Clinical trial NCT02449590: Onion, Cardiovascular Risk Markers and Gene Expression
Official title: The Effects of Onion on Plasma Lipoproteins, Blood Pressure and Gene Expression in Overweight Humans - a Double-blinded, Randomized Cross-over Study
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Blood Pressure
Coagulation Delay
Keywords: Onion
Cardiovascular disease
metabolomics
Gene expression
Biomarker
Lead sponsor: University of Copenhagen
Sponsor class: OTHER
Collaborators: name: Instituto De Frio
name: University of Copenhagen
First posted: 2015-05-20
Enrollment: 10
Sex: ALL
Minimum age (years): 18
Maximum age (years): 70
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: PREVENTION

Brief summary: AIMS:

The aims are to investigate whether:

* Increased intake of onion (powder) affects plasma lipid profile, blood pressure, indices of insulin sensitivity and blood coagulation.
* Increased intake of onion (powder) affects the expression/activity of enzymes in the defence against foreign substances, e.g. reactive oxygen species, and whether polymorphisms in some of the involved genes may modulate the effect.
* Polymorphisms involved in the metabolism/effect of bioactive components in onion modulate the excretion of metabolites or modulate some of the outcome variables in the study.

Other aims are to try to identify biomarkers for onion consumption in plasma, urine and feces and to investigate whether onion affects the secretion of fat and bile acids.

HYPOTHESES:

The investigators hypothesize that:

* 2 weeks of increased onion intake will improve the plasma lipid profile
* 2 weeks of increased onion intake will increase the metabolism of potentially harmful substances (such as ROS and free radicals) through a change in the expression or activity of certain enzymes.
* That these effects are modulated by common gene variants (polymorphisms)

Detailed description: In a randomized controlled crossover design, participants will receive 2 daily meals with or without onion powder for 2 weeks. Between the two 2-week period is a 4-week wash-out period. One week before and during each intervention period, the participants will be instructed to avoid consumption of onion, garlic and all foodstuffs containing the same bioactive components (polyphenols, sulfur-molecules)as in onion. This includes a number of vegetables and fruits, condiments, tea, chocolate, red wine etc.

Fasting blood samples will be drawn before and after (on 2 separate days) each intervention period, where also weight and blood pressure are measured.

Participants will collect 24-hour urine and feces samples twice before and at completion of each intervention period.

After the fasting blood sampling on the first blood sampling day in each period, participants will receive a test meal (with 10 g onion powder or placebo, i.e. 8.5 g sucrose+ 2 g soy protein isolate). The acute effects will be studied by blood sampling and urine sampling 0, 2, 4 and 24 hours after the test meal.

Eligibility criteria: Inclusion Criteria:

* Healthy
* BMI 25-40
* No daily medication (except thyroid hormone, stomach acid lowering drugs, mild blood pressure lowering drugs and anti-depressants)
* Not strenuous exercise \>10 hours/week
* No blood donation 3 months before or during the study

Exclusion Criteria:

* Diabetes, CVD, hepatitis, HIV/AIDS
* Cancer or cancer treatment within last 6 months
* Smoking
* Simultaneous participation in other research projects

Primary outcomes:
measure: Change in blood pressure from baseline to two weeks
timeFrame: baseline to two weeks
Secondary outcomes:
measure: Change in waist-to-hip circumference ratio
timeFrame: Change from baseline to two weeks
measure: Change in fecal microbiota profile
timeFrame: change from baseline to two weeks
measure: Change in total cholesterol
timeFrame: change from baseline to 2, 4, and 24 hours and 2 weeks
measure: Change in HDL cholesterol
timeFrame: change from baseline to 2, 4, and 24 hours and 2 weeks
measure: Change in plasma triacylglycerides
timeFrame: change from baseline to 2, 4, and 24 hours and 2 weeks
measure: Change in blood coagulation parameters
timeFrame: 0-4 hours
measure: Change in whole-blood hematocrit
timeFrame: 0-14 days
measure: Change in whole-blood haemoglobin concentration
timeFrame: 0-14 days
measure: Change in body weight
timeFrame: 0-14 days
measure: Change in serum VCAM-1
timeFrame: 0-14 days
measure: Change in serum IL-6
timeFrame: 0-14 days
measure: Change in serum TNF-alpha
timeFrame: 0-14 days
measure: Change in faecal metabolic profiles
timeFrame: 0-14 days
measure: Change in faecal pH
timeFrame: 0-14 days
measure: Change in faecal bile acids
timeFrame: 0-14 days
measure: Change in urine metabolomic profiles
timeFrame: 0-14 days
measure: Change in urine pH
timeFrame: 0-14 days
measure: Change in plasma insulin (multivariate ANOVA)
timeFrame: 0-14 days
measure: Change in plasma glucose (multivariate ANOVA)
timeFrame: 0-14 days
measure: Change in HOMA
timeFrame: 0-14 days
measure: Change in ISI240 (Matsuda insulin sensitivity index 0-240)
timeFrame: 0-240 minutes
measure: Change in erythrocyte Glutathione Reductase
timeFrame: 0-2 weeks
measure: Change in erythrocyte superoxide dismutase
timeFrame: 0-2 weeks
measure: Change in erythrocyte catalase
timeFrame: 0-2 weeks
measure: Change in erythrocyte glutathione peroxidase
timeFrame: 0-2 weeks
measure: Change in plasma untargeted metabolic profile
timeFrame: 0-2 weeks
measure: Change from baseline in leucocyte gene expression profile
timeFrame: 0, 2, 4 and 24 hours and 2 weeks
Other outcomes:
Locations:
city: Frederiksberg C
country: Denmark
facility: Dep. Human Nutrition, LIFE, University of Copenhagen
city: Frederiksberg C
country: Denmark
facility: Department of Nutrition, Exercise and Sports, University of Copenhagen
Study officials:
affiliation: Dep Nutrition, Exercise and Sports, University of Copenhagen
name: Lars O Dragsted, PhD
role: PRINCIPAL_INVESTIGATOR
affiliation: Dep Human Nutrition, LIFE, University of Copenhagen
name: Susanne G Bügel, PhD
role: STUDY_DIRECTOR
References: