1 2 Can rapeseed oil replace olive oil as part of a Mediterranean - style diet ? 3 4

26 This narrative review compares evidence from experimental, epidemiological and 27 clinical studies of the health benefits of rapeseed (Canola) oil and olive oil in order to 28 assess if rapeseed oil is suitable as a sustainable alternative to olive oil as part of a 29 Mediterranean-style diet in countries where olive trees do not grow. From 30 epidemiological studies, the evidence for cardiovascular protection by extra virgin 31 olive oil is "convincing", and for cancers "limited-suggestive", especially oestrogen 32 receptor negative breast cancer, but more studies are required in relation to cognitive 33 impairment. Evidence for rapeseed oil is limited to short term studies on biomarker 34 risk factors for cardiovascular disease. Any benefits of rapeseed oil are likely to be due 35 to α-linolenic acid, but this is prone to oxidation during frying. We conclude that due 36 to a lack of evidence from observational or intervention studies indicating that 37 rapeseed oil has comparable health benefits to extra virgin olive oil, rapeseed oil 38 cannot currently be recommended as a suitable substitute for extra virgin olive oil as 39 part of a Mediterranean-style diet. 40 41 Abbreviations 42 MD Mediterranean diet 43 EVOO extra virgin olive oil 44 OO either virgin or non-virgin olive oil (not specified) 45 RO rapeseed (Canola) oil 46 ALA α-linolenic acid 47 TFA trans fatty acid 48 UFA unsaturated fatty acid 49 50 Introduction 51 The traditional Mediterranean diet (MD) is widely recognised as one of the healthiest 52 in the world, and it is likely that more widespread adoption of this diet in non53 Mediterranean countries would lead to a significant reduction in the incidence of many 54 chronic diseases. Some health organisations in non-Mediterranean countries now 55 recommend a MD. For example, in the UK a MD is recommended by NICE (National 56