Prostate cancer and diet - a randomized controlled trial on the effect of a dietary intervention on the quality of life of men and serum nutrient levels in their blood.

Being diagnosed with prostate cancer impacts patients quality of life. Besides
choosing a treatment strategy that suits patients* values and preferences, they
may look for subsequent strategies to cope with their disease. Dietary changes
may serve as a coping strategy as it can give them the feeling of *doing
something* to help or manage their uncertainty and regaining some control over
their disease and their future survivorship.

Primary objective: to improve participants* quality of life, as measured by the
SF-12 general health domain, by actively engaging in a prostate cancer diet.

Secondary objectives:
- To improve participants* feeling of being in control of their disease, as
measured with the Prostate Activation Measure (PAM), by actively engaging in a
prostate cancer diet.
- To measure the effect of a dietary intervention with special grown products
on the serum nutrient concentrations of participants.
- To survey the user behaviour of both participants and their partners when
engaging in a prostate cancer diet.
- To test the infrastructure of greenkeepers in the Westland, producing and
delivering products for a specific, targeted patient population instead of the
general public.

A randomized controlled trial including three groups of prostate cancer
patients who are currently being treated (including active surveillance) or
have been treated for prostate cancer in the past; (1) a control group, (2) a
prostate cancer diet-group, and (3) a VERS+ -group.

The two intervention groups (prostate cancer diet-group and the VERS+ group)
will receive a prostate cancer diet and recipes to cook 4 dinner meals per week
for a period of 3 months, as well as a few suggestions for breakfast and lunch
meals. Furthermore, both groups will receive some coaching on the impact of
healthy eating, and how to change and maintain a healthier lifestyle. In
addition, the VERS+ group will receive the fruit and vegetables for cooking the
meals through a food box.
The control group will be informed about healthy eating as described in the
guideline from *het Voedingscentrum - de Schijf van Vijf*.

Throughout the study period of 3 months, study participants will attend 3
meetings (at baseline (t1), after 3 weeks (t2) and after 3 months (t3)) for
which they will be requested to fill-out quality of life questionnaires and a
food frequency questionnaires upfront. Prior to the three meetings blood will
be drawn (vena puncture). Blood will be drawn during the meetings using finger
prick blood (Dried Blood Spot Technique). Six and 12 months after the start of
the study, participants will receive follow-up questionnaires to see whether
they have been able to continue the dietary changes made during the three month
study intervention period.

The prostate cancer diet is in accordance with the guidelines of *Het
Voedingscentrum* and the World Cancer Research Fund. Participants will have to
invest time and be perseverant in cooking the recipes and adapting a healthier
lifestyle. Participants off all three groups (individual meetings per group)
are invited to attend three meetings which will last between 1-2 hours per
meeting. In anticipation of the meetings, participants are requested to
complete quality of life questionnaires and a food frequency questionnaire.
Prior to the three meetings blood will be drawn (vena puncture). Risk of vena
puncture is negligible, idemque the burden.