To evaluate whether (I) buttermilk lowers serum LDL-cholesterol concentrations and as such (II) can prevent the serum LDL-cholesterol raising effects of eggs.
ID
Source
Brief title
Condition
- Other condition
Synonym
Health condition
cholesterol metabolisme
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
Measurements will be performed during the run-in period (days 0, 11 and 14) and
during the experimental period (days 56, 95 and 98). The main effects (egg-yolk
and buttermilk consumption) will be calculated as the absolute differences
between values obtained at the end of the experimental (average days 95 and 98)
and run-in (average days 11 and 14) periods. The primary endpoint is the change
in serum LDL-cholesterol concentrations.
Secondary outcome
Secondary endpoints are changes in serum total and HDL cholesterol,
triacylglycerol, apoA-I, apoB and hsCRP concentrations.
In addition, we would like to determine, via DNA analysis, polymorphisms in
genes that play a role in (LDL) cholesterol metabolism, such as genes coding
for the LDL receptor, PCSK9, SRBI, HMG-CoA reductase, ApoB and ApoE.
Background summary
Eggs are a valuable source of lutein. Additionally, it is possible to enrich
eggs with lutein, which creates opportunities to further increase lutein intake
when needed, as has been suggested for subjects suffering from age-related
macula degeneration (AMD). Indeed, we have already shown in our pilot study
(MEC 07-1-127) with healthy volunteers that consumption of lutein-enriched eggs
increased plasma and macular levels of lutein when compared with consumption of
regular eggs. In that study, the lutein-enriched eggs yolks were provided
through boiled eggs or through a beverage based on buttermilk. Both food
matrices caused comparable increases in serum and macular lutein levels.
Interestingly, the results suggested that the boiled eggs increased serum
LDL-cholesterol concentrations as expected, but the egg-yolk enriched
buttermilk beverage did not. This unexpected finding suggests that consumption
of buttermilk influences cholesterol metabolism. However, that study was not
specifically designed to examine the effects of the buttermilk beverage on
serum LDL cholesterol.
Study objective
To evaluate whether (I) buttermilk lowers serum LDL-cholesterol concentrations
and as such (II) can prevent the serum LDL-cholesterol raising effects of eggs.
Study design
A randomized, placebo controlled factorial 2x2 design. The total study duration
will be 14 weeks, consisting of a 2 weeks run-in period and a 12 weeks
experimental period. Subjects will be stratified for age, gender and BMI over
the 4 experimental groups.
Intervention
During the entire study period, volunteers are instructed to consume a diet
according to the Dutch dietary guidelines (35 en% fat (10en% saturated fat),
50-55 en% carbohydrates). During the two weeks run-in period all subjects will
use daily at lunch 100 mL skimmed milk. During the 12 weeks experimental
period, 30 subjects will continue drinking the skimmed milk (control group),
while the second group will consume a low-fat buttermilk, the third group the
skimmed milk enriched with egg-yolk, and the fourth group egg yolk incorporated
into a low-fat buttermilk based beverage. The egg-yolk will be enriched in
lutein. Whole egg consumption (others than provided by us) is not allowed
during the entire study. The egg-yolk containing buttermilk beverage will be
identical as the one used in the earlier study (MEC 07-1-127) and were
well-tolerated, their taste was perfectly accepted and did not cause any side
effects.
Following the experimental period, subjects can decide whether they want to
participate in a DNA research. For this they can choose to donate blood or
saliva.
Study burden and risks
Before the start of the study subjects will be screened to determine
eligibility during two visits of respectively 15 and 10 minutes. During these
visits, body weight, height and blood pressure will be measured. In addition, a
blood sample (3.5 mL at each occasion) is drawn by venapunction. During the
study, subjects will receive a beverage (100 mL), i.e. skimmed milk,
buttermilk, skimmed milk + egg-yolk, or buttermilk + egg-yolk. At days 0, 11,
14, 56, 95 and 98 fasting blood samples will be drawn (6 x 20 mL). Thus, during
the entire study protocol in total 127 mL (2x3.5 mL + 6x20 mLl) blood will be
drawn. Subjects will be asked to fill out a food frequency questionnaire two
times and to keep a study-diary during the entire 14 weeks study period. On
rare occasions, blood sampling might cause bruises or hematoma. Total time
investment for the subjects will be approximately 2 hours and 20 minutes.
In case subjects choose to participate in the DNA research and for this choose
to donate 10 mL blood instead of saliva, total blood collection during the
whole study will be 137 mL.
Universiteitsingel 50
6229 ER, Maastricht
NL
Universiteitsingel 50
6229 ER, Maastricht
NL
Listed location countries
Age
Inclusion criteria
Subjects are asked to fill out a general health questionnaire in between the first and second screening visit. Only healthy subjects will be included. Obviously, the remark healthy only concerns the aspects checked for in the in and exclusion criteria. The inclusion criteria are:
• aged between 18 and 70 years
• fasting serum total cholesterol between 5.5 - 8.0 mmol/L
• fasting plasma glucose <7.0 mmol/L
• BMI between 25 - 30 kg/m2
• non-smoking
• willingness to abstain for the duration of the study from egg consumption
Exclusion criteria
• unstable body weight (weight gain or loss >3 kg in the past 3 months)
• allergic for eggs or egg-rich products
• allergic or intolerant for cow-milk (lactose) based products
• indication for treatment with cholesterol-lowering drugs according to the Dutch Cholesterol Consensus
• use of medication or a diet known to affect serum lipid or glucose metabolism
• active cardiovascular disease (for instance congestive heart failure) or recent (<6 months) event, such as acute myocardial infarction or cerebro-vascular accident
• not willing to stop the consumption of vitamin supplements, fish oil capsules or products rich in plant stanol or sterol esters 3 weeks before the start of the study
• men: consumption of >21 alcohol consumptions a week
• women: consumption of >14 alcohol consumptions a week
• abuse of drugs
• pregnant or breastfeeding women
• participation in another biomedical study within 1 month prior to the screening visit
• having donated blood (as blood donor) within 1 month prior to the screening visit or planning to do so during the study
• impossible or difficult venipuncture as evidenced during the screening visits
Design
Recruitment
Followed up by the following (possibly more current) registration
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Other (possibly less up-to-date) registrations in this register
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In other registers
| Register | ID |
|---|---|
| CCMO | NL33461.068.10 |