Improving resilience with whole grain wheat

Wheat is a dominating staple food source in the Netherlands and the number of
whole grain wheat (WGW) products is growing rapidly. Intervention studies on
WGW products mainly focused on cholesterol and a few other outcome parameters
of either vascular health or glucose metabolism. However metabolic health is
the result of a complex interplay of different organs. Investigating WGW
effects on only a few parameters will therefore give a simplified picture about
the health effects. In the current study we aim to investigate the effect of
12-week WGW intake on cardiovascular health, glucose metabolism and liver and
adipose tissue health. We will do this by comprehensive phenotyping in the
fasting state and by quantifying metabolic flexibility after a mixed meal
challenge. This approach will provide us with more mechanistic insights on how
WG may affect health and how different organs are affected and work together.
Furthermore there is an increasing number of possibilities for individuals to
map their health status at home. These measures can contribute to health
assessment in the future, but the usability of such devices for scientific
purposes has not been investigated.

Primary objective: To investigate the health benefits of WGW on cardiovascular/
cardio-metabolic health by means of applying a mixed meal challenge. Secondary
objective(s): To investigate the health benefits of WGW on liver- and adipose
tissue health and to evaluate the potential of do-it-yourself (DIY) devices in
quantifying health effects in a nutritional intervention study.

The study is a double blind, parallel trial. Two different treatments will be
evaluated e.g. a 12-week intervention with WGW products (98g of WGW per day)
and a 12-week control intervention with refined wheat (RW) products. A 4-week
run-in period with RW products will be included prior to the intervention. Two
experimental visits will be planned before and two experimental visits will be
planned after the 12-week intervention period. In the first experimental visit
we will determine liver fat and abdominal fat distribution. In the second
experimental visit we will comprehensively phenotype the participants which
will include a response to a mixed meal challenge test.

A twelve week intervention of either 98g whole grain wheat (WGW) or a control
intervention of refined wheat (RW) in the form of 4 slices of bread and 2
servings of ready to eat cereals (RTEC).

The subjects that will participate in this study will invest approximately 26
hours. There are minor risks for the participants. There is no evidence that
the intervention products are unsafe. It is not likely that the intervention
products will induce weight gain or loss, but in order to minimize this effect
we will weigh all subjects each week and will intervene if necessary so that
weight variation is kept at a minimum. Subjects in the RW group will have a
reduced intake of fibre. In our opinion this reduction is minimal, however this
can be more substantial in persons who have a high intake of dietary fibre.
Therefore, we will monitor gastrointestinal discomfort every week. In case of
structural complains we will council our medical supervisor. MRI is a
non-invasive and safe procedure as long as no contraindication is met. The
vascular measures are non-invasive. After the FMD measurement we will determine
endothelium independent dilation by sublingual nitroglycerin administration.
Side-effects of nitroglycerin administration may include headaches and
dizziness. The adipose tissue biopsy can occasionally cause a local hematoma or
bruise and some participants may report pain or discomfort. During the study we
will collect 2x200ml of blood with 12 weeks in between. The Hb value of each
participants will be checked before blood collection and blood collection will
therefore not lead to anaemia. Participants will receive ¤400,- after
completion of the study and will receive a repayment of travel expenses,
receive a warm evening meal the day before a study day and a lunch/breakfast on
each study day.