A study to see if men at risk of prostate cancer can increase their levels of lycopene and green tea (ProDiet)

Please note this trial is no longer recruiting patients.

This study is trying to find out if it would be possible to increase the amount of lycopene and green tea in men’s diets and whether the increase would show up in blood tests.

Some studies have suggested that certain things in the diet, such as lycopene which is found mostly in tomatoes, could reduce the risk of prostate cancer. Another substance that has been looked at is green tea.

This study is looking at the possibility of running a large trial in which men at an increased risk of prostate cancer would be asked to make changes to their diet. Researchers call this a feasibility study.

The aims of the study are to

Find out if it would be possible for men to increase the amount of lycopene and green tea they have by taking supplements or making changes to their diet
See if any increases can be seen in blood samples
Learn more about men’s views on changing their diet and preventing cancer

Please note - You cannot volunteer to take part in this study. It is only open to men who have already joined either the ProtecT trial or another study called ProMPT, which is looking at how prostate cancer grows and exploring possible new treatments.

Recruitment

Start 01/10/2009

End 31/03/2010

Phase

Other

Who can enter

You can enter this trial if you

Are a man aged between 50 and 69
Are registered with a GP practice that is involved with this trial
Have already joined the ProtecT trial and you had a PSA of between 2 and 2.95, or a PSA of 3 or more but a biopsy didn’t find any cancer cells, or you have already joined the ProMPT study

You cannot enter this trial if you

Have a PSA of 20 or higher
Are allergic to green tea or anything that contains lycopene, including guava and watermelon
Are taking hormone treatment called finasteride or dutasteride

Trial design

This study is randomised. The men taking part will be put into 1 of 6 study groups. Neither you nor your doctor or nurse can decide which group you are in. Each group will have a different combination of supplements and dietary advice for 6 months. You have one of the following

Green tea capsules
Dummy (placebo) capsules that look the same as the green tea capsules
Advice about drinking green tea

And one of the following

Lycopene capsules
Dummy lycopene capsules
Advice about increasing the amount of lycopene in your diet

A member of the trial team will ask your views about changing your diet and ways of preventing cancer.

Hospital visits

You see a research nurse at the beginning of the trial. They will collect some background information about you, and ask you to fill in a questionnaire about your diet and lifestyle, your feelings and your general health. The nurse will also measure your weight, height and blood pressure. And they will take a small sample of blood.

The study team will contact you between appointments to see how you are getting on with the supplements and any changes to your diet.

After 6 months, you see the nurse again and fill in another questionnaire. You will have more blood tests, including a PSA test.

Each hospital visit will be about half an hour and will take place at either your GP surgery or local hospital.

Side effects

In earlier studies looking at lycopene or green tea, some men had indigestion. Some felt sick or had diarrhoea. But for most men, these side effects were mild. Very occasionally, drinking large amounts of green tea has caused weight loss, breathing problems and difficulty sleeping.

You may have some bruising in the area where you have blood samples taken.