Crossover study of diets enriched with virgin olive oil, walnuts or almonds. Effects on lipids and other cardiovascular risk markers

ISRCTN ISRCTN68210440
DOI https://doi.org/10.1186/ISRCTN68210440
Secondary identifying numbers INC0706
Submission date
08/11/2010
Registration date
14/12/2010
Last edited
14/12/2010
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Nutritional, Metabolic, Endocrine
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data
Record updated in last year

Plain English summary of protocol

Not provided at time of registration

Contact information

Dr Emilio Ros
Scientific

Hospital Clínic de Barcelona
C/ Villarroel 170
Barcelona
08036
Spain

Phone +34 (0)93 2279383
Email eros@clinic.ub.es

Study information

Study designRandomised crossover nutrional intervention study
Primary study designInterventional
Secondary study designRandomised controlled trial
Study setting(s)Other
Study typeTreatment
Participant information sheet Not available in web format, please use contact details below to request a patient information sheet
Scientific titleEffects of diets enriched with virgin olive oil, walnuts or almonds on lipids and other cardiovascular risk markers: a randomised crossover study
Study acronymONA
Study objectivesVirgin 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(s)The Institutional Review Board of the Hospital Clínic of Barcelona approved on the 21st March 2006 (ref: CEIC 3110-2006)
Health condition(s) or problem(s) studiedNutrition
InterventionIn 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 typeOther
Primary outcome measureEffects of the three diets on the serum lipid profile, with LDL cholesterol changes from baseline
Secondary outcome measures1. 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 study start date10/01/2007
Completion date15/12/2007

Eligibility

Participant type(s)Patient
Age groupAdult
SexBoth
Target number of participants20
Key inclusion criteria1. 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
Key exclusion criteria1. 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
Date of first enrolment10/01/2007
Date of final enrolment15/12/2007

Locations

Countries of recruitment

  • Spain

Study participating centre

Hospital Clínic de Barcelona
Barcelona
08036
Spain

Sponsor information

International Nut and Dried Fruit Foundation (Spain)
Research organisation

c/o Ms. Goretti Guasch
C. Boule 2, 4
Reus
43201
Spain

Phone +34 (0)977 331 416
Email inc@nutfruit.org
Website http://www.nutfruit.org
ROR logo "ROR" https://ror.org/030wfqt16

Funders

Funder type

Research organisation

International Nut and Dried Fruit Foundation (Spain)

No information available

Spanish Ministry of Science and Innovation (Spain) - Instituto de Salud Carlos III (CIBER Fisiopatología de la Obesidad y Nutrición [CIBERobn])

No information available

Results and Publications

Intention to publish date
Individual participant data (IPD) Intention to shareNo
IPD sharing plan summaryNot provided at time of registration
Publication and dissemination planNot provided at time of registration
IPD sharing plan