The food system is a major contributor to greenhouse gas emissions, with food supply thought to account for some 19 per cent of the UK’s emissions. Meat and dairy are thought to account for 40 per cent of food related emissions.
Joe Millward and Tara Garnett of the University of Surrey, Guildford, say reductions in intakes of meat and dairy products are an “inevitable policy option”. Meat and dairy products currently account for about 25 per cent of daily energy intakes between them. Current intakes of meat and meat products are around 204g per day for men and 135g per day for women.
For the paper presented at the Summer Meeting of the Nutrition Society in Guildford, UK, last June and published in the February edition of the Proceedings of the Nutrition Society, Millward and Garnett looked at how intakes of certain nutrients would be affected by reducing meat and dairy consumption.
The found that reducing meat consumption to a maximum of 70g per day of red and processed meat would be unlikely to affect iron status in functional terms. But protein intake levels for the elderly could be less than is currently advised. The reference nutrition intake (RNI) level for 50+ men is 53.3g per day, and for women 46.5g per day.
Zinc intake levels would also be likely to fall, but whether this could be detrimental to health is uncertain and controversial. Questions about the potential impact on child development are currently “unanswerable”.
People with low milk and dairy intakes generally show low intakes and poor status for calcium, iodine, vitamin B12 and riboflavin, which could be especially problematic for young children and pregnant women.
“Taken together it would appear that the reductions in meat and dairy foods, which are necessary to limit environmental damage, do pose serious nutritional challenges for some key nutrients,” wrote Millward and Garnett.
“These challenges can be met, however, by improved public health advice on alternative dietary sources and by increasing food fortification”.
To fortify or not to fortify?
The researchers point out however that fortification, although it has been embraced in many countries, is controversial. This has been demonstrated in the UK in the recent hot debate about fortifying bakery products with folic acid, an approach employed in the US and elsewhere in the Americas to reduce incidence of neural tube defects in babies – but which some research suggests could increase the risk of colorectal cancer and mask dementia in the elderly.
“Clearly… food fortification can be associated with risk,” wrote Millward and Garnett, “but such risks will have to be balanced against the increasing risk posed by climate change. Policy makers will be faced with tough choices.”
Proceedings of the Nutrition Society, Volume 69, Issue 01, February 2010, pp 103-118
Conference on ‘Over- and Undernutrition: Challenges and approaches’; Plenary Lecture 3 Food and the planet: nutritional dilemmas of greenhouse gas emission reductions through reduced intakes of meat and dairy foods
Authors: D. Joe Millward and Tara Garnett