Healthnotes Newswire (January 10, 2008)—Prostate enlargement is common in men as they age, but not inevitable: A new study has found that men who frequently eat onions and garlic are less likely to have benign prostatic hyperplasia (BPH).

An increasingly frequent need to urinate is a hallmark of BPH, which is a noncancerous enlargement of the prostate gland. When enlarged, the gland presses on the urinary “plumbing,” which slows the urinary stream and interferes with the bladder emptying. Sleep disruption is common in men with BPH, but more serious problems can also occur, including severe, painful urinary urging and recurrent urinary tract infections.

Some evidence suggests that eating a diet rich in vegetables, fruits, and soy foods might help men avoid BPH, and that eating too many dairy foods might increase the risk. Garlic and onions, members of the vegetable family known as allium, have demonstrated a number of health effects such as fighting infection and preventing heart disease and some cancers. Their effect on BPH is not clear but previous research has suggested that garlic might be beneficial.

The new study, published in Urology, compared the diets of 1,369 men with and 1,451 men without BPH. Men who ate onions four or more times per week had a 59% lower BPH risk than men who never ate onions. Garlic was also found to be protective: men who ate the most garlic had a 28% lower risk than men who never did.

Some medications for BPH and the herbal supplement saw palmetto (Serenoa repens) work by reducing the levels of hormones believed to play a role in BPH development. Although it is not known for sure, garlic might also reduce the levels of these hormones by inhibiting cholesterol production, which is needed for hormone synthesis. In addition, onions and garlic contain antioxidants, enzymes, and other plant chemicals that might benefit the prostate gland.

“This first study on the potential role of allium vegetables on BPH suggests that a diet rich in onion and garlic may have a favorable effect on the odds of developing BPH,” the researchers concluded.

Commented Julianne Forbes, a naturopathic doctor in Maine, “The symptoms of BPH affect many people and can dramatically diminish their quality of life. Onions and garlic, which might help, are safe and inexpensive, and should be easy to incorporate into the diet.”

(Urology 2007;70:672–6)