Saturated fat debate shows how hard it is to challenge the establishment
Here’s my response – an article just published in the Conversation “Saturated fat debate shows how hard it is to challenge the establishment“.
A few more reactions – I especially found the bit where Prof Sanders states “Sugar does not cause diabetes” remarkable really….
Expert reaction to editorial on saturated fats as published in Open Heart*
Prof Tom Sanders, Head of Diabetes and Nutritional Sciences Division in the School of Medicine at King’s College London, said:
“Dietary guidelines for prevention of cardiovascular are based on the premise that reductions in the mean population serum LDL cholesterol and blood pressure will reduce population risk of CVD (cardiovascular disease).
“This article rubbishes the relationship with saturated fat and CVD, misrepresents the scientific evidence and then goes on to put the blame on sugar. It is beyond reasonable doubt that elevated LDL (low density lipoprotein) cholesterol is a major determinant of risk factor for cardiovascular disease. The saturated fatty acids palmitic, myristic and lauric acids raise LDL cholesterol in increasing order in meta-analysis human experimental studies1. Sugar intake does not affect LDL-cholesterol or blood pressure.
“Diabetes increases risk of CVD but diabetes is not caused by eating sugar. The relative risks of sugar intake with risk of obesity are very modest compared with obesity and physical inactivity. While sugar sweetened beverages contribute to obesity, where intakes are high it’s probably because it is providing extra calories. However, the high consumers of sugar fizzy drinks are young people – not older people who those most at risk of CVD. It is likely that high intake of sugar-sweetened beverages are contributing to obesity rather having direct effects on CVD risk. Refocusing dietary advice on sugar and away from fat modification and reduction is not helpful.
“Large reductions in saturated fatty acid intakes have occurred in the UK and other Western countries over the past 25 years so intakes are now close to guideline amounts (less than 11% energy). This has been achieved by changes in dietary habits (reducing the use of butter/spreads high in saturated fats) and changes in the food supply with unhydrogenated vegetable oils replacing animal fats. The changes have been in parallel with falls in average serum cholesterol levels in the UK, Western Europe, Australasia and the USA2 as well as in CVD incidence.
“In the UK total fat intake has fallen in absolute terms and as a proportion of energy, while sugar intake has remained as a proportion of the energy relatively unchanged (around 21% energy) according to the nationwide surveys (with non-milk extrinsic sugars providing 11-12% energy). The UK has experienced a 55% fall in cardiovascular disease since 19973. Some of this is due to lower blood cholesterol and blood pressure and decreased smoking prevalence despite the increase in obesity and diabetes.
“People eat foods, not nutrients. Dietary advice to avoid fatty meat products, choose reduced fat dairy produce, and to restrict intakes of cakes, biscuits and puddings, which are often both high in saturated fat and sugar, and to select foods containing unsaturated oils such as nuts, fish and vegetable oils remain good sense. Those who fail to learn the lessons of history are likely to repeat its errors.”
Tom Sanders is also a member of the Scientific Advisory Committee of the Global Dairy Platform.
1Sanders TA (2013) Reappraisal of SFA and cardiovascular risk. Proc Nutr Soc, 1-9.
2Sanders TA (2014) Protective effects of dietary PUFA against chronic disease: evidence from epidemiological studies and intervention trials. Proc Nutr Soc 73, 73-79.
3 Bajekal M, Scholes S, Love H, Hawkins N et al. (2012) Analysing recent socioeconomic trends in coronary heart disease mortality in England, 2000-2007: a population modelling study. PLoS Med 9, e1001237.
Prof Brian Ratcliffe, Professor of Nutrition at Robert Gordon University, Aberdeen, said:
“This editorial is a welcome addition to the debate about what is known as the ‘lipid hypothesis’ of the dietary links to cardiovascular diseases. For the last three decades, accumulating evidence has not provided strong support for the dietary recommendations regarding reducing fat and saturated fat intake. DiNicolantonio does not even touch on the evidence which shows that low fat diets (admittedly lower than the current recommendations) have been associated with poor mood and even depression. Many who adhere to dietary dogma have chosen to ignore the uncomfortable facts that did not fit the hypothesis.
“The dietary links with cardiovascular diseases are not easy to tease apart and much of the earlier work that supported the ‘lipid hypothesis’ used relatively crude methods. For example, detailed fractionation of lipoprotein particles was not available for early studies and there was little awareness of the variety of human genotypes with differential responses to dietary changes. Keys was one of the architects of this dietary fat hypothesis but even he recognised that not all saturated fatty acids are the same (embodied in what became known as the Keys’ equations for predicting the effects of fatty acids on blood cholesterol).
“In what is otherwise a useful summary of some of the issues, it seems that DiNicolantonio falls into his own trap by making a simplistic association of the increases in intake of refined carbohydrates and modified corn syrup that have been seen in the USA with the rise in the prevalence of overweight and obesity. The latter has occurred across much of the developed world without such obvious associations with dietary carbohydrate. The most recent Cochrane review concluded that addressing the quality of fat in the diet could reduce cardiovascular events by 14% and perhaps that is worthy of consideration.”