Should We All Give Up Meat to Save the Planet?

Pamela Mason, PhD

Public Health Nutritionist

Edinburgh Science Fair April 6, 2018

Outline

• What are the health impacts of the average British diet?
• Should we eat less red and processed meat, and what should we replace it with?
• What would be the environmental effects of such changes?
• What can we do as individuals/what should the government do?

What are the health impacts of the average British Diet?

• The burden of diet related ill health is substantial – estimated to lead to 70,000 premature deaths each year
• Poor diet has the highest impact on the NHS budget – costing £6 billion a year, higher than smoking, alcohol and physical inactivity
• Sustainable Food Trust (2017) study
• For every £1 spent on food, 37p is spent on health and 50p on the environment

Obesity

• The majority of children, youngsters and adults in the UK are not eating a healthy diet
• One in five children start school overweight or obese
• One third of children leave primary school overweight or obese
• Nearly two thirds of adults in the UK are overweight or obese

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Diet related disease

• Type 2 diabetes
• 3.7 million people diagnosed
• 4.7 million people living with the disease
• 12.3 million people at risk
• More than 5 million people will have diabetes by 2025 (if nothing changes)
• Cardiovascular disease
• Decline in recent decades could be reversed by obesity
• Cancer
• One third of cancers related to diet
• Obesity linked with 13 cancers

Types of cancer linked with obesity

Should we eat less red and processed meat?

• Red meat is a source of readily available iron, zinc & vitamin B12

But:

• Red (especially processed) meat linked with:
• Increased risk of cancer
• Possible mechanisms: iron, DNA changes, nitroso compounds
• Increased risk of diabetes
• Possible mechanisms: Saturated fatty acids, advanced glycation end products, branched chain amino acids, iron, nitrates, sodium
• Increased risk of cardiovascular disease

Red and processed meat and cancer�(Wolk, 2017)

Red and processed meat and diabetes and cardiovascular disease

Red and unprocessed meat and mortality

How much meat are we eating�(household purchase)?

How much meat could we eat?

• UK recommendations:
• consumers eating more than 90g a day red and processed meat to reduce to 70g daily
• How much meat is the world population expected to consume in 2050?
• 40kg per person per year (100g/day)
• How much meat would be available per person (for 9 billion people) if meat production is kept at 2000 levels?
• 29kg per person per year (80g/day)
• Livestock as leftovers
• animals living on marginal land and making use of by-products we cannot eat

Compassion in World Farming

• Calls for 50% reduction in consumption of livestock products by 50% in order to:
• Avert damaging environmental impacts and reduce the incidence of certain diet related disease
• Reduce demand for cereal crops and feed for livestock (36% of calories fed to animals, only 12% reach humans)
• to reduce arable land use, water, energy, deforestation, use of pesticides and fertilisers containing N and P
• Help feed a growing world population
• Reduce pressures on wildlife as habitat destruction could be reversed
• Make it more likely to meet Paris climate targets

Change in meat, fish, beans and nuts intake to incorporate Eatwell Guide sugar and fibre guidelines

What is the environmental effect of

reducing red meat intake?

A systematic review of studies shows GHG reductions are possible by switching to different diets

CO₂ eq – reductions

No meat – greatest reductions

Hallström, E., Carlsson-Kanyama, A., and Börjesson, P. (2015). Environmental impact of dietary change: a systematic review. Journal of Cleaner Production, 91(0), 1-11

Systematic review of 63 studies

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Relative differences in GHG emissions (kg CO2eq/capita/year) between current average diets and sustainable dietary patterns.

Aleksandrowicz L, Green R, Joy EJM, Smith P, Haines A (2016) The Impacts of Dietary Change on Greenhouse Gas Emissions, Land Use, Water Use, and Health: A Systematic Review. PLOS ONE 11(11): e0165797. https://doi.org/10.1371/journal.pone.0165797

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0165797

Relative differences in land use (m2/capita/year) between current average diets and sustainable dietary patterns.

Aleksandrowicz L, Green R, Joy EJM, Smith P, Haines A (2016) The Impacts of Dietary Change on Greenhouse Gas Emissions, Land Use, Water Use, and Health: A Systematic Review. PLOS ONE 11(11): e0165797. https://doi.org/10.1371/journal.pone.0165797

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0165797

Relative differences in water use (L/capita/day) between current average diets and sustainable dietary patterns.

Aleksandrowicz L, Green R, Joy EJM, Smith P, Haines A (2016) The Impacts of Dietary Change on Greenhouse Gas Emissions, Land Use, Water Use, and Health: A Systematic Review. PLOS ONE 11(11): e0165797. https://doi.org/10.1371/journal.pone.0165797

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0165797

Real life non-meat diets have lower GHGs than various meat-based diets (UK example)

Scarborough, P., Appleby, P.N., Mizdrak, A., Briggs, A.D.M., Travis, R.C., Bradbury, K.E., and Key, T.J. (2014) Dietary greenhouse gas emissions of meat-eaters, fish-eaters, vegetarians and vegans in the UK. Climatic Change, 125(2), 179-192

�Reducing meat: �Plant-based, vegan & vegetarian diets�

• A healthy plant-based diet
• Maximises whole food nutrient dense plant foods
• Minimises processed foods, oils and animal foods
• Mediterranean diet
• Similar to healthy plant based diet
• Allows small amounts of dairy products, chicken, eggs and meat
• Fish and olive oil encouraged
• Fat not restricted
• Nordic diet
• Similar to Mediterranean diet
• Emphasises rapeseed oil instead of olive oil
• Features seasonal, healthy regional foods (foods locally sourced or traditionally eaten in Scandinavia, e.g. fish, dark rye bread, berries)
• Vegan & vegetarian
• Avoids all animal foods (but vegetarian includes different combinations of eggs, dairy food, seafood)
• Does not require consumption of whole foods
• Does not require restriction of processed foods high in sugar and fat
• May or may not be healthy

Health impacts of reducing meat

• Healthy plant based diets are:
• Lower in energy (calorie) density
• Higher in nutrient density
• More magnesium, potassium, iron, folate, vitamins (except B12), unsaturated fat, fibre, protein
• Nutrient concerns:
• Iron, iodine, calcium, vitamin B12, vitamin D, omega-3 fatty acids
• Healthy plant-based or healthy vegan/vegetarian diets are associated with:
• ↓ BMI/body weight
• ↓blood pressure
• ↓ rates of heart disease
• ↓rates of diabetes
• ↓risk of cancer
• Unhealthy plant-based/vegan/vegetarian diets associated with increased cardiovascular risk

������What can we as individuals do?�What can government do?

What can we do?

• No meat or less meat?
• Cook and eat differently?
• Culture change
• From meat and two veg ➔ two veg with meat
• Composite dishes with less meat and more veg
• Meat free days/meals?
• Eat less but better – high welfare meat
• Eat all parts of the animal/avoid waste

What can government do?

• Develop Sustainable Dietary Guidelines
• Consumption ➔production
• Change subsidies
• Public procurement (schools and hospitals) based on health and sustainability
• Education and information
• Meat tax (based on GHG emissions)?
• Facilitate technological solutions?
• lab based meat; plant proteins

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P Mason& T Lang (2017) �Sustainable Diets �Abingdon: Routledge Earthscan

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