Researchers recently published the results of a study that examined the benefits of olive oil in lowering cardiovascular disease incidence.
Cardiovascular disease is one of the leading causes of death in Canada with roughly one Canadian dying from heart disease or stroke every seven minutes.1 The Mediterranean diet, comprised of olive oil, nuts, vegetables, fruits, whole grains, and fish, has been shown to reduce the risk of dying from cardiovascular disease.2,3 OIive oil alone has been shown to be beneficial, but data on the benefits of olive oil consumption in reducing the incidence of cardiovascular disease have largely been derived from clinical trials. Few epidemiological or population-based studies have been undertaken. The ATTICA study, carried out in the greater metropolitan area of Athens (Attica) in Greece, was designed to address this gap. The results of the study were published recently in the European Journal of Nutrition.4
The study was initiated in 2001-2002 when 3,042 healthy participants without cardiovascular disease were enrolled, and baseline measurements were made. Information collected at baseline included many parameters such as age, sex, medical history of both participant and family, body mass index (BMI), blood pressure, blood glucose, dietary habits, smoking status, and physical activity. Detailed information was gathered on the consumption of olive oil and other oils and fats. The participants were reexamined in 2011-2012 as part of the 10-year follow-up. A total of 2,583 of the initially enrolled participants were reexamined, and complete, clinically accurate data were obtained for 2020 participants.
The study participants were divided into three groups based on olive oil consumption: the no olive oil group, the mixed-use group (those who consumed olive oil as well as other fats/oils), and the exclusive olive oil group. Analysis of the data revealed a significant association between cardiovascular disease risk and olive oil consumption. Participants in the no olive oil group were 4.2 times more likely to experience a cardiovascular disease-related event compared to the exclusive olive oil group, and those in the mixed-use group were 5.3 times more likely compared to the exclusive olive oil group. Accounting for the effects of all other factors such as age, sex, BMI, or smoking, which could influence cardiovascular disease outcomes, did not affect the results. The group that consumed olive oil exclusively had a 93% lower chance of experiencing a cardiovascular disease event in the 10-year follow-up period compared to the no olive oil group.
The authors measured the levels of a number biomarkers of systemic inflammation to check if olive oil mediated its cardiovascular disease incidence lowering effects by reducing sub-clinical, low-grade inflammation. Of the various biomarkers measured, only fibrinogen levels appeared linked to olive oil mediated reduction of cardiovascular disease risk.
In summary, the results of this study show that the exclusive consumption of olive oil could lower the incidence of cardiovascular disease over the next decade. Additionally, the study found that the benefits of olive oil may include its mediating effects via fibrinogen, a protein that is essential to blood coagulation and is reported to have a pro-inflammatory role in vascular wall disease.5 Importantly, studies indicate that olive oil consumption may reduce fibrinogen levels.6,7 Further studies would be required to delineate the nature of the association between olive oil consumption, fibrinogen levels, and the development of cardiovascular disease. Finally, these results offer insights into how simple dietary interventions can help reduce the chronic disease burden across populations.
Written by Usha B. Nair, Ph.D.
References:
1) Heart Research Institute. Facts about heart disease: Some sobering statistics. http://www.hricanada.org/about-heart-disease/facts-about-heart-disease. Accessed: November 20, 2017.
2) Trichopoulou A, Kouris-Blazos A, Wahlqvist ML, Gnardellis C, Lagiou P, Polychronopoulos E, Vassilakou T, Lipworth L, Trichopoulos D. Diet and overall survival in elderly people. BMJ. 1995 Dec 2;311(7018):1457-60. PubMed PMID: 8520331; PubMed Central PMCID: PMC2543726.
3) Willett WC. The Mediterranean diet: science and practice. Public Health Nutr. 2006 Feb;9(1A):105-10. Review. PubMed PMID: 16512956.
4) Kouli GM, Panagiotakos DB, Kyrou I, Magriplis E, Georgousopoulou EN, Chrysohoou C, Tsigos C, Tousoulis D, Pitsavos C. Olive oil consumption and 10-year (2002-2012) cardiovascular disease incidence: the ATTICA study. Eur J Nutr. 2017 Nov 9. doi: 10.1007/s00394-017-1577-x. [Epub ahead of print] PubMed PMID: 29124386.
5) Davalos D, Akassoglou K. Fibrinogen as a key regulator of inflammation in disease. Semin Immunopathol. 2012 Jan;34(1):43-62. doi: 10.1007/s00281-011-0290-8. Epub 2011 Oct 31. Review. PubMed PMID: 22037947.
6) Oosthuizen W, Vorster HH, Jerling JC, Barnard HC, Smuts CM, Silvis N, Kruger A, Venter CS. Both fish oil and olive oil lowered plasma fibrinogen in women with high baseline fibrinogen levels. Thromb Haemost. 1994 Oct;72(4):557-62. PubMed PMID: 7878632.
7) Delgado-Lista J, Garcia-Rios A, Perez-Martinez P, Lopez-Miranda J, Perez-Jimenez F. Olive oil and haemostasis: platelet function, thrombogenesis and fibrinolysis. Curr Pharm Des. 2011;17(8):778-85. Review. PubMed PMID: 21443486.