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Observations From the Heart

Saturated fat is not the major issue

BMJ 2013; 347 doi: https://doi.org/10.1136/bmj.f6340 (Published 22 October 2013) Cite this as: BMJ 2013;347:f6340

Rapid Response:

Re: Saturated fat is not the major issue

Judging by the UK newspaper headlines this week I think Dr Malhotra and the BMJ have done a disservice to the public debate on nutrition. Just because glycemic load and soft drinks are associated with obesity and type 2 diabetes does not in any way exonerate saturated fat as a cause of disease. Hundreds of experiments have shown that saturated fat elevates LDL cholesterol to a small degree (1) while clinical interventions which replaced saturated fat with large amounts of polyunsaturated fat have reduced events even if there is debate about which polyunsaturated fat is best (2). The Lyon Diet Heart Study was an intervention which, along with many other dietary changes, lowered saturated fat and increased polyunsaturated fat with a rapeseed oil margarine (3. The benefits of a low glycemic load diet on cardiovascular events has not yet been shown as the randomised trials have not been done. Predimed demonstrated that a large amount of virgin olive oil or nuts reduces strokes in the context of a low saturated fat, Mediterranean diet, but did not show that a low fat diet was harmful as none of the diets were low in fat (4).

We need more data before rejecting the saturated fat hypothesis and confusing the public more.

(1)Mensink RP, Zock PL, Kester AD, Katan MB.Effects of dietary fatty acids and carbohydrates on the ratio of serum total to HDL cholesterol and on serum lipids and apolipoproteins: a meta-analysis of 60 controlled trials.Am J Clin Nutr. 2003 May;77(5):1146-55.

(2)Ramsden CE, Hibbeln JR, Majchrzak SF, Davis JM.n-6 fatty acid-specific and mixed polyunsaturate dietary interventions have different effects on CHD risk: a meta-analysis of randomised controlled trials.Br J Nutr. 2010 Dec;104(11):1586-600.

(3)de Lorgeril M, Salen P, Martin JL, Monjaud I, Delaye J, Mamelle NMediterranean diet, traditional risk factors, and the rate of cardiovascular complications after myocardial infarction: final report of the Lyon Diet Heart Study.
Circulation. 1999 Feb 16;99(6):779-85.
(4)
Estruch R, Ros E, Salas-Salvadó J, Covas MI, Corella D, Arós F, Gómez-Gracia E, Ruiz-Gutiérrez V, Fiol M, Lapetra J, Lamuela-Raventos RM, Serra-Majem L, Pintó X, Basora J, Muñoz MA, Sorlí JV, Martínez JA, Martínez-González MA; PREDIMED Study Investigators.Primary prevention of cardiovascular disease with a Mediterranean diet. N Engl J Med. 2013 Apr 4;368(14):1279-90

Competing interests: No competing interests

27 October 2013
Peter Clifton
endocrinologist
University of South Australia
North Terrace, Adelaide SA