Reducing consumption of red and processed meat could make a major contribution to cutting greenhouse gas emissions

If people living in the UK reduced their consumption of red and processed meat to the amount eaten by the bottom fifth of the population, greenhouse gas emissions would be reduced by the equivalent of 28 million tonnes of carbon dioxide every year - and more than 70,000 of the life years lost to ill health every year in the UK could be averted.  This research was published in the BMJ Open.

Consumption of red and processed meat is a leading contributor to greenhouse gas emissions and high intakes of these foods increase the risks of several leading chronic diseases.  In an effort to find a reasonable solution that doesn’t require individuals to cut out red and processed meat entirely, researchers analysed the impact on the incidence of various diseases and the UK carbon footprint if people simply reduced their consumption.

Dr Louise Aston from the University of Cambridge’s Institute of Public Health said: “Reduced consumption of red and processed meat would bring multiple benefits to health and the environment. However rather than investigate the impact on health and greenhouse gases if we all gave these foods up entirely, which we felt to be an unfeasible goal, we took a more realistic approach. We estimated what would happen if the whole population adopted the diet of the fifth with the lowest red and processed meat consumption, which is an obtainable goal since a large proportion of the population are already eating these lower amounts.”

Using newly-derived estimates of meat consumption in the UK from the National Diet and Nutrition Survey of British Adults, the Cambridge researchers were able to assess potential co-benefits to health and the climate from reduced red and processed meat consumption. Survey respondents were divided into fifths by the amount of red and processed meat they consumed, with vegetarians constituting a sixth group.  Although the dietary intake data was collected in 2000/1, results from 2008/9 indicate that intakes are similar or a little higher today.  This means that, if anything, the estimates of consumption and effect are underestimates.

Over a seven day period, the top fifth of males reported consuming 137g (4.83 ounces) per day of red and processed meat, with women consuming 88g (3.10 ounces) per day.  In the bottom fifth, males consumed 56g (1.98 ounces) and women consumed 34 g (1.20 ounces) per day.   The top fifth therefore consumed 2.5 times the amount of red and processed meat as the bottom fifth.  Interestingly, people declaring themselves to be vegetarians reported eating an average of 12 grams for males and 5 grams for women of red or processed meat every day. (Processed meat included smoked, cured, salted, etc.  Red meat included beef and pork.)

The researchers then calculated what the impact would be if the top four groups adopted the consumption of the bottom fifth (and if the proportion of vegetarians in the population, which make up 2% of men and 6% of women, doubled).

Greenhouse gases

Food and drink account for around one-third of total greenhouse gas emissions attributable to UK consumers. Livestock products are particularly greenhouse gas intensive and account for 18 per cent of total global greenhouse gas emissions.

The researchers estimated that if all meat eating individuals reduced their red and processed meat consumption to that of the lowest fifth of consumers, and the proportion of vegetarians in the population doubled, the expected population-wide reduction in greenhouse gas emissions would be 0.45 tonnes CO₂ equivalents per person per year – about 3% of the current estimated total emissions attributable to an individual in the UK.  The total reduction across the UK population would be 27.8 million tonnes per year (based on the 2009 UK population of 61,792,000). For comparison the carbon footprint of the entire NHS in England in 2010 has been estimated to be 20 million tonnes per year.

Disease

Because high intakes of red and processed meats increase the risks of several leading chronic diseases, they found that reduction of intake to the level of the bottom fifth would reduce incidence of coronary heart disease, diabetes and colorectal cancer by between 3 and 12% for the various conditions through the reductions in red or processed meat, or the combined effect of these changes. The researchers estimate that this single dietary change could reduce the total number of life years lost to ill health in the UK by almost 1 per cent.  (Please note that the numbers used by the academics in this estimation were based on 2004 figures).

Specifically, they found that the average risk of diabetes for an adult in the UK would be reduced by 3.2% for females and 4.9% for males just through the reduction in processed meat, and the average risk of colorectal cancer would reduce by 12.2% in males and 7.7% in females through the combined effect of the reductions in both types of meat.

Dr James Smith from the University of Cambridge’s Institute of Public Health said:

“Our research shows that, in the UK, if high consumers of red and processed meat were to adopt the dietary patterns of current low consumers, it could have significant effects on their health.  In reality the benefits might be even greater as we did not calculate impact on other important conditions such as stroke which would also be expected to fall.”

Dr Louise Aston added: “Reducing red and processed meat consumption will bring health benefits to individuals who make the changes, in addition to bringing long-term benefits to the health of the global population through climate change mitigation.  We conclude that dietary recommendations should no longer be based on direct health effects alone.”