Brussels. This is where I have just been, as a member of a meeting organised by the European Heart Network. It was an important and disturbing occasion. The EHN is a consortium of European professional non-government organisations concerned with the prevention of heart disease. Its position on nutrition and heart disease is that the main single dietary cause of heart disease is saturated fat – or, to be more precise, the amounts of saturated fat typically contained in industrialised food supplies and thus diets. This position has been mainstream since the 1970s, and is reflected in practically all UN and official national reports on prevention of heart disease.

Our meeting was called to decide how to respond to what is likely to be a highly influential paper, positioned as a consensus statement, coming from a workshop held in Copenhagen last September. This contradicts the mainstream view on saturated fats and heart disease (1).Was our meeting, chaired by Association Council member Philip James, an over-reaction to one paper in a scientific journal? We felt not. First, the authors of the paper include influential scientists. The best-known is Association founder member Walter Willett, the most quoted university-based nutrition scientist in the USA, who is a triumphant campaigner against trans fatty acids. Other heavy-hitters are Arne Astrup, former chair of the International Association for the Study of Obesity, Franz Kok from the University of Wageningen, and Andrew Sinclair from Deakin University, Sydney. Second, and perhaps related, there was news that the findings of the Copenhagen group were already being massaged and amplified by the meat and dairy industries. Media releases with headlines to the effect of 'Meat, milk and butter good for heart health after all, top scientists prove' seemed to be on the cards. Third, we noted the declared connections between a number of the authors and sectors of industry whose products contain a lot of saturated fat. Muddy water this, because these days it's hard to find any research scientist well-furbished with grants who does not accept funding or any other support from industry whose interests conflict with those of public health.

Fourth, we felt that the timing of what some of us at least felt is a maverick document, published as it is in the run-up to the UN Summit this September on the global prevention of chronic diseases including heart disease, is deliberate. There will be many powerful people in government and industry in New York for the Summit, who in this business-friendly world will want to take the heat off saturated fats. Some of them will be delighted to discredit mainstream nutrition science, in favour of 'public-private partnerships' including interested industry, generating recommendations that suit the policies and profits of the giant manufacturers of processed products.

Deep and muddy water

Here, we are in deep as well as muddy water. As recently indicated in a UN report on dietary fats and human nutrition (2), the story on saturated fats is now, to use a favourite word of policy-makers wondering whether a U-turn is imminent, more 'nuanced' than it was five or ten years ago. It is agreed that not all saturated fats are equally problematic. It is also mainstream now that essential unsaturated oils are in short supply in industrialised food supplies – this was considered a maverick view not so long ago. Most scientists now agreed that trans fatty acids are much worse for heart health than saturated fats – although this view is strongly contested by others.

And there is yet another perspective, exemplified by Carlos Monteiro's latest commentary in World Nutrition. This is that the public health focus always should have been, and still needs to be, primarily on hydrogenated oils (the product of food technology) as distinct from saturated fat (the chemical constituent). Hydrogenation turns unsaturated oils into saturated fats, of course, but the point being made is that the finger should point more at products like hard margarines, baked goods, French fries (chips), and fatty 'long-life' packaged snacks.

That's a lot to take on board. All this, I feel, vindicates the decision of the Association that our website, and WN, should be places for discussion and debate, including of difficult issues. Somebody once told me that nothing worthwhile is easy....

My view

Here is my opinion, and like any other on the topic of dietary fats and public health, it has to be provisional. Number one. The increase in energy-density of food systems, consequent on industrialisation, is a prime cause of overweight and obesity, with what this implies for chronic diseases. Number two. Hard fats are certainly a cause, and probably the main single dietary cause, of heart disease. This may be in part an indirect effect, because they displace unsaturated oils. The issue may be more hardened fats than naturally hard fats – and industrial production of animals makes their fat harder, too. The evidence on trans fats is impressive. But none of this adds up to a rational judgement that saturated fats are harmless. Some colleagues don't agree, but they are in a small minority, even if a force is with them now.

Globally the almost universally agreed recommendation, which continues to be upheld, is that less than 10 per cent of dietary energy should come from saturated fat. But in virtually every country in the world, saturated fat intake is increasing, and so are rates of obesity, diabetes and heart disease. Recommendations at global, national and personal level should be to keep saturated fat intake as low as possible, not to let it drift up to 10 per cent. A low fat diet is very likely to be a plant-based diet.

Public health approaches should always see the bigger picture. My number three point is the one I want to stress. There is one simple message that shines through all this complexity. Let's all of us advocate food systems that stress the central importance of fresh and minimally processed food, and that are plant-based. Even at a time when the literature is complex and contested, the art of public health tells me that I should be saying, do not consume more milk or meat or dairy or meat products. My Indian colleagues may argue that there is merit in impoverished communities, and especially women, drinking a little more milk, but the levels are very low, and the rest of the diets in such communities is virtually all from plant sources.

I have been a lacto-ovo vegetarian since 1985, while also occasionally eating fish. Am I biased in what I say here? Perhaps. Read this with caution, just as you should read the Copenhagen consensus paper with caution. Also, I am a member of the Council of the International Society for Developmental Origins of Health and Disease (DOHaD), whose position paper addressed to the UN Summit this September is published in World Nutrition this month and prefaced on this month's home page.

References

1. Astrup A, Dyerberg J, Elwood P, Hermansen K, Hu F, Jacobsen M, Kok F et al. The role of reducing intakes of saturated fat in the prevention of cardiovascular disease: where does the evidence stand in 2010? American Journal of Clinical Nutrition Accessible at 10.3945/ajcn.110.004622
2. Food and Agriculture Organization of the United Nations. Fat and Oils in Human Nutrition. Report of an expert consultation. FAO food and nutrition paper 91. Rome: FAO, 2010.