Benign prostatic hyperplasia (BPH). Source: Wikipedia

Here’s a fairly recent review article on enlarged prostate (benign prostatic hyperplasia or BPH) and how diet affects it.

Benign Prostate Hyperplasia And Nutrition, European Society for Clinical Nutrition and Metabolism, August 2019

BPH is common:

About 75% of men >50 yr of age suffer from BPH related symptoms.

Symptoms:

These include irritative voiding symptoms such as frequency, urgency and nocturia, and obstructive symptoms such as weak urinary stream, incomplete bladder emptying, straining to void, and an intermittent stream.

The article discussed possible causes of BPH, how the condition progresses, and what may contribute to that progression. Some contributing factors: inflammation, elevated estrogens, elevated insulin (and thus insulin resistance). Other elements of the metabolic syndrome are also associated, such as high blood pressure, excessive visceral fat, obesity, and high waist circumference.

Some diet-related things one can do to lessen symptoms:

• Engage in regular exercise (at least 5 days a week) of moderate or vigorous intensity. OK, not diet-related, but a biggie.
• Replace animal protein with vegetable protein. This was a biggie too. “A larger association of BPH has been reported with animal protein than vegetable protein.”
• Limit vegetable oils. “High consumption of unsaturated fatty acids may contribute to lipid peroxidation of the cell membrane and of the components and fluidity of cell membranes, which may affect 5-alpha-reductase activity.”
• Watch calories. “High energy intake may increase abdominal obesity and sympathetic nervous system activity, both of which may increase the risk of BPH. The activation of the sympathetic nervous system and the consequent activation of prostatic smooth muscles may lead to worsening of lower urinary tract symptoms.
• Eat soy. “Soy is an inhibitor of 5-alpha-reductase and a low-potency estrogen. Consumption of non-fermented soy products (tofu, soymilk, edamame) results in a decreased incidence of prostate cancer. Soy may block the receptor sites that the stronger estrogens use to increase the accumulation of DHT.”
• Reduce serum cholesterol. “Metabolites of cholesterol have been identified in the hyperplastic and cancerous prostate gland. Statins lower the risk of both BPH and prostate cancer.”
• Eat less cholesterol and saturated fat (animal foods). “Foods high in cholesterol and saturated fat are rich in arachidonic acid which is the main precursor of inflammation.”
• Reduce preformed long-chain omega-3 fatty acids such as EPA and DHA found in seafood, fish oil, and algal-based supplements. “A high intake of eicosapentanoic acid and docosahexanoic acid was associated with higher prevalence of BPH, lower urinary tract symptoms and BPH related surger. Their high degree of unsaturation promotes lipid peroxidation which in turn leads to an increase in 5a reductase and prostatic dihydrotestosterone, increasing epithelial and stromal growth.”
• Increase plant-based omega-3 fatty acids (vegetables, flax, chia). “[They] help to reduce the influence of prostaglandins and leukotrienes on the inflammatory component of BPH. Whole flaxseeds have the added benefit of lignan fibers, which help to bind estrogen in the gut and thus promote estrogen removal.”
• Eat onions and garlic. “A multitude of benefits have been linked to allium vegetables, namely favorable effects on cardiovascular disease, antiproliferative action on human cancers, and prevention of diseases associated with aging. Garlic and its constituents inhibit key enzymes involved in cholesterol and fatty acid synthesis (including steroid hormones associated with BPH).
• Zinc. The RDA for adult men is 11 mg. Make sure you’re getting it. “A decrease in zinc levels in plasma and prostate tissue in men with BPH (and prostate cancer) has been reported. Zinc supplementation resulted in a reduction of prostate size as well as symptoms of BPH. This may be attributed to blockade of 5-alpha-reductase and/or inhibition of prolactin, resulting in the decreased uptake of testosterone by the prostate and consequent conversion to dihydrotestosterone. It also inhibits the binding of androgens to their receptors in the prostate. Pumpkin seeds are a rich source of zinc, this may explain their potential therapeutic benefit for BPH. Excessive consumption of zinc (>100 mg/day) should be avoided as it may increase the risk of advanced prostate cancer.
• Minimize coffee. “Coffee can decrease zinc absorption by 50%. Caffeine stimulates the adrenergic nervous system (smooth muscles of the prostate) and may worsen BPH symptoms.
• Get some vitamin D. “An increased intake of vitamin D from diet and supplements has shown a correlation with a decrease in BPH prevalence. Vitamin D attaches to its receptors in the prostate and bladder and inhibits prostate growth, lowers excessive contractility, and reduces inflammation. It also has an inhibitory effect on the RhoA/ROCK pathway, along with cyclooxygenase-2 expression and prostaglandin E2 production in BPH stromal cells. Vitamin D analogues of up to 6000 IU/day have shown to decrease the prostate volume in BPH patients.”

I summarized the food-related therapies above. The article also discussed supplements, citing research which backed their effectiveness. I didn’t go into that here but am including part of a table, as a list. To the ones below add Urtica dioica (stinging nettle) which was also shown to be better than placebo.

Since saw palmetto seems to be a popular supplement for BPH, this is what it said:

Saw palmetto has three positive effects on the prostate gland: anti-androgenic, anti-proliferative, and anti-inflammatory [21]. It is aweak inhibitor of 5-alpha-reductase. It also reduces the number of estrogen and androgen (DHT) receptors. Saw palmetto inhibits fibroblast growth factor and epidermal growth factor, and stimulates apoptosis thus further slowing prostate cell proliferation. Its principle ingredient, beta-sitosterol, is also found in soy products (see above), as well as in other herbs used to treat diseases of the prostate including pygeum bark, stinging nettle root, and pumpkin seed extract. Saw palmetto has not shown any benefit in reducing the size of prostate. However, it has been found to improve symptom scores, nocturia, residual urine volume, and urinary flow in patients with BPH.

Conclusion:

Altering the progression of BPH by lifestyle modification, dietary changes or supplementation with nutritional supplements is long known but not widely adapted. Performing moderate exercise 4 to 6 times a week, following a diet rich in vegetable protein and low in animal protein, fortification of diet with zinc and Vitamin D rich foods and intake of supplements like Saw palmetto, Cemilton and Pygeum extracts may help in controlling prostate growth and related LUTS [lower urinary tract symptoms].

There is a lot one can do, short of taking a pharmaceutical drug, to lessen BPH symptoms.