth in demand for livestock diet can be detrimental to health, excess and destroying valuable carbon sinks and products set to continue, more land and meat consumption can have profoundly wildlife habitat. The livestock industry more water – and more food that could negative consequences for our health is also a significant drain on energy be consumed directly by humans – is including higher rates of heart disease, resources: growing grain for livestock being turned over to feeding livestock, stroke, cancer, and premature death. requires large energy inputs in terms further exacerbating the associated At the same time it is becoming clear of fertilisers and pesticides. It is also a impacts. that all meats are not the same in terms significant source of pollution.20 Because of all these inputs, the of their impact on health. As the science The economic burden of animal food contribution of animal farming to the has become more sophisticated and consumption is also high because of production of greenhouse gases and begun to differentiate between fresh the large amounts of grain that need climate change is substantial. The meat and that which is preserved or to be grown to feed farmed animals.21 United Nations Food and Agriculture highly processed, data now shows that One kilogram of intensively-reared beef Organization (FAO) estimates it is the greatest negative impact on health requires up to 10 kg of animal feed.22 responsible for 18 per cent of global comes from consumption of the latter. Defining 'meat' In terms of sheer volume of raw materials ‘bad’) fats and carbohydrates and this refers to poultry and sometimes fish. and goods, modern farmers and food knowledge has been incorporated into In the scientific literature and in this producers are highly productive. Human healthy eating guidelines. report, processed and preserved meat beings have made substantial gains Just as there are ‘good’ and ‘bad’ are defined as any meat preserved by in health and longevity thanks to this fats and carbohydrates it is increasingly smoking, curing or salting, or with the productivity.25 However this abundance becoming acknowledged that there are addition of chemical preservatives, for has not benefitted mankind universally also ‘good’ and ‘bad’ meats. example bacon, salami, sausages, hot – 925 million people worldwide are In very early studies of meat intake dogs or processed deli or luncheon undernourished due to lack of access to little distinction was made between meats (including some white meats such good food in sufficient quantities.26 different types of meat, indeed ‘meat’ as turkey and turkey ham). This type of In addition, much of the abundance has no common definition in scientific meat often contains a number of harmful we enjoy is in the form of high fat, high research. More recent studies, substances including heterocyclic amines, sugar foods which are energy intensive to however, have begun to make important polycyclic aromatic hydrocarbons,29 and produce27 and also damaging to health.28 distinctions between fresh and preserved/ N-nitroso compounds30 formed in the Rising rates of obesity and chronic processed meats and between red and high temperature cooking of meat. The diet-related diseases suggest that in the white meats. nitrate and nitrite preservatives added midst of this abundance means we have In general, the term ‘red meat’ refers to to processed meats are also known ‘forgotten’ how to discriminate. Science beef, lamb and pork; as a broad category precursors to N-nitroso compounds (see is helping us to relearn this skill. We it includes both fresh and processed/ All Meat is not the same, page 15). now understand the difference between preserved meats. ‘White meat’ is less well healthy and unhealthy (or ‘good’ and defined but in scientific research usually 7
new research THE HEALTH IMPACTS OF EXCESS MEAT CONSUMPTION The health effects of reduced meat Yet studies show that excess meat in This requires strong, clear, consumption are becomming well general, and preserved and processed unambiguous guidance from health and established in the scientific literature. As meats in particular, can add high amounts food policy makers. As the data on the the study populations themselves have of fat, saturated fat and salt to the diet. harmful effects of consumption of excess become larger and as the methodology The most important health impacts of meat continues to amass, the case of such studies has become more excess fat and sodium include increased becomes stronger for a thorough re- sophisticated, the weight of the evidence risk of heart disease, stroke and cancer, evaluation of healthy eating guidelines. has grown. A valuable picture has as well as an increased incidence of emerged of how the balance of meat and obesity and premature death. How would reducing meat consumption dairy and other foods in our diets can act In contrast, diets where plant-based improve health? to improve or harm health. elements dominate are associated with New research carried out by Oxford Much of the early data on diet, lower body weight,32 greater longevity33 University’s British Heart Foundation lifestyle and health came from studying and a lower rate of certain chronic Health Promotion Research Group for vegetarian lifestyles. Other data comes diseases especially diabetes, heart Friends of the Earth used the DIETRON from long term observational studies disease, and some cancers.34 modelling system to analyse the health which look at what people eat and what The cost to the NHS of diet-related implications of a range of diet scenarios.36 diseases they develop over time. illness is estimated to be twice that of car, It concluded that switching from current Still more comes from intervention train and other accidents and more than diets to a diet that contains two or three studies where people who are suffering double that of smoking.35 Diet-related meat meals each week and a small from a chronic illness or who are at high illnesses, however, can be prevented. amount of dairy each day would prevent risk of illness are switched to more plant- It has been estimated that the NHS 45,361 deaths each year (see graph). based diets. could save around £6 billion a year if Such data highlights the health the excesses and inadequacies in our Table 1: Change in cost to the properties of a diet high in fruits, current diets could be addressed in the 2006/07 NHS budget (baseline 2007 UK diet) vegetables, unrefined grains and same proactive way adopted to address Disease Current Less Fair Less pulses and moderate amounts of meat the health impacts of smoking. New diet trends Meat Meat equivalents such as soy. Studies show modelling carried out by Friends of the CHD +£0.05bn -£0.57bn -£0.80bn that those who eat little or no meat and Earth shows that widespread adoption Stroke +£0.00bn -£0.07bn -£0.10bn dairy are often healthier than the general of lower-meat diets could prevent 45,000 Cancer +£0.02bn -£0.20bn -£0.30bn population.31 deaths and save the NHS £1.2 billion Total +£0.07bn -£0.85bn -£1.20bn However, it is a mistake to place too each year – see graph 1B. narrow an interpretation on these studies. There is firstly a tendency, particularly A note on the diets in older studies, to group all vegetarians and vegans together even though there These diet scenarios are based on Friends of the Earth and Compassion in World Farming’s are important differences in nutrient 2009 report Eating the planet? which analysed different diet options and farming methods to assess their impact on global food production and the feasibility of feeding the estimated intake between a strict vegan diet, a strict population in 2050 – nine billion. vegetarian diet, a lacto-ovo-vegetarian diet (which allows milk and eggs) and a ‘Current diet trends’ reflects the level of meat and dairy that will be eaten in the UK if lacto-ovo-pesce vegetarian diet (which trends around increasing consumption are projected into the future. allows dairy, eggs and fish). In addition ‘Less meat’ is based on satisfying growing food and nutritional demands with a lower meat to eating few or no animal products, diet with 30 per cent of protein from animal products. vegetarians and vegans also tend to ‘Fair less meat’ assumed a fair distribution of nutritionally sufficient diet that allows for meat practice other healthy activities that 2 or 3 times each week and some dairy each day. contribute to their overall level of health, including taking more exercise and In place of the contribution of meat and dairy, the ‘Less Meat’ and ‘Fair Less Meat’ diets include smoking less. more fruit and vegetables, and an increase in the amount of starchy carbohydrates. These changes, in combination with a reduction in saturated fat from meat and dairy and a reduction in salt from processed meats, are responsible for the predicted changes in health outcomes displayed in graph 1b and table 1. With a reduction in food waste and more fair food distribution and diets, this scenario would feed the world and allow for planet-friendly farming methods.37 8
Graph 1B: Change in annual mortality by cause (baseline 2008 average UK diet) 45,361 Current diet trends Less Meat Fair Less Meat 32,352 31,094 22,149 lives saved 8,920 6,176 5,346 4,027 4,610 3,083 1,610 2,321 1,552 1,077 50 464 379 Total deaths CHD Stroke Total cancer MLP cancer Oesoph. cancer Stomach cancer Lung cancer 202 491 102 292 147 increase in Deaths 2509 1817 9
how meat consumption affects health Cancer The relationship between diet and cancer of developing bowel cancer by 63 per Breast Cancer has become increasingly clear over the cent. The report went on to recommend A 2006 study which followed more than last few decades. Cancer is responsible limiting overall consumption of red meat 90,000 premenopausal women for 12 for 7.4 million deaths globally each to between 300 g (11 oz) - 500 g (18 oz) years50 found that, compared with those year, about 13 per cent of all deaths.38 a week – equivalent to around 2 ounces who eat three or fewer servings per week, The WHO estimates that 30 per cent daily – very little if any of which should women eating three to five servings of red of cancers in the developed world (and be processed meat. This compares to meat weekly have a 14 per cent higher risk 20 per cent in developing countries) are the current UK level of consumption of a hormone-dependant breast cancer, caused by dietary factors. In the UK it of around 190 g (6.6 oz) each day, while those eating more than five servings is estimated that 26 per cent of cancers according to the latest National Diet and a week have a 42 per cent increased risk. could be prevented by altering diet.39 Nurition Survey.45 Two of the largest studies so far, How meat intake causes cancer is the pan-European EPIC study51 which Colorectal cancer still not completely understood. There followed more than 300,000 women and The relationship between diet and is, for example, no strong association the US AARP Diet and Health study52 cancer is particularly strong for colorectal between high fat intake and bowel which followed more than 188,000 women, (bowel) cancer. In 2005 a European cancer risk independent of meat intake.46 have also found that that those who study involving more than a half a million One Swedish study, for instance, found eat the most saturated fat have a small people found that, amongst people who that women consuming the highest increased risk of breast cancer. regularly ate more than two portions of amounts of full-fat dairy products There are several ways in which meat red and processed meat a day, the risk of had a significantly lower risk of bowel intake could affect breast cancer rates. developing bowel cancer was 35 per cent cancer,47 and a randomised trial found Some observers suggest it is the result higher than for those who ate less than that switching to a low-fat diet offered of increased fat intake from red meat and one portion a week.40 no significant protection against the dairy.53 It has also been suggested that The conclusions of this study are disease.48 high dietary fat intake may increasing in line with the results of three meta- Instead it has been suggested that circulating levels of oestrogen and other analyses,41 42 43 which show a 20-30 per the contaminants and additives such hormones.54 The association between cent increased risk of bowel cancer in as nitrates in processed meat may be dietary fat and breast cancer, however, those eating 100-120 g/day of red meat influential (see page 15). remains controversial55 and not all studies and up to 50 per cent increased risk of The heme iron component of red meat show a link.56 bowel cancer in those eating 25-30 g/day (see page 23) is also associated with of processed meat. the generation of free radicals, highly Stomach and Bladder Cancer The broadest and most authoritative reactive molecules that can cause the Some,57 but not all,58 data links meat intake report on the link between meat and kind of cellular damage and mutations with bladder and stomach cancer and bowel cancer, however, comes from known to influence cancer and other this, research suggests, may be related the World Cancer Research Fund diseases. less to fat and more to the additives and (WCRF) which, over the last decade, Any or all of these mechanisms may contaminants in many red meat products. has forensically reviewed all the come into play, and even though the In a 2010 study of over 300,000 men available studies to date on the possible mechanisms are not fully understood, and women, those whose diets had the relationships between meat and dairy the strength of the evidence was such highest amount of total dietary nitrite (from intake and cancer.44 that the WCRF recommendation to limit all sources including meat), as well as The WCRF report found convincing red meat was quickly incorporated into those whose diets had the highest amount evidence that eating more than 500 g of UK Department of Health guidelines, as of nitrate plus nitrite from processed red meat each week significantly raised well as being recommended in a recent meats, had a 29 per cent increased risk of the risk of bowel cancer. In particular Cabinet Office report on food policy.49 developing bladder cancer.59 (For more on eating 150 g of processed meat a day Although the evidence is strongest for additives in processed meat see page 15). (equivalent to three sausages or three colorectal cancer, other cancers have also rashers of bacon) increases the risk been associated with high-meat diets. 10
Dairy and cancer – equivalent to that found in three cups In a 1998 Harvard study men who Links between dairy products and cancer of milk per day – were associated with a drank two or more glasses of milk a day are less conclusive. The WCRF found modestly higher risk of ovarian cancer, were almost twice as likely to develop that data for the relationships between compared to those with the lowest advanced prostate cancer as those who milk and dairy products and cancer was intakes.61 The study did not find any didn’t drink milk at all.64 The association, either “too sparse, too inconsistent, or association between overall milk or dairy however, appeared to be with calcium the number of studies too few to allow product intake and ovarian cancer. itself, rather than with dairy products in conclusions to be reached”.60 Likewise, some researchers have general. Some components of dairy products hypothesised that modern industrial Another more recent analysis of the have been linked to specific cancers milk production practices have changed same group of men found that those but it is not clear what would make one milk’s hormone composition in ways that with the highest calcium intake – at least person more vulnerable than another. could increase the risk of ovarian and 2000 mg a day; well in excess of daily For example, high levels of galactose, other hormone-related cancers.62 More recommended levels – had nearly double a sugar released by the digestion of research, however, is needed to confirm the risk of developing fatal prostate lactose in milk, have been linked to this. cancer as those who had the lowest ovarian cancer. The association is not The Western diet relies on milk as a intake (less than 500 mg per day).65 But absolute, but in a recent analysis of major source of calcium. In men a diet again, more study is needed to confirm 12 studies, which involved more than high in calcium has been implicated as a this finding. 500,000 women, high intakes of lactose risk factor for prostate cancer.63 Cancer protective foods istock Certain diets, for instance those with cancers,74 75 as well as some types of high intake of fruits and vegetables, are stomach cancer.76 But it has also found that cancer protective. Eating beans, peas fruit and vegetables are unlikely to reduce or lentils at least twice a week has been the risk of breast, prostate, ovarian or associated with a 50 per cent lower risk kidney cancers.77 78 79 of bowel cancer compared to those who Healthy fats, such as those found in never eat these foods,66 whereas the risk oily fish may be protective. In one study of developing the disease increases for the risk of bowel cancer decreased by those people who have a low-fibre diet.67 30 per cent amongst people who ate one Studies have found that people who eat portion or more of fish which contain the most fruit and vegetables can lower essential fatty acids every other day their risk of cancer by around 25 per cent compared to those who ate fish less compared to those who eat the least.68 than once a week (this study also linked 69 70 Specifically, including plenty of fruit low fibre intake to development of the and vegetables in the daily diet has disease).80 However not all studies show been shown to reduce the risk of mouth, a generalised benefit from increased oesophageal and laryngeal cancers by essential fatty acid consumption for all around a third71 72 and the risk of lung types of cancer.81 82 Many trials, however, cancer by around a quarter.73 use supplements in isolation rather than The ongoing pan-European EPIC fresh fish as part of a balanced diet, and study has found a similar protective this may affect outcomes. effect on mouth, oesophageal and lung 11
how meat consumption affects health Heart disease and stroke The relationship between excess meat unprocessed and processed red meat Data on fat and its relationship to and dairy and cardiovascular disease relates to the risk of heart disease, stroke heart disease is less clear. Several major (CVD, collectively heart disease and and also diabetes.85 The researchers studies86 87 88 have found no link between stroke) has been linked to the high identified and analysed 27 quality studies total fat intake and important health amounts of sodium and saturated fats in involving more than 1,200,000 people outcomes such as heart disease, cancer many of the meat and dairy products we from 10 countries on four continents. and even weight gain. consume. The researchers identified two reasons Fat is an essential nutrient and the It may come as no surprise that for the raised CVD risk. While both types body requires a balanced spectrum of there is a strong link with sodium. High of meat contained similar amounts of dietary fats to be healthy. Fat is a major blood pressure is a major risk factor fat, the amount of sodium in processed source of energy and aids the absorption for coronary heart disease and stroke. meats was four times that of fresh meat. of the fat-soluble vitamins A, D and While there are many risk factors for high Processed meats also contained 50 per E. It’s important for proper growth and blood pressure, high intake of sodium, cent more nitrate preservatives. development and cell and nerve function. a component of salt, is one of the most The results showed that, on average, Fats are an especially important source convincing.83 This is an area that has a 50 g (1.8 oz) daily serving of processed of calories and nutrients for infants and been generally well studied, and it has meat was associated with a 42 per toddlers. been shown that reducing salt intake can cent higher risk of developing heart However, not all fats are the same in also reduce the risk of Coronary Vascular disease and a 19 per cent higher risk terms of their impact on health and total Disease (CVD).84 of developing diabetes. In contrast, fat intake is probably less important to However, until recently sodium in eating unprocessed red meat was not heart health than the relative balance relation to meat intake has not been associated with risk of developing these of specific fats such as saturated and given much focus. diseases. Too few studies evaluated the unsaturated fats and the presence of In 2010 the Harvard School of Public relationship between eating meat and risk trans fats89 (see Heart-protective foods, Health conducted the first systematic of stroke to enable the researchers page 12 for more on fats). review and meta-analysis of the to draw any conclusions. Research has shown, for example, worldwide evidence for how eating that saturated fat can raise blood levels of "bad" low density lipoprotein (LDL) cholesterol, and that elevated LDL is a istock risk factor for heart disease and stroke. Because of this, most of us are advised to limit our intake of fatty meat, butter and full-fat dairy products – our main dietary sources of saturated fat. In 2010 an analysis that combined the results of 21 previous studies, and which included a total of nearly 348,000 adults followed for between 5 and 23 years, found no conclusive evidence that higher saturated fat intakes led to higher risks of heart disease or stroke.90 However, this analysis has been critiqued for having major flaws that have been pointed out in subsequent peer correspondence and articles.91 In the UK the trend for our overall intake of saturated fats is going down, but our intake is still too high (from 12.6-14.6 per cent of daily calories for adults when the ideal level is lower than 10 per cent). At least 48 per cent of the saturated fat in the UK diet comes from 12
Heart-protective foods istock Heart health, like all health, is dependent Essential fatty acids (EFAs) may also on a balanced intake of nutrients be protective. The UK Government now and it is likely that the rise in meat recommends a minimum intake of 1 per consumption in the West may have cent of energy from linoleic and similar occurred at the expense of heart- omega-6 polyunsaturated fats (found in protective foods such as wholegrains, large amounts in vegetable oils such as fruits and vegetables.98 99 100 sunflower and corn oils), and 0.2 per cent One of the largest and longest studies of energy from alpha-linolenic and similar into health and dietary habits followed long chain omega-3 polyunsaturated 110,000 American men and women for fats (found in large amounts in fish but 14 years. Those with the highest intake also in vegetable oils such as rape seed of fruits and vegetables (eight servings oil).104 This recommendation comes after or more a day) were 30 per cent less decades of research showing that higher A more specific dietary intervention, likely to have had a heart attack or stroke levels of EFAs can reduce the risk of substituting saturated fats with long chain compared to those with the lowest intake CVD, and other diseases. omega-3 fatty acids, has been shown (less than one-and-a-half servings a A recent analysis by researchers to lower the incidence of heart disease day). 101 at Harvard School of Public Health in several trials.107 108 109 These findings A later meta-analysis which included provided substantial evidence from warrant further investigation, but as a rule this US data along with several other randomized clinical trials that substituting the Western diet consumes omega-6 fatty long-term studies in the US and Europe, polyunsaturated fattty acids (PUFAs) acids to excess while levels of omega-3 found that people who ate more than five for some of our daily saturated fat can are generally deficient. Replacing some servings of fruits and vegetables per day reduce this risk by up to 19 per cent.105 meat in the diet with more vegetables, had roughly a 20 per cent lower risk of For every 5 per cent increase in PUFA wholegrain, pulses and oily fish, may coronary heart disease102 and stroke,103 consumption, coronary heart disease risk help rebalance fats in the diet by raising compared with those who ate less than was reduced by 10 per cent. This effect intakes of PUFAs and long chain three servings per day. has been noted elsewhere.106 omega-3 fatty acids. meat and dairy products92 which are also products saturated fats were replaced high calorie foods with overweight and the major sources of dietary cholesterol. with trans fats, which are also a particular obesity is ‘probable’ while the evidence Unlike the cholesterol that the body high risk for heart disease.95 96 Saturated linking meat and dairy consumption itself makes from exposure to sunshine, dietary fat has also been replaced by increased with overweight and obesity is ‘limited cholesterol can raise levels of cholesterol consumption of refined carbohydrates, and inconclusive’.111 in the blood,93 which in turn is a risk factor i.e. sugars which are also highly There are significant overall differences for atherosclerosis. Because the body important risk factors for heart disease.97 in weight between those who eat meat can make its own cholesterol, we have no and those who don’t. In a 2006 analysis real need of ‘extra’ cholesterol from our Obesity of the literature on diet and obesity, 29 food.94 A lower-meat diet could healthily out of 40 studies showed that non-meat meet our needs for fat, without adding Obesity is on the rise in the UK and eaters weighed significantly less than extra cholesterol which we do not need. throughout the world (including in meat-eaters. This was observed in both Over the past several decades, the developing countries where others males and females and across various food industry has reduced the amount are starving),110 and while there are ethnic groups.112 Generally speaking, of saturated fat in many products, and suggestions that this rise is linked with non-meat eaters also had healthier the public has reduced the amount higher intake of meat and dairy products, lifestyle habits such as more exercise of saturated fat in its diet. But there evidence is mixed. Some meat and dairy and less smoking, and this may have has been a wide variation in the types products can be high in calories and the influenced this outcome. However, the of nutrients that have replaced this WCRF suggests that the evidence linking authors note that, in some of the studies saturated fat. For example, in many the consumption of large amounts of reviewed, even when meat eaters and 13
how meat consumption affects health Obesity non-meat eaters had similarly healthy oxidant properties of heme iron, found cent higher risk of dying of cancer and a lifestyles the differences in weight only in animal products. High dietary 27 per cent higher risk of dying of heart remained. intake of heme iron as well as high body disease. For women the figures were 20 In another analysis comparing 55,459 stores of iron have previously been per cent and 50 per cent respectively. healthy women with omnivourous or associated with increased diabetes risk In relation to death from all causes, the vegetarian diets who were part of a in multiple studies,116 117 whereas dietaryresearchers estimated that 11 per cent of prospective breast cancer study, 40 non-heme iron (found only in plant foods) deaths in men and 16 per cent of deaths per cent of omnivorous women were was protective. Heme iron from fish and in women could be prevented if people overweight, compared to 29 per cent of poultry has also been associated with decreased their red meat consumption to semi-vegetarians and vegans, and 25 per diabetes risk118 (for more on heme iron around 5 ounces per week – a little less cent of lacto-ovo vegetarians.113 see page 23). than that recommended by the WCRF. Results from a study of 37,875 healthy Preliminary results from a European men and women participating in the Premature death study of vegetarians and non- pan-European EPIC study – the largest vegetarians, however, presented different single study of Western vegetarians Chronic disease increases the risk of findings.121 The study looked at the and vegans to date – found that after premature death. There is evidence that diets of 55,000 British meat eaters and adjusting for age, mean body mass a high intake of meat may make this vegetarians. The mortality of people in index (BMI) was significantly highest more likely and Friends of the Earth’s both categories in these studies is low among meat eaters (24.4 in men, 23.5 recent modelling supports this compared with national rates and overall in women) and lowest in vegans (22.4 (see page 8). mortality rates did not differ significantly in men, 21.9 in women). Individuals who A 2009 study from the London School between those who ate meat and those consumed no meat as well as fish eaters of Hygiene and Tropical Medicine119 who did not. Vegetarians had 11 per cent had comparable mean BMI which fell in explored the health and environmental higher mortality from all cancers, 13 per between the other groups.114 BMI is not a impacts of lower meat consumption. cent higher mortality from stroke, and particularly sophisticated measurement, It found that reducing consumption by 10 per cent higher mortality risk from all but it provides a rough estimate of a 30 per cent could reduce the greenhouse other causes, but a 7 per cent reduced person’s ‘fatness’ or ‘thinness’ based on gas emissions from livestock production mortality from all circulatory diseases and calculations of height and weight. as well as reducing the number of 25 per cent lower risk of death from heart The ‘normal’ range for BMI falls between people who die each year from heart attack. The authors suggest this is due to 18.5 and 25. attacks by 17 per cent (around 18,000 lower levels of cholesterol in the blood. individuals in the UK). The authors For all causes of death combined, Diabetes linked this reduction in mortality to a earlier comparative studies such as the Excess body weight is the most important reduction in saturated fat intake. Health Food Shoppers Study122 and the risk factor for diabetes. Although it is Also in 2009, in the largest study of Oxford Vegetarian Study123 also found common to think of diabetes as a disease its kind, researchers at the US National almost identical mortality amongst those associated with high intake of unrefined Cancer Institute assessed the association who did and did not eat meat. carbohydrates, several studies now show between meat intake and risk of death Why the data should be so conflicting is that high intake of meat, which contains among more than 500,000 individuals, unclear. The US study however involved no carbohydrate, increases the risk of aged 50 to 71 years old. They found that a significantly larger study population diabetes. A 2009 meta-analysis found older people who eat large amounts of and this may have given it greater power that high total meat intake increased red meat and processed meats faced to detect differences between the two type-2 diabetes risk 17 per cent above a greater risk of early death from heart dietary regimes, such as the wide range low intake, high red meat intake (around disease and cancer.120 of different meat consumptions and the 120 g per day) increased risk 21 per Participants were followed for 10 years. impact of red versus white meat and cent, and high processed meat intake Compared to those who ate the least red fresh meats versus processed meats. (around 50 g per day) increased risk 41 meat, and after adjusting for other risk However, the omnivores in the European per cent.115 factors such as smoking, family history of study may also have been generally more The reasons for this increased risk are cancer and high body mass index, men health conscious than average. not yet clear. One possibility is the pro- who ate the most red meat had a 22 per 14
ALL MEAT IS NOT THE SAME Preserved and processed meats could prevent 9, 35, 10 and 33 per cent cent of the salt in the UK diet comes from A study conducted by researchers from of colorectal, liver, lung and oesophageal these meat and dairy products.130 High the US National Cancer Institute found cancers respectively. salt intake, as previously noted, is one of a link between stomach cancer and the There is also data linking the red the clearest dietary causes of high blood consumption of heterocyclic amines in meat consumption and PhiP – the most pressure.131 cooked meats. The researchers found abundant heterocyclic amine in cooked In a recent study by Harvard that those who ate their beef medium- meat – and an increased risk of bladder researchers into the link between meat well or well-done had more than three cancer.126 intake and CVD, the researchers found times the risk of stomach cancer than Red meat is not the only problem. that while fresh and processed meats those who ate their beef rare or medium- The production of heterocyclic amines contained similar amounts of fat, the rare. They also found that people who ate (HCAs) can be more concentrated in amount of sodium in processed meats beef four or more times a week had more grilled chicken than in beef.127 One study was four times that of fresh meat. than twice the risk of stomach cancer as from New Zealand that investigated Processed meats also contained 50 per those consuming beef less frequently.124 levels of HCAs in meat, fish and chicken cent more nitrate preservatives. It was This was, admittedly, a very small found the greatest contributor of HCAs these risk factors, the researchers said, study. However in a much larger study to cancer risk was chicken.128 This could which linked higher intakes of processed of nearly half a million people in the US, explain why the consumption of chicken meat to higher risk of CVD.132 heterocyclic amines were also found to has also been linked to colon cancer: a As Table 2 below shows there are increase the risk of colorectal, liver, lung, 1998 study examined the eating habits of significant differences in the nutrients in and oesophageal cancers in those with 32,000 adults for six years and found that fresh and processed meats. high intakes of red meat compared to those who avoided red meat but ate white Processed meat contains less protein those with the lowest intake.125 Based meat regularly had a more than three-fold per 100 g than fresh meat. The fat and on 2500 calories a day, high intake in increase in the disease.129 sodium content of processed meat this study would equate to around 157 Preserved meats are also very high compared to their fresh counterparts is g or 4.5 ounces per day and low intake in salt. In the UK, most meat and dairy also significantly higher: a pork sausage, would be around 25 g, or 1 ounce per consumption is in the form of processed for example, has nearly three times more day. It was estimated that reducing meat foods (e.g. cheese, bacon, ham, fat and more than 14 times the sodium of intake in line with the lowest intake levels sausages, and ready meals) and 40 per a grilled pork steak. Table 2: FRESH VERSUS PROCESSED MEAT Mean daily intake+ g/100 g++ mg/100 g++ Men Women Protein Fat Iron Sodium FRESH MEAT Pork steaks** 32.4 7.6 1.10 76 Pork loin chops** no data no data 29.9 15.7 0.70 70 Pork diced casseroled*** 31.7 6.4 1.00 37 Total per day (week) 19 g (133 g) 9 g (63 g) Processed MEAT + Source: NDNS, 2008 133 Bacon* 18 g 10 g 23.8 26.9 0.80 1680 ++Source: McCance & Widdowson, 2002 134 Pork Sausages** 21 g 12 g 14.5 22.1 1.10 1080 * lean and fat, grilled Total per day(week) 39 g (273 g) 22 g (154 g) ** lean only ***streaky, grilled 15
istock This table highlights selected pork products only, but these differences hold true for most types of fresh versus processed meat products. It seems clear that adjusting our diets to eat less but better quality meat could make a substantial difference to protein, salt and fat intake without sacrificing nutritional adequacy. The differences make a compelling case for the nutritional advantage of less but better quality meat in the diet. Red meat versus white meat The term ‘red meat’ refers to beef, lamb and pork; as a broad category it includes The study also found that between One large and very recent study both fresh and processed/preserved 1980 and 2004, levels of the omega-3 published in the Journal of Animal meats. ‘White meat’ is less well defined fatty acid DHA in conventionally reared Science141 found that sirloin steaks and but in scientific research usually refers to chickens fell by 85 per cent between minced beef from grass-fed beef cattle poultry and sometimes fish. 1980 and 2004, while omega-6 – had lower total fat levels than those from The healthiest meats are lean meats the overabundance of which in our grain-fed cattle, almost four times as – regardless of their colour. With regard diets has been linked to diseases much omega-3 and slightly less omega-6 to blood cholesterol levels, there is no like cardiovascular disease, cancer, as grain-fed animals. The meat from particular advantage to eating lean white and inflammatory and autoimmune grass-fed animals also had almost twice instead of lean red meat.135 Comparison diseases139 – increased by 260 per cent. the level of CLA. of diets that include lean red meat and Grass-fed farming fits well into the lean white meat (in preference to more Grass-fed beef proposal that we should be eating less fatty meats) show similar benefits.136 Similar fatty changes have taken place but higher quality meat. With grass-fed In the UK, intake of ‘unhealthy’ red in red meats. Studies comparing the animals, herd sizes are naturally limited meats has dropped over the last few meat of intensively reared (ie grain fed to what the land can support, which decades while poultry consumption has and mainly housed) cattle with that from means we cannot over produce. Farming doubled.137 But intensively reared poultry grass-fed animals suggest that the diet within environmental limits reduces meat, fed on a diet of maize and soy, has and lifestyle of livestock – for instance, overall production levels compared to become increasingly fatty over the last whether the animal is grazed or fed on factory farming methods and has the 40 years. high protein artificial feed, whether it knock-on effect of encouraging more Recent data from researchers at gets exercise in a field or is confined to a optimum consumption levels. As part of London Metropolitan University has barren feedlot – can make a substantial a mixed farming system, grazed animals shown that a typical supermarket chicken difference to the composition and contribute to, rather than detract from, the today contains 2.7 times as much fat as balance of fats in its meat. health of the surrounding land.142 in 1970 and 30 per cent less protein.138 More than a dozen studies have now The relatively small amounts of Just 16 per cent of a chicken is now found that grass-fed cattle have a more essential fatty acids that could be derived protein, compared with almost 25 per desirable, higher ratio of the omega-3 from grass-fed meat in a reduced meat cent 35 years ago. As a result an average to omega-6 essential fatty acids.140 The diet may be insufficient on their own to serving of chicken contains almost 50 meat of grass-fed animals also has affect cardiovascular health, but the right per cent more calories than it used to. higher levels of beneficial conjugated balance between omega-3 and omega-6 Organic chicken had slightly more protein linoleic acid (CLA), as well as lower is particularly important for heart and 25 per cent less fat, but was still a overall levels of fat than grain-fed health.143 The more high-quality food we great deal fattier and less meaty than animals. have in our diets, the greater the likely chickens in the past. synergistic effect on health. 16
calls for change In the last year or so government In 2010 a major report into the changes “...likely to have the most agencies throughout the world have sustainability and resource use compiled significant and immediate impact on begun to make broad recommendations by the International Panel for Sustainable making our diets more sustainable, in for diets that meet our nutritional needs Resource Management for the United which health, environmental, economic without exhausting the limited resources Nations Environmental Programme and social impacts are more likely to of the planet. (UNEP)149 noted that the only way to feed complement each other”.151 In 2001, with the publication of its Third the world while reducing climate change A 2009 UK government report, Assessment Report144 on climate change is to switch to a less meat heavy diet." Securing Food Supplies up to 2050,152 the Intergovernmental Panel on Climate A substantial reduction of impacts”, notes that it is not enough to cut meat Change (IPCC) concluded that “a shift it said, “would only be possible with a production unless we also address meat from meat towards plant production for substantial worldwide diet change". consumption. That same year Lord human food purposes, where feasible, Commenting on the report Achim Nicholas Stern, author of the influential could increase energy efficiency and Steiner, Executive Director of the UNEP, 2007 Stern Review on the Economics decrease greenhouse gas emissions”.145 said that on reviewing all the available of Climate Change, gave an interview In 2009 the Swedish Government scientific evidence “...two broad areas to The Times newspaper in which he made a series of recommendations for are currently having a disproportionately warned that ‘business as usual’ scenarios cutting greenhouse gas emissions which high impact on people and the planet's would lead the world into economic and included eating less meat. It noted: “From life support systems - these are energy environmental disaster. a health perspective, there is also no in the form of fossil fuels and agriculture, One such scenario was our habitual reason to eat as much meat as we do especially the raising of livestock for consumption of meat: “I think it’s today".146 meat and dairy products”. He added important that people think about what Also in 2009 in the medical journal that ordinary consumers can help fight they are doing and that includes what the Lancet, members of an international climate change by eating less meat. they are eating.” He added: “Meat is a collaboration of scientists coordinated by In the UK there are no official wasteful use of water and creates a lot the Wellcome Trust suggested that there recommendations for reducing meat. of greenhouse gases. It puts enormous would be considerable health benefits The expert body on nutrition, the pressure on the world’s resources. from food and agriculture strategies Government's Scientific Advisory A vegetarian diet is better.”153 aimed at reducing greenhouse gas Committee on Nutrition (SACN), only In 2010 Sir Liam Donaldson, the UKs emissions.147 advises that: “Lower consumption of Chief Medical Officer, noted in his Annual In the US, nutritional recommendations red and processed meat would probably Report154 that meat and dairy contribute are for around 6 ounces (160 g) of meat reduce the risk of colorectal cancer... it substantially to global greenhouse gas or meat equivalent per day and are may be advisable for intakes of red and emissions and to chronic diseases such accompanied by copious information processed meat not to increase above as obesity, diabetes and heart disease. on what healthy meat equivalents are. It the current average (70 g/day) and for Commenting on his report he said: should be noted that this recommended high consumers of red and processed “Our diet is warming the planet. It is also intake is still substantial, though meat (100 g/day or more) to reduce their damaging our health. Changing our diet represents a significant reduction on intakes”.150 is difficult, but doing so would both help average daily US intake of around However, the mounting evidence on slow climate change and bring significant 8 ounces per day of meat and poultry. the health and environmental benefits health benefits...[reducing the UK's In an editorial accompanying the of meat reduction suggest that it is at consumption of animal products by 30 per analysis, Margaret Chan, Director the very least on the table for debate. cent by 2030] would reduce heart disease General of the World Health Organisation In 2009 the Sustainable Development by 15 per cent – a substantial reduction (WHO) offered the opinion that “reduced Commission (SDC), which advises the – and it would prevent 18,000 premature consumption of animal products in UK government on sustainability issues, deaths every year... These are contentious developed countries would bring public recommended that reducing consumption matters but they need to be openly health benefits.”148 of meat and dairy products was amongst debated and options weighed up.”155 17
You can also read