Intended for healthcare professionals

News

WHO pulls support from initiative promoting global move to plant based foods

BMJ 2019; 365 doi: https://doi.org/10.1136/bmj.l1700 (Published 09 April 2019) Cite this as: BMJ 2019;365:l1700

Re: WHO pulls support from initiative promoting global move to plant based foods

"[Willett and Rockström] also disagreed with the assertion that their diet would destroy culinary traditions around the world. “Flexibility to adapt to local diets is inherent in the reference dietary targets,” they wrote.

This is untrue. In the first place, the reference targets only allow for a very low intake of starchy root vegetables. In many parts of the world - including among the famously long-lived Okinawans, but also across Africa and those parts of the South Pacific still minimally impacted by dietary transitions to modern diseases - such foods are a major component of the diet.

Perhaps the thinking is that restricting such foods will increase dependence on grains, which they piously hope will be eaten as wholegrains. However, all these populations, as well as the Irish before the potato famine, were able to avoid epidemics of non-communicable diseases before any grains arrived as products of colonisation.

In the second place, whereas modern populations use cooking fats such as lard, ghee, tallow, and coconut oil the plan is to replace these with potentially very high intakes of polyunsaturated oils, despite recent evidence that polyunsaturated vegetable fats are toxic to beneficial intestinal microbes and associated with an increased risk of skin cancers.[1,2,3]

In the third place, some regions are suited to the production of meat and dairy rather than plant crops; the detrimental effects of transitions to plant crops, with loss of topsoil, nutrients, and expense in fossil fuels, means that such transitions are unlikely to be sustainable (it is noteworthy that planetary health considerations in Eat Lancet were post-hoc justifications - the idea of what is a "healthy diet" came first, and not surprisingly, given the preponderance of vegans and vegetarians on the committee, it was a "plant-based" one.

I would have more sympathy with the statement "“We live in a world where more than 820 million people have insufficient food and many more consume low quality diets. Adoption of the dietary targets would greatly improve the nutrition and health status of most people on the planet.” if the authors had not completely undermined it by making their limited rations of animal foods entirely optional. A small increase in animal foods, as the Ethiopian minister pointed out, can make a huge improvement to the lives of children eating plant-based diets due to poverty. Wartime rationing in the UK aimed to put a minimal amount of affordable meat on everyone's table; sectors of the population unable to afford meat before could add it to the menu (wartime wage increases helped too). Civilian death rates declined as a result. Such a system for the developing world seems reasonable. However, it is not clear how eating less meat in, say, the UK or New Zealand puts more meat on the table in Ethiopia. The carbon cost of flying it around the world to the billions of people that need more meat surely rules that out, especially if production in the meat-exporting countries is meant to decrease.

I suggest that people eat whatever animal and plant foods grow near them, and use the whole animal - for example, using fats avoids the increased demand for palm and soy plantations that is an important cause of deforestation. Using offal as a source of micronutrients decreases the need for plant crops with a high water content, and thus a high land use and carbon transport cost per calorie. Feeding the inedible parts of plants to animals allows us to extract more nutrition from plants than we can purely by ourselves. And so on - the traditional way of doing things that was disrupted from the 1970s onwards by the flood of epidemiological scare stories generated in large part from Dr Willett's research, which were never really proven to be true by any experimental intervention, helping to drive a far more wasteful - and unhealthy - approach to cooking, eating and food production.

1] Wan Y, Wang F, Yuan J, et al Effects of dietary fat on gut microbiota and faecal metabolites, and their relationship with cardiometabolic risk factors: a 6-month randomised controlled-feeding trial. Gut Published Online First: 19 February 2019. doi: 10.1136/gutjnl-2018-317609

2] Di Rienzi SC, Jacobson J, Kennedy EA, et al. Resilience of small intestinal beneficial bacteria to the toxicity of soybean oil fatty acids. Elife. 2018;7:e32581. Published 2018 Mar 27. doi:10.7554/eLife.32581

3] Park MK, Li WQ, Qureshi AA, Cho, E. Fat intake and risk of skin cancer in u.s. adults. Cancer Epidemiol Biomarkers Prev. 2018 Jul;27(7):776-782. doi: 10.1158/1055-9965.EPI-17-0762. Epub 2018 Apr 10. http://cebp.aacrjournals.org/content/27/7/776]

Competing interests: No competing interests

09 April 2019
George Henderson
Researcher
Auckland, New Zealand