Food controversies and supplements for prostate cancer

It's unclear if particular foods can reduce the risk of developing prostate cancer or the risk of prostate cancer coming back.

Research has looked at a number of different foods and supplements. But we still need more research to find out for sure whether any of these can help men with prostate cancer. 

Tomatoes and lycopene

Tomatoes and tomato based foods contain lycopene. There is more in cooked and processed tomato products than fresh tomatoes.

There is no good evidence that lycopene reduces the risk of prostate cancer or stops the cancer coming back. 

Even so, tomatoes, like other fruits and vegetables, can still be part of a healthy balanced diet, which can help to reduce the risk of cancer overall. 

Dairy foods and calcium

Some research has shown that men who have a diet high in calcium may have a higher risk of developing prostate cancer. But other studies haven't found a link.

This means that the evidence that diets high in calcium can reduce the risk of developing prostate cancer is limited. 

You should eat a healthy balanced diet that includes adequate amounts of calcium. Calcium is important for our bodies. It helps keep our bones strong and healthy and our muscles working.

Adults need 700 mg of calcium each day. Most people can get this amount from a balanced healthy diet. Good sources of calcium include dairy foods such as:

• milk
• cheese
• yoghurts

Calcium and hormone therapy

It is particularly important to have adequate amounts of calcium if you are having hormone therapy. This is because bone thinning (osteoporosis) is a side effect of this treatment.

Talk to your doctor or GP if you are struggling to eat a balanced diet and ask whether you need to take supplements. 

UK guidance says that calcium supplements up to a dose of 1,500mg a day do not cause problems. Doses higher than this could cause side effects, such as loose poo (diarrhoea) and stomach pain.

Green tea

Some studies have suggested that green tea might reduce the risk of prostate cancer. But other studies have not shown that green tea reduces the risk of cancer in humans. 

This means that there isn't reliable evidence that shows that green tea prevents prostate cancer. 

Soy

Soy (soya) is in products such as tofu, soya milk, miso and as a supplement.

So far, evidence shows that eating soy products does not affect cancer risk, including prostate cancer.

You can include soy foods in your diet as part of a healthy diet.

Pomegranate

Pomegranate (Punica granatum) is a good source of fibre and vitamins.

There is no reliable evidence that pomegranate can reduce the risk of prostate cancer coming back. This is because studies have shown no benefit from drinking pomegranate juice or taking pomegranate extract. But a small study showed that prostate cancer took longer than normal to progress in men who drank pomegranate juice every day.

Selenium

Selenium is a naturally occurring chemical found in plant foods such as:

• vegetables
• fish and shellfish
• some meats

There is no reliable evidence to say that selenium prevents prostate cancer.

Early research in the laboratory showed that selenium might stop cancer cells from growing. But clinical trials in humans have not produced the same results.  

Multivitamin supplements

There is no strong evidence to say that multivitamin supplements are helpful as a treatment for prostate cancer. Doctors only recommend you take them if you can’t eat a normal diet.

Vitamins and minerals in food are an important part of a healthy balanced diet. They carry out many different roles in the body including:

• bone health
• healing
• helping the immune system to fight infection

Vitamins and minerals are in a variety of foods such as:

• vegetables and fruit
• milk and dairy foods
• eggs
• cereals
• meat and fish
• nuts

Vitamin D

There is no reliable evidence to say that vitamin D supplements can reduce the risk of prostate cancer coming back. But vitamin D is very important for our bodies. So it's important that you:

• eat vitamin D rich foods
• have safe amounts of sunlight
• take the recommended dose of supplements if you are at risk of having low levels

We need vitamin D to absorb calcium. Together they play an important part in keeping bones healthy.  A lack of vitamin D (deficiency) in adults could lead to bone problems, such as osteoporosis.

Vitamin D is very important for men having hormone therapy because of the risk of bone thinning.

We mainly get vitamin D from sunlight and some foods.

Public Health England recommends that in winter and autumn, people in the UK should take a daily supplement of vitamin D containing 10 micrograms. This is because it is difficult for people to get enough vitamin D through their diet.

Some people might not get enough vitamin D from sunlight in summer or winter. So they are advised to take a supplement all year round.

People at particular risk of vitamin D deficiency include those:

• who wear clothes that cover the whole or most of their body
• who are older
• who are housebound
• who deliberately avoid the sun
• with dark skin from African, African-Caribbean and South Asian backgrounds

You get vitamin D in your diet from:

• oily fish such as salmon and sardines
• some fat spreads and cereals
• eggs

Vitamin E

Vitamin E is an antioxidant found in a variety of foods including:

• nuts and seeds
• green leafy vegetables
• vegetable oil

So far, there is no reliable evidence that shows that vitamin E reduces the chances of cancer coming back. Or that it slows the growth of prostate cancer.

The Department of Health and Social Care advise that you should be able to get the amount of vitamin E you need by eating a healthy diet. 

If you take vitamin E supplements, only take 540 mg or less a day. Too much vitamin E can be harmful.

Questions you may want to ask your doctor

• Can I see a dietitian to help me with my diet?
• Can I take multivitamins or other supplements with my prescribed medicine or cancer treatment?