Scientists question the link between fatty acids and heart disease

It’s common sense, right? If you eat foods rich in fatty acids, you’re gonna have some heart problems. Not so fast – scientists say. New research finds that the current level of evidence does not support guidelines restricting saturated fatty acid consumption.

Challenging the norm

Image Credit: © eelnosiva / Fotolia

An international research team led by the University of Cambridge analyzed the many existing studies on the health effects of fatty acids. They showed that not only is there not enough evidence to clearly say that fatty acids are linked to health diseases, but there is also very little evidence that high consumption of polyunsaturated fats (ie omega 3 and omega 6) reduce the risk of coronary disease.

But wait, it gets even better – they claim that some of the most basic health recommendations are flawed, or at the very least, don’t have enough substantial evidence behind them. When they analyzed specific fatty acid subtypes (for example different types of omega 3), they found that the effects on cardiovascular diseases also varied greatly – within the same family. This casts a big question mark on dietary recommendations that focus principally on the total amount of fat from saturated or unsaturated rather than the food sources of the fatty acid subtypes.

“These are interesting results that potentially stimulate new lines of scientific inquiry and encourage careful reappraisal of our current nutritional guidelines.”, said Dr Rajiv Chowdhury, the lead author of the research at the University of Cambridge. “Cardiovascular disease, in which the principal manifestation is coronary heart disease, remains the single leading cause of death and disability worldwide. In 2008, more than 17 million people died from a cardiovascular cause globally. With so many affected by this illness, it is critical to have appropriate prevention guidelines which are informed by the best available scientific evidence.”

A fat study

The Cambridge team analyzed data from 72 unique studies with a total of 600,000 participants from 18 nations. It didn’t take long before patterns started to form. First of all, they found out that total saturated fatty acid, wherever you measure it, be it in the diet or in the bloodstream as a biomarker, was not associated with coronary disease risk in the observational studies – and that’s huge. Furthermore, they showed that the consumption of total monounsaturated fatty acids like omega-3 and omega-6 also held no influence on cardiovascular risk.

Professor Jeremy Pearson, Associate Medical Director at the British Heart Foundation, which helped fund the study, said:

“This analysis of existing data suggests there isn’t enough evidence to say that a diet rich in polyunsaturated fats but low in saturated fats reduces the risk of cardiovascular disease. But large scale clinical studies are needed, as these researchers recommend, before making a conclusive judgement.”

The way you should take this study isn’t “Hey, fatty acids are ok, let’s eat’em as much as possible!” – not in the least. They may very well be bad for your heart, it’s just that there’s no conclusive evidence at the moment.

“Alongside taking any necessary medication, the best way to stay heart healthy is to stop smoking, stay active, and ensure our whole diet is healthy — and this means considering not only the fats in our diet but also our intake of salt, sugar and fruit and vegetables.”, Pearson concludes.

Journal Reference:

  1. Rajiv Chowdhury, Samantha Warnakula, Setor Kunutsor, Francesca Crowe, Heather A. Ward, Laura Johnson, Oscar H. Franco, Adam S. Butterworth, Nita G. Forouhi, Simon G. Thompson, Kay-Tee Khaw, Dariush Mozaffarian, John Danesh, Emanuele Di Angelantonio. Association of Dietary, Circulating, and Supplement Fatty Acids With Coronary RiskAnnals of Internal Medicine, 2014; 160 (6): 398-406 DOI: 10.7326/M13-1788

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