Researchers have found that consuming mushrooms three times a week cuts the risk of developing prostate cancer in males.
The study, published in the International Journal of Cancer, found an inverse relationship between mushroom consumption and the development of prostate cancer among middle-aged and elderly Japanese men.
For the findings, a total of 36,499 men, aged 40-79 years who participated in the Miyagi Cohort Study in 1990 and the Ohsaki Cohort Study in 1994, were followed for a median of 13.2 years.
According to the researchers from Tohoku University in Japan, during follow-up, 3.3 per cent of the participants developed prostate cancer.
Mushroom consumption once or twice a week was associated with an eight per cent lower risk of prostate cancer and consumption three or more times per week was associated with a 17 per cent lower risk.
Death rates from prostate cancer — the most commonly diagnosed cancer in men — have stabilized or declined in dozens of countries since the turn of the century, the American Cancer Society reported Tuesday.
In 33 of 44 countries surveyed, the incidence of prostate cancer had stabilized in the last five years for which data was available — and in seven countries, it was down, the report found.
Only four of the countries surveyed, including Bulgaria, saw an increased incidence of prostate cancer, it said.
“In the most recent five years of data examined, prostate cancer incidence and mortality rates are decreasing or stabilizing in most parts of the world,” the study’s author MaryBeth Freeman said.
Prostate cancer deaths were down in 14 countries surveyed and stable in 54 others. Only three countries experienced a rise in prostate cancer deaths, according to the study findings, which were presented Tuesday at a conference in Atlanta.
The United States had the biggest drop in prostate cancers, which Freeman attributed to a decline in the use of a controversial diagnostic test that identified too many non-dangerous tumors.
The incidence of prostate cancers rose in the U.S. during the 1980s and early 1990s when the PSA, or Prostate-Specific Antigen, blood test became widely available.
The test is imprecise, however, and yields too many false positives. It identifies higher than normal levels of PSA, a protein produced by the prostate, which could be a sign of cancer but is more often a symptom of other diseases.
Moreover, some prostate cancers are not aggressive and do not grow enough to pose a risk.