Contact information
Type
Scientific
Primary contact
Dr Emilio Ros
ORCID ID
Contact details
Hospital Clínic de Barcelona
C/ Villarroel 170
Barcelona
08036
Spain
+34 (0)93 2279383
eros@clinic.ub.es
Additional identifiers
EudraCT number
ClinicalTrials.gov number
Protocol/serial number
INC0706
Study information
Scientific title
Effects of diets enriched with virgin olive oil, walnuts or almonds on lipids and other cardiovascular risk markers: a randomised crossover study
Acronym
ONA
Study hypothesis
Virgin olive oil and nuts are basic components of the Mediterranean diet, a heart-healthy dietary pattern. Nuts have well known cholesterol lowering effects, while evidence is unclear for virgin olive oil. We designed a study in hypercholesterolemic patients to assess the effects on serum lipids and other intermediate markers of cardiovascular risk of replacing 40% of the fat in the background diet with virgin olive oil, walnuts or almonds. Our hypothesis is that daily intake of virgin olive oil will be associated with low density lipoprotein (LDL) cholesterol lowering to a similar extent than walnuts and almonds consumed at similar doses as percent of total energy.
Ethics approval
The Institutional Review Board of the Hospital Clínic of Barcelona approved on the 21st March 2006 (ref: CEIC 3110-2006)
Study design
Randomised crossover nutrional intervention study
Primary study design
Interventional
Secondary study design
Randomised controlled trial
Trial setting
Other
Trial type
Treatment
Patient information sheet
Not available in web format, please use contact details below to request a patient information sheet
Condition
Nutrition
Intervention
In participants following a background Mediterranean-type isocaloric diet with similar energy, total fat and saturated fat content will be allocated to 3 random sequential periods lasting 4 weeks each in which 40% of energy (25% of fat) is replaced by virgin olive oil, walnuts or almonds.
1. Virgin olive oil is provided in 0.5 litre units sufficient to cover daily allowances of 35 to 50 g, depending on total energy requirements
2. Raw, shelled Spanish almonds (Marcona variety) provided in pre-packaged daily allowances from 50 to 75 g (almonds)
3. Spanish-grown walnuts (Serr/Chandler variety) from 40 to 65 g
No washout necessary between arms because after a dietary intervention is terminated serum lipid changes stabilise in less than 3 weeks. Duration of the study for all participants is 16 weeks.
Intervention type
Other
Phase
Not Applicable
Drug names
Primary outcome measures
Effects of the three diets on the serum lipid profile, with LDL cholesterol changes from baseline
Secondary outcome measures
1. Medical records, including anthropometric measurements (height, weight and waist circumference) and blood pressure at baseline and end of each diet period
2. Food, energy and nutrient intake assessed by 7-day food records at the end of each diet period
3. Plasma fatty acid proportions (as objective measure of compliance); concentrations of noncholesterol sterols, high-sensitivity C-reactive protein, homocysteine, oxidized LDL, ICAM-1, and VCAM-1; and in vitro LDL oxidizability assay to determine lag time of conjugated diene formation at baseline and end of each diet period
Overall trial start date
10/01/2007
Overall trial end date
15/12/2007
Reason abandoned
Eligibility
Participant inclusion criteria
1. Asymptomatic men and women with moderate hypercholesterolemia, age 25 to 75 years (after menopause in women)
2. Serum LDL cholesterol more than 3.36 mmol/L
3. Triglycerides less than 2.82 mmol/L
4. Absence of chronic illnesses or secondary hypercholesterolemia
5. No known allergy to nuts
6. Participants can be under stable lipid-lowering drug treatment (statins or fibrates, statins at doses of no more than simvastatin 40 mg/day or equivalent)
7. Written informed consent
Participant type
Patient
Age group
Adult
Gender
Both
Target number of participants
20
Participant exclusion criteria
1. Subjects on a weight-losing diet
2. Familial hypercholesterolemia
3. Established type 2 diabetes
4. Fatty food intolerance
5. Consumption of products that can influence cholesterol metabolism (other than statins and fibrates), such as resins, ezetimibe, psyllium, fish oil concentrates, soy lecithin, or phytoestrogens
Recruitment start date
10/01/2007
Recruitment end date
15/12/2007
Locations
Countries of recruitment
Spain
Trial participating centre
Hospital Clínic de Barcelona
Barcelona
08036
Spain
Sponsor information
Organisation
International Nut and Dried Fruit Foundation (Spain)
Sponsor details
c/o Ms. Goretti Guasch
C. Boule 2
4
Reus
43201
Spain
+34 (0)977 331 416
inc@nutfruit.org
Sponsor type
Research organisation
Website
Funders
Funder type
Research organisation
Funder name
International Nut and Dried Fruit Foundation (Spain)
Alternative name(s)
Funding Body Type
Funding Body Subtype
Location
Funder name
Spanish Ministry of Science and Innovation (Spain) - Instituto de Salud Carlos III (CIBER Fisiopatología de la Obesidad y Nutrición [CIBERobn])
Alternative name(s)
Funding Body Type
Funding Body Subtype
Location
Results and Publications
Publication and dissemination plan
Not provided at time of registration
Intention to publish date
Participant level data
Not provided at time of registration
Results - basic reporting
Publication summary