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Clinical Review

Non-alcoholic fatty liver disease

BMJ 2014; 349 doi: (Published 29 July 2014) Cite this as: BMJ 2014;349:g4596

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The article fails to mention the main causes and most effective treatments for NALFD. This is not surprised because, although well researched, these causes and treatments are not well known. Consumption of vegetable oil, containing omega-6 fatty acids such as linoleic acid, is the most effective way of inducing fatty liver disease [1]. Saturated fats reverse NAFLD and beef fat does this most effectively [2]. Sugar, particularly fructose, also causes NAFLD. Omega-3 fats and medium chain triglycerides are beneficial.

Omega-6 is an essential fatty acid. We need to consume 0.5% of total calories as omega-6. The problem is that in the West we have 10%, which is twenty times as much as is good for [3]. Vegetable oil is widely used in cooking and food processing. Excess omega-6 fats are converted to inflammatory prostaglandins and liver inflammatory changes result. This pathway is inhibited by omega-3 fats. Ideally omega-3 and omega-6 intake should be equal but in the West omega-6 intake is twenty times greater [4]. Heating polyunsaturated omega-6 fats results in toxic oxidation products, which are far worse than the trans fats that vegetable oil has replaced [5], and these may cause further liver damage.

Olive oil is probably almost as bad. It contains 20% linoleic acid when pure and more when nut or vegetable oil is added. This practice is universal to cut the cost of olive oil production [6].

The inclusion of vegetable oil and the reduction of saturated fat continue to be seen as part of a healthy diet. We can therefore expect to see a continuing rise in the incidence of NAFLD.


1. AHS13 Victoria Prince — Fatty Liver: Is It the Fat's Fault?
2. Beef fat prevents alcoholic liver disease in the rat, Alcohol Clin Exp Res. 1989 Feb;13(1):15-9
3. Fish, Omega-3 and Human Health by William Lands
4. Diets could prevent many diseases, William E. M. Lands, Lipids, April 2003, Volume 38, Issue 4, pp 317-321
5. The Big Fat Surprise by Nina Teicholz
6. Extra Virginity by Tom Mueller

Competing interests: No competing interests

03 August 2014
William T Neville
General Practitioner
Abbey Road Surgery, 63 Abbey Road, Waltham Cross, Hertfordshire, EN10 7JQ