Two scientific reviews based on large cohort studies offer scientific evidence on the real possibility of preventing cardiovascular disease, heart attacks and strokes by daily consumption of 20-30 g of extra virgin olive oil.
The cohort studies underlying the two papers followed more than 150,000 individuals, in total, on both sides of the Atlantic. To demonstrate how the health benefits of olive oils are also expressed outside the Mediterranean diet.
1) Daily consumption of olive oils and prevention of cardiovascular disease, the IMDEA Food meta-analysis
The Spanish research institute IMDEA Food recently published in the Clinical Nutrition Journal an open-access meta-analysis (Donat-Vargas et al., 2021) examining the correlations between regular olive oil consumption and subclinical atherosclerosis, coronary artery disease, total cardiovascular disease (CVD) risk, and stroke. (1) The scientific review is based on three cohort studies involving, in total, 59,846 individuals.
1.1) Olive oil and subclinical atherosclerosis.
The inverse relationship between daily olive oil intakes and subclinical atherosclerosis conditions was evaluated in the Aragon Workers Health Study(AWHS). Through:
– administration of questionnaires on cardiovascular risk factors (CDV) and lifestyles to 2,617 workers at the Opel factory in Figueruelas (Zaragoza),
– Noninvasive imaging of subclinical atherosclerosis in individuals without CDV disease, in the age group 39-59 years,
– estimated average olive oil consumption (32.8 + 14.3 g/day total, of which extra virgin and virgin oil 20.1 + 20.5 g, olive oil 12.7 + 16.0 g) and the correlations.
1.2) Extra virgin olive oil and cardiovascular events.
In contrast, the SUN(Seguimiento Universidad de Navarra) project followed 18,266 individuals aged 18-91 years, with an average follow-up of 10.8 ± 4 years. Aiming to identify possible interactions between dietary habits and cardiovascular events.
Data were collected semi-annually through semi-quantitative questionnaires on consumption frequencies of 136 foods. The average intake of olive oils was estimated at 18.5 + 14.9 g/day, without distinguishing the levels of extra virgin and virgin olive oil (whose consumption was reported to be prevalent).
1.3) Cardiovascular events, the EPIC study.
The EPIC(European Prospective Investigation into Cancer and Nutrition) cohort study, included 39,393 participants in the age range 29-69 years, in five Spanish regions (Asturias, Granada, Gipuzkoa, Murcia, Navarra), for an average follow-up period of 22.8 years.
Information on habitual food intake, in EPIC, was collected electronically by trained staff through dietary history with recording of quantities of 662 foods and recipes. The average intake for common oil was 16.4 + 15.5 g/d and for virgin oil 3.8 + 10.0 g/d.
1.4) Meta-analysis
IMDEA Food researchers organized the statistical analysis of the AWHS, SUN and EPIC studies through two models:
– base. Age, gender, total energy intake,
– advanced. Education level, smoking (if yes, number of cigarettes), physical activity, BMI, alcohol consumption, dietary fiber, prevalence of dyslipidemia/hypercholesterolemia, hypertension, and diabetes.
Participants in the three studies were then characterized into four categories based on daily olive oil consumption levels (0-10, 10-20, 20-30, >30 g/day).
1.5) Evaluations and conclusions
The scientific review conducted by IMDEA Food, as a result of the above analysis, observes an inverse relationship between regular consumption of olive oil, on the one hand, and the occurrence of cardiovascular disease (CVD) and stroke. The greatest benefit is seen in individuals who consume 20-30 g per day, and the greatest protection is obtained with the consumption of extra virgin, or virgin, olive oil.
Extra-virgin olive oil-as well as virgin olive oil, whose quality parameters are lower (2)-is distinguished from so-called ‘olive oil’ in that it is obtained exclusively from the mechanical pressing of olives. In contrast, so-called ‘olive oil’ is a mixture of virgin and refined (or deodorized) oils. Scientific research has shown that the phenolic compounds (e.g., polyphenols) to which the main health virtues are attributed are present in a higher proportion in organic extra virgin olive oil. (3) Conversely, phytocompounds tend to degrade in refined oils.
2) Replacing various fats with olive oil and reducing premature mortality
Another review science-conducted in the U.S. and just published in the Journal of the American College of Cardiology (Guasch-Ferré et al., 2022)-in turn found that the substitution of about 10 g/die of miscellaneous fat sources (margarine, butter, mayonnaise, dairy fat) with equivalent amounts of olive oil is found to be associated with a lower risk of premature mortality from cardiovascular disease (CDV), cancer, neurodegenerative disease, and respiratory disease. (4)
2.1) Olive oil outside the Mediterranean diet.
‘Most of the information on the health benefits of olive oil has been collected in studies conducted in Mediterranean populations, and little is known about other geographical locations. The research under review (Guasch-Ferré et al., 2022) reports the results of 3 cohort studies to assess olive oil consumption in relation to CVD and partially fills this gap.
This large cohort study of nearly 93,000 individuals and about 9,800 incident CVD cases, after 24 years of follow-up, provides robust evidence of the association between olive oil consumption and cardiovascular disease in a non-Mediterranean country such as the United States.
Results show that compared with participants with the lowest olive oil consumption, those consuming >0.5 tablespoon/day of olive oil had a 14% lower risk of CVD and an 18% lower risk of coronary heart disease (CHD), confirming the results of a recent meta-analysis.’ (5)
2.2) US scientific review
The US science review (Guasch-Ferré et al., 2022) reworks data collected in the Nurses’ Health Study and in the Health Professionals Follow-up Study, of 60,582 women and 31,801 men who were free of cardiovascular disease and cancer in 1990 and were followed for 28 years through a questionnaire every four years.
Consumption of unidentified olive oils has been classified into four categories:
(a) Never or less than once a month,
(b) 0-4.5 g/day (1 teaspoon),
(c) 4.5-7 g/day (up to half a tablespoon),
(d) >7 g/day (more than half a tablespoon). 9 g/day is the average consumption of olive oil in this category (5 percent of the total).
2.3) Reducing the risks of premature mortality
The reduction in risks of premature mortality-between the group of frequent consumers (group ‘d’) and those who do not consume olive oil (group ‘a’) was significant:
– 29% mortality from neurodegenerative diseases,
– 19% mortality from cardiovascular disease,
– 18% mortality from respiratory causes,
– 17% cancer mortality.
These benefits have been recorded, it should be noted, in a population group consuming 7-10 g/d of uncharacterized olive oils. The Food and Drug Administration (FDA), after all, already in 2018 confirmed the scientific substantiation of qualified health claims on the consumption of high oleic acid oils (>70%) and the reduction of CHD(coronary heart disease) risks. (6)
3) Interim Conclusions.
Just consuming less than one tablespoon of olive oil per day has been shown to significantly reduce the risks of the most serious diseases, including chronic and disabling diseases (NCDs, Non Communicable Diseases). (4)
Consumption of one and a half tablespoons of olive oil-better if extra virgin, all the better if organic-is an effective tool in preventing cardiovascular disease, the leading cause of premature mortality everywhere. (1)
Further studies will be able to confirm how organic extra virgin olive oil is a key presidium (3) for protecting organs and functions of the body, as well as the immune system. (7) Due to the presence and integrity of the more than 200 phytocompounds that characterize true natural olive juice.
Dario Dongo, with the collaboration of Isis Consuelo Sanlucar Chirinos
Notes
(1) Donat-Vargas C, Sandoval-Insausti H, Peñalvo JL, Moreno Iribas MC, Amiano P, Bes-Rastrollo M, Molina-Montes E, Moreno-Franco B, Agudo A, Mayo CL, Laclaustra M, De La Fuente Arrillaga C, Chirlaque Lopez MD, Sánchez MJ, Martínez-Gonzalez MA, Pilar GC. Olive oil consumption is associated with a lower risk of cardiovascular disease and stroke. Clin Nutr. 2022 Jan;41(1):122-130. doi: 10.1016/j.clnu.2021.11.002. Epub 2021 Nov 15. PMID: 34872046. Full text accessible at https://www.clinicalnutritionjournal.com/article/S0261-5614(21)00503-3/fulltext
(2) The differences between extra virgin olive oil and virgin olive oil are referred to in the previous article. See also the article https://www.foodagriculturerequirements.com/archivio-notizie/domande-e-risposte/legge-1407-60-confisca-obbligatoria-per-olio-non-evo-risponde-l-avvocato-dario-dongo
(3) Dario Dongo, Andrea Adelmo Della Penna. Organic extra virgin oil, organic olives and health. Polyphenols that matter. GIFT (Great Italian Food Trade). 6/29/21, https://www.greatitalianfoodtrade.it/salute/olio-extravergine-biologico-olive-bio-e-salute-i-polifenoli-che-contano
(4) Guasch-Ferré, M., et al. (2022). Consumption of Olive Oil and Risk of Total and Cause-Specific Mortality Among U.S. Adults. Journal of the American College of Cardiology. doi.org/10.1016/j.jacc.2021.10.041
(5) Ramon Estruch, Rosa M. Lamuela-Raventós, Emilio Ros. (2022). The Bitter Taste of Extra Virgin Olive Oil for a Sweet Long Life. Journal of the American College of Cardiology. doi: 10.1016/j.jacc.2020.02.043 https://www.jacc.org/doi/full/10.1016/j.jacc.2020.02.043
(6) Dario Dongo. Oleic acid and coronary heart disease prevention, green light in USA. GIFT (Great Italian Food Trade). 2.12.18, https://www.greatitalianfoodtrade.it/idee/acido-oleico-e-prevenzione-malattie-coronariche-via-libera-in-usa
(7) Dario Dongo, Andrea Adelmo Della Penna. Organic foods and the immune system, scientific evidence. GIFT(Great Italian Food Trade). 11.4.20, https://www.greatitalianfoodtrade.it/salute/alimenti-biologici-e-sistema-immunitario-evidenze-scientifiche
Dario Dongo, lawyer and journalist, PhD in international food law, founder of WIISE (FARE - GIFT - Food Times) and Égalité.
