With consumption of meat rising annually as human populations grow and affluence increases, a new review paper from the Oxford Martin School examines the implications for human health and the environment, and explores the options policy-makers have should they wish to intervene to affect global diets.

Current total global meat consumption stands at more than 300 million metric tonnes per year, having risen from seven million in 1960, and could rise by as much as 76% by the middle of this century.

Evidence collated in the review suggests that increased consumption of meat, especially red and processed meats, will adversely affect public health, with the strongest evidence pointing to increased risk of colorectal cancer. The environmental impacts of meat production includes loss of forests to create pasture and arable land, increased pressure on water supplies and increased soil erosion.

The review, which was published recently in Science, is supported by the Wellcome Trust’s Our Planet Our Health, is part of the LEAP programme, a major interdisciplinary research partnership in the areas of global food systems and urbanization.

The four-year project - directed by Professor Charles Godfray, Director of the Oxford Martin School and the Oxford Martin Programme on the Future of Food, and Professor Susan Jebb, Professor of Diet and Population Health, Nuffield Department of Primary Care Health Sciences – aims to understand the health, environmental, social and economic effects of meat and dairy consumption, to provide evidence and tools for decision makers to promote healthy and sustainable diets.

Professor Godfray said: “Meat consumption is rising globally and were a majority of the world’s population to consume meat at the rates we do in North America and Europe it is hard to see how agriculture could meet the demand without serious consequences for greenhouse gas emissions, water consumption and food prices (as more and more arable crops are grown for animal food).

“There is evidence that consumption of certain meat types (in particular red meat and processed meat) increases health risks – the best documented is a link between processed meat and colorectal cancer. Reducing consumption of these food types lowers risks from these diseases – however, while the numbers of lives saved at the population level may be significant, the change in risk for an individual may be quite small.”

In the paper, the researchers consider a range of potential government interventions aimed at changing people’s diets, including nutritional labelling and the repositioning of meat options to appear after vegetarian options on restaurant menus. Placing additional taxes on foods based on their saturated fat content or GHG emissions was also explored.

In some high-income countries, per capita meat production is slowing as a result of a complex interaction of different stories and campaigns about the positives and negative of eating meat This is partly helped by an increasingly connected society, the researchers say, but is strongly influenced by different stakeholder groups such as the food industry and campaigning organisations.

Professor Godfray said: “Reducing consumption of these food types lowers risks from these diseases – however, while the numbers of lives saved at the population level may be significant, the change in risk for an individual may be quite small.”

The study also examined people’s justification of meat consumption. This came down to three main categories: situational factors, the environment, and personal characteristics. For example, Inuit communities have no choice but to farm and hunt animals as they are unable to grow produce in the harsh environment of the Arctic. In addition to this, factors such as affordability, availability and convenience along with social and cultural values play a large role in how people view meat consumption, the authors found.

In order to change the consumption habits of the global population, there is need for more evidence about the effectiveness of government interventions, says Professor Godfray: “Governments can affect meat consumption in numerous ways including through a broad range of fiscal measures. An evidence base is growing for the effectiveness of such interventions, though in few countries is there a political consensus for action.”

• Meat consumption, health, and the environment. Charles J. Godfray, Paul Aveyard, Tara Garnett, Jim W. Hall, Timothy J. Key, Jamie Lorimer, Ray T. Pierrehumbert, Peter Scarborough, Marco Springmann, Susan A. Jebb Vol. 361, Issue 6399, eaam5324 DOI: 10.1126/science.aam5324,9,