CONSENSUS STATEMENT

J.M. Ordovás (Tufts University, Boston), D. Corella (University of Valencia), A. López-Farré (H. Clínico San Carlos, Madrid), J. López-Miranda (H. Reina Sofía, Córdoba), P. Mata (Fundación Jiménez Díaz, Madrid), A. Sanchez-Villegas (University of Las Palmas), R. Colomer (H. Dr Josep Trueta, Girona), E. Escrich, Monserrat Solana (U. Barcelona), M.A. Gassull (H.U. Germans Trias i Pujol, Badalona), A. Giacosa (IST National Center Institute, Genova), K. Wahle (The Robert Gordon University, Aberdeen), M.I. Covas Planells (IMIM, Barcelona), C. Galli (University of Milano), J. Mataix (University of Granada), M. Servili (Academia Nationale dell’olivo, Spoleto), F. Pérez- Jiménez (H. Reina Sofía, Córdoba), M.T. Clandinin (University of Alberta, Canada), M. Mancini (Universisity of Naples), F. Casimiro-Soriguer (H. Carlos Haya of Málaga), A.Capurso (University of Bari), F. Sánchez-Múniz (U. Complutense, Madrid) and A. Trichopoulou (University of Athens).

Olive Oil and Cardiovascular Diseases

General Points:

The Mediterranean Diet model might incorporate new advances in nutrition, e.g. including new healthy foods, but maintaining:
1. The presence in the daily intake of the most important foods, providing monounsaturated fat, fibre, antioxidants and omega-3: olive oil, integral cereals, legumes, fresh fruits and vegetables, and fish.
2. The preservation of the Mediterranean way for cooking.
3. The timing (pattern) of the meals.

Specific Points:

The Mediterranean Diet, rich in olive oil, has the following identified health benefits:
1. Decreases plasma LDL (Low Density Lipoproteins) cholesterol levels, when replacing a saturated fat-rich diet, and improves the atherogenic LDL:HDL (High Density Lipoproteins) cholesterol ratio.
2. Reduces plasma triglycerides and increases HDL-cholesterol levels as compared with low fat-high carbohydrate diet.
3. Improves post-prandial lipoprotein metabolism.
4. Decreases LDL susceptibility to oxidative modification when replacing a high PUFA diet.
5. Improves endothelial dependent vasodilatation and inflammatory response.
6. Decreases platelet aggregation, postprandial activation of coagulation factor VII and plasma PAI-1 levels.
7. Improves carbohydrate metabolism in patients with Diabetes Type 2.
8. Reduces blood pressure and the risk of hypertension.
9. Does not promote obesity but increases the lypolitic activity in adipose tissue and the UCP2 activity.

Areas to Develop:

In order to gain further understanding and increased recognition of the health benefits of the Mediterranean diet and its main ingredients for the cardiovascular system, the following needs have been identified:
1. To carry out large, well-controlled primary and secondary prevention intervention studies.
2. To understand the specific and differential healthy effects of olive oil micronutrients on atherogenesis.
3. To adapt the Mediterranean pyramid to local foods and to the taste preferences of different populations.
4. To study the impact of the global model of Mediterranean diet (providing high mono fat) on obesity and the metabolic syndrome.
5. To promote the education of the Mediterranean dietary habits in non-Mediterranean countries, especially in children, using new technological tools (i.e., web sites).

Epidemiology of Olive Oil

General Points:

1. Evidence from epidemiological studies relating the Mediterranean diet pattern, and more specifically the consumption of virgin olive oil, with the primary prevention of cardiovascular disease is still limited.
2. There is supporting evidence from the Seven Countries Study associating a Mediterranean diet with low mortality and incidence of cardiovascular diseases. However, case-control studies have been more controversial, but there is some support for the notion that higher olive oil consumption is associated with lower risk of myocardial infarction.
3. Cohort studies are also limited. In this regard, the EPIC study shows that higher adherence to the Mediterranean diet decreases the risk of cardiovascular diseases, but, in this study, the protection could not be attributed to any single dietary component.
4. The current epidemiological evidence suggests that there is a close relationship between Mediterranean diet, olive oil consumption and cardiovascular risk.

Areas to Develop:

1. Despite the enticing evidence published so far, there is need for more compelling evidence.
2. This will come from more case-control, cohort and interventional (i.e., PREDIMED) studies analyzing the relation between olive oil and cardiovascular risk.
3. Moreover, in future studies, it will be essential to distinguish between different types of olive oil (pure, virgin and extra virgin) in analyzing the potential effects of olive oil in cardiovascular disease prevention.

Olive Oil and Cancer

General Points:

1. Total fat is not the key factor in human cancerogenesis, provided that there is a good balance between energy intake and energy expenditure.

2. The source and type of fat play a relevant role in human cancerogenesis

3. Olive and fish oils are associated with a reduction of cancer risk, unlike oils rich in linoleic acid and possibly foods rich in saturated fat

Specific Points:

1. The anticancerogenic effect of olive oil has been demonstrated experimentally in animal models and in human cell lines, both for olive oil and for its individual components, and specifically for oleic acid and non-fatty acid components

2. The potential mechanisms involved in cancer prevention after olive oil consumption are:
a. The modification of the gene response
b. The modulation of the oxidative inflammatory cascade
c. The induction of apoptosis
d. The cell differentiation and proliferation
e. Changes in the structure and function of cell membranes

3. Experimental evidence has been obtained on the beneficial effect of olive oil in different steps of carcinogenesis, including initiation, promotion and progression.

Areas of relevant interest for future research are:

a) Epidemiology: A global analysis of a large data set from Mediterranean Countries on olive oil consumption and cancer risk is recommended.
b) Experimental Research in the following fields:
b1. Specific effects of the different olive oil components on cancer gene expression.
b2. Role of olive oil components on angiogenesis.
b3. Effects on metastatic cascade.
c) Intervention studies in humans, looking particularly at:
– High-risk populations
– Average-risk populations, with particular regard to non-olive oil consumers
– Cancer patients
d) Effects of different types of olive oil (extra virgin versus non-extra virgin olive oil)
e) Specific effects of olive oil versus food patterns including olive oil
f) Research in the agricultural area and production technology
g) Olive oil and health education

Antioxidant Properties of Olive Oil

General Points:

1. There is evidence supporting the notion that the antioxidant content of olive oil contributes in great measure to its global health attributes. However, given the scarcity and controversial nature of the available randomized controlled studies, much more evidence about the in vivo antioxidant activity of olive oil in humans is needed.
2. The diversity in the phenolic content of the olive oils and the presence of other antioxidants in virgin olive oil is one of the distinctive characteristics of each particular type olive oil.
3. Olive oil phenolics are bio-available in humans.

Specific Points:

1. The content of antioxidants in olive oil can be estimated by measurement of:
a. Total phenols
b. Orthodiphenolic phenols
c. Chromatographic evaluation of single phenolic compounds
d. Tocopherols
e. Total antioxidant activity of the phenolic extract

2. The assessment of antioxidant activity of olive oil in vivo can be determined using the following biomarkers:
a. Isoprostanes in urine and/or plasma
b. Circulating oxidized LDL
c. Uninduced conjugated dienes
d. Malondialdehyde
e. OH- fatty acids
f. Lipid peroxides
g. 8-oxo-deoxyguanosine in lymphocytes and urine
h. Total antioxidant capacity (to be defined)
3. In post-prandial studies virgin olive oil was more active reducing oxidative stress and endothelial dysfunction than refined olive oil, which implies a biological activity linked to the minor olive oil components.
4. Olive oil consumption has shown to be inversely associated both with the cognitive decline and overall survival in the ILSA study.

Areas of Relevant Interest for Future Research

1. Carefully controlled studies in selected population groups are needed to increase the solidity of the evidence linking olive oil antioxidant activity with optimal health and disease prevention.
2. Standardization of current technologies for:
a. Antioxidant content of olive oil
b. Biomarkers of oxidation
3. Develop technology for antioxidant content optimization.

4. Improve our knowledge of the relation between antioxidant content, flavour, shelf life and nutritional (health) aspects of olive oil.
5. Educate the consumers about the relationships between antioxidant content, oil stability, flavour and nutritional properties of the different types of commercial olive oils.

Olive Oil and Aging

1. Published evidence shows virgin olive oil, in the context of the Mediterranean Diet, may prevent the age-related cognitive decline and dementia.
2. Current evidence suggests a Mediterranean diet rich in monounsaturated oleic acid and antioxidants is associated with a significant increase in survival and overall longevity.

Overall Conclusions

1. For each one of the areas examined there is enticing evidence supporting the beneficial health effects of olive oil, especially when consumed as part of a traditional Mediterranean Diet.
2. For each of the areas examined there is an urgent need to obtain more solid epidemiological evidence from intervention studies examining disease end-points
3. For each of the areas examined there is need to carry out more mechanistic studies to answer the specific pathways regulated my macro- and micro-nutrient constituents of olive oil. This is currently possible thanks to the dramatic advances of “-omic” technologies, including genomics, transcriptomics, proteomics, lipomics and metabolomics.
4. The use of new education technologies (via Web) should be fostered in order to increase the knowledge and education of the consumer (especially in non-olive oil producing countries) about the benefits of olive oil.
5. The IOOC should serve as a catalyst of multinational/multi-disciplinary research efforts by bringing together investigators interested in olive oil and health and providing opportunities for an exchange of ideas, knowledge and networking to generate funds from national and international organizations.