Last updated by Dr Sarah Brewer on
Several nutritional approaches can improve – or even prevent – benign prostate enlargement (BPH), and can be used alongside conventional treatment.
Soy isoflavones and prostate health
Soy beans contain oestrogen-like plant hormones (mainly genistein, daidzein and glycitein) which block the proliferation of prostate cells in BPH. Men who follow a traditional Asian diet obtain between 50mg and 100mg isoflavones a day from edamame, tofu, miso etc, and typically have a smaller prostate gland than men following a Western diet who obtain just 2mg to 5mg isoflavones per day.
In a study involving 176 men with BPH who were being managed by ‘watchful waiting’ , those taking 40 mg isoflavones per day showed significant improvements in peak urinary flow rate, bladder emptying and overall general health after 6 months, than the men taking inactive placebo.
Aim to eat at least three servings of soy foods (eg tofu, soy yogurts) per week, and use soy milk regularly (eg with cereals in place of cows’ milk). You can add soy beans to soups, stews, chilli, stir fries, risotto and salads and add soybean protein powder to smoothies and shakes, for example. If you use soy protein powder for shakes, 60g of soy protein provides 45mg isoflavones. Soy isoflavones are also available as food supplements.
Yogurt and prostate health
When following an isoflavone-enriched diet, eat more live Bio yogurt (try soy milk versions) or take probiotic supplements. These contain bacteria that help to convert dietary isoflavones down into their most active forms. Those who possess good amounts of certain beneficial bacteria can also convert the isoflavone, daidzein, to a more powerful oestrogen called equol.
Equol specifically binds to dihydro-testosterone and stops it interacting with its receptors which reduces prostate growth in BPH.
While one in two Japanese males are equol producers, only around one in four western men are equol producers. Researchers suggest that one possible strategy for reducing your risk of prostate disease may be to increase the proportion of equol-producers by boosting the level of beneficial bacteria in your bowel thought dietary alteration. Eating live Bio yogurt and/or taking probiotic supplements to increase the chance of retaining equol-producing bacteria in the gut. This is especially important after taking antibiotics which can dramatically reduce the level of probiotic bacteria present.
Tomatoes and prostate health
Tomatoes contain lycopene, a rich, red pigment which is locked away inside tomato cells. When cooked, they release five times more lycopene than when eating the same tomatoes raw. Tomato ketchup and tomato purée are therefore among the richest dietary sources. As lycopene is fat-soluble, drizzling olive oil over a passata-based pizza also increases your dietary absorption of lycopene as much as threefold.
In a study involving 40 men with BPH, those taking lycopene supplements (15mg per day for six months) reduced the progression of BPH with a reduction in PSA levels, improvement of prostate symptoms, and no significant gland enlargement when measured by trans-rectal ultrasonography and digital rectal examination. In the control group not taking lycopene, the prostate continued to progressively enlarge.
Aim to eat tomatoes on most days, adding them to pasta sauces, stews and soups. Roast tomatoes whenever the oven is on to serve with fish and meats. Lycopene is also found in red carrots, pink guava, papaya, red/pink grapefruit and watermelon so eat more of these, too. Lycopene supplements are also available.
Garlic and prostate health
Garlic is a source of powerful antioxidants such as allicin, which is released when cloves are cut or crushed. Allicin has a number of beneficial effects on the prostate gland and may reduce the progression of BPH.
An Italian study compared 1369 men with BPH to 1451 controls and found those with the highest garlic consumption were 28% less likely to have BPH than those with the lowest intake. When intakes of onions plus garlic were combined, the overall protective effect was a 35% reduced risk of BPH in those who ate them regularly.
Aim to eat garlic and onions at least every other day. Leave chopped or crushed garlic cloves to stand for 10 minutes before adding them to food to maximise allicin formation. It’s also a good idea to add garlic at the end of cooking to retain the most potency. Garlic supplements are available, too.
Lignans and prostate health
Lignans are oestrogen-like hormones, similar to isoflavones, found in a variety of vegetables, including sweet potatoes, chickpeas, squash, pumpkins and their seeds, flaxseed, sesame seeds, kale, broccoli and apricots.
Lignans are activated by bowel bacteria to produce enterolignans which can inhibit an enzyme, 5-alpha reductase, which converts testosterone to the stronger dihydrotestosterone (DHT) in the prostate gland, and which is associated with prostate enlargement.
Flaxseed lignans were evaluated for their ability to alleviate lower urinary tract symptoms in 78 men with BPH. After 4 months, statistically significant improvements were seen in their prostate symptoms score and quality of life compared with those taking placebo. The researchers assessed the therapeutic effects as comparable to those of commonly prescribed drugs (alpha1A-adrenoceptor blockers and 5alpha-reductase inhibitors).
In another study, 1,431 men with BPH took either pumpkin seeds (5 g twice a day), or pumpkin seed extracts or a matching placebo for 12 months. In those eating the pumpkin seeds, the response rate was almost 60% with clinically relevant improvements in symptoms.
Add one to two tablespoons of flaxseeds or pumpkin seeds to your diet per day. They can be lightly toasted for extra crunch and flavour. Sprinkle on cereals, salads, soups, or add to nut and seed mixes for a healthy snack. Ground flaxseed is also available and can be sprinkled over cereals or used during baking.
Vitamin D3 and prostate health
In one study of 155 men in their 70s, blood vitamin D levels were significantly associated with prostate size – the lower their vitamin D level, the larger their prostate gland. Vitamin D3 is found in oily fish, fish liver oils, animal liver, fortified margarine, eggs, butter and fortified milk.
The EU recommended daily amount for vitamin D is 5 mcg (200 IU) per day, while the US daily value is currently 10 mcg (400 IU) which is also hte amount that Public Health england now advise everyone in the UK to take during autumn and winter months when there is insufficient UV light for skin synthesis.
NB Check any multivitamin you take includes vitamin D3 (cholecalciferol) which is more effective at maintaining blood levels than vitamin D2 (ergocalciferol).
Herbal medicines for prostate health
On the herbal front, Saw palmetto and rye pollen extracts are particularly helpful for reducing symptoms of prostate enlargement. Check with your doctor before taking these if you have prostate symptom, however.
Read Quick Nutrition: Prostate Diet, BPH, Prostatitis, Prostate Cancer.
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