cardiovascular health effects of flavanol rich chocolate

Endothelial dysfunction (ED) is a hallmark for the initial stage of vascular
dysfunction and has been associated with diet-related disorders such as
cardiovascular disease. Oxidative stress can be regarded as a common dominator
in ED as it can decrease the bioavailability of nitric oxide (NO), a major
mediator in relaxation of vascular smooth muscles. Cacao flavanols may have a
positive effect on endothelial cells, by increase in bioavailability of NO. In
the current study we aim to investigate the effects of flavanol rich chocolate
on vascular function, inflammation, oxidative stress and biomarkers of
endothelial dysfunction.

The primary objectives are formulated to investigate the effect of chocolate
flavanols on vascular function, inflammation, oxidative stress and markers of
endothelial function. The effects of both acute consumption and prolonged
consumption will be studied. Our secondary objectives are to investigate if
daily intake of chocolate flavanols for 4 weeks will improve the response to a
high fat/high energy challenge.

The CHOC-study will consist of two parts. Part 1 will comprise an acute
intervention study and part 2 will comprise a 4 week intervention study. Both
studies will be double blind randomized cross-over designs. In the current
study will use chocolate with a high flavanol content (CHF) and Chocolate with
a high flavanol content (CLF).

Part 1: Acute study
In the first part of the study we will include 27 volunteers and evaluate the
acute effects of 70g CHF or CLF consumption. Measures of vascular function and
blood drawing will be performed at baseline and 2 hours after chocolate
consumption This timeframe was chosen, because the effects on vascular function
after chocolate consumption are most pronounced after two hours. The 27
volunteers that will participate in the acute study will also participate in
the 4 week intervention study.

Part 2: Four week intervention
An additional 27 volunteers will be recruited to obtain a total of 44
participants for the second part of the study. In this part we will evaluate
the effect of daily consumption of 70g CHF or CLF for 4 weeks. Measures of
vascular function and blood drawing will be performed in the fasting state
before and after each intervention period. Urine, feces and adipose tissue
samples will be collected in the end of each intervention period. After each
intervention period, volunteers will receive a HF/HE challenge. Postprandial
measurements of vascular function and blood drawing will be performed before
and 3 hours after consumption of the HF/HE shake. This timeframe was chosen,
because previous studies have shown that the effects on vascular function after
a HF/HE challenge are most pronounced after three hours.

In the current study we will study the effect of 70g chocolate with a high
flavanol content (CHF), which contains 2.2% flavanols of which 10.5% are
epicatechins. As a control we will use 70g chocolate with a high flavanol
content (CLF), which contains 0.2% flavanols of which 14% are epicatechins.
Both CHF and CLF will only differ in flavanol content and will yield the same
amount of energy, theobromide, caffeine or potassium

The HF/HE shake will contain 95g of fat with high amounts of monounsaturated
fatty acids (MUFA).

Subjects that will participate in both study parts will invest 22 hours.
Participants that only participate in the second part, will invest 15 hours.

Chocolate consumption will result in an extra daily calorie intake.In order to
prevent this weight gain, a personal dietary consult of approximately 15
minutes will be planned for each individual before start of the study. During
this consult, the participants dietary habits will be discussed and based on
this information, dietitians will advise the participant to refrain from
certain food products in their normal daily habits, in order to compensate.
These food products will comprise energy dense food snacks like biscuits, chips
and desserts. These dietary guidelines will be similar for both intervention
periods for all participants.

During the intervention period, participants need to visit the university
weekly in order to collect their chocolate. During these visits, the weight of
the participants will be measured. If a weight gain or loss (in case of over
compensation) is recorded of >1kg compared to the starting situation, an extra
consult will be planned in order to correct this. If participants increased
>2kg in body weight at the end of the study, they will be referred to a
professional dietician in order to assist them to regain their original body
weight.

The consumption of the HF/HE shake is not expected to be associated with
discomfort. All vascular measurements are non-invasive. Participant will donate
at most 498ml of blood, dispersed over at least 15 weeks. Hb values of each
participant will be measured before the start of the study to be sure that
blood collection will not lead to anemia.