Men who eat mushrooms reduce their risk of developing prostate cancer, according to a new study.
Researchers who followed more 36,000 Japanese men for up to a quarter of a century found a link between eating mushrooms and a lower risk of prostate cancer.
Eating mushrroms was particularly beneficial for men over 50 who also eat lots of meat and dairy products but little fruit and veg, according to the findings of the first long-term study of its kind published in the International Journal of Cancer.
Prostate cancer is one of the most common forms of cancer affecting men, with more than 1.2 million new cases diagnosed worldwide in 2018, the risk increasing with age.
In the UK, about one in eight men will be diagnosed with prostate cancer in their lifetime.
The researchers explained that prostate cancer begins when cells in the prostate gland – a small walnut-shaped gland found only in men, which produces the fluid that forms part of the semen – start to grow out of control.
Mushrooms are widely in used in Asia, both for their nutritional value and medicinal properties.
Study lead author Assistant Professor Shu Zhang, of Tohoku University School of Public Health in Japan, said: “Test-tube studies and studies conducted on living organisms have shown that mushrooms have the potential to prevent prostate cancer.
“However, the relationship between mushroom consumption and incident prostate cancer in humans has never been investigated before.
“To the best of our knowledge, this is the first cohort study indicating the prostate cancer-preventive potential of mushrooms at a population level.
“Although our study suggests regular consumption of mushrooms may reduce the risk of prostate cancer, we also want to emphasise that eating a healthy and balanced diet is much more important than filling your shopping basket with mushrooms.”
The researchers monitored two groups consisting of a total of 36,499 men between the ages of 40 and 79 in Miyagi and Ohsaki, Japan, from 1990 and 1994 respectively.
The follow-up duration for the Miyagi cohort extended from June 1, 1990, to December 31, 2014, while the follow-up duration for the Ohsaki cohort extended from January 1, 1995, to March 31, 2008.
The men were asked to complete a questionnaire related to their lifestyle choices, such as mushroom and other food consumption, exercise, smoking and drinking habits, as well as providing details of their education, family and medical history.
Long-term follow-up of the participants indicated that eating mushrooms on a regular basis reduces the risk of prostate cancer in men, and was especially significant in men aged 50 and older and in men whose diet consisted largely of meat and dairy products, with limited consumption of fruit and veg.
Statistical analysis of the data suggested that regular mushroom consumption was related to a lower risk of prostate cancer regardless of how much fruit and veg, or meat and dairy products were consumed.
Of the participants, 3.3 per cent developed prostate cancer during the follow-up period.
Participants who ate mushrooms once or twice a week had an eight per cent lower risk of developing prostate cancer, compared to those who ate mushrooms less than once per week, while those who ate mushrooms three or more times per week had a 17 per cent lower risk than those who ate mushrooms less than once a week.
Prof Zhang said: “Mushrooms are a good source of vitamins, minerals and antioxidants, especially L-ergothioneine.”
Naturally occurring amino acid L-ergothioneine is believed to mitigate against oxidative stress, a cellular imbalance resulting from poor diet and lifestyle and exposure to environmental toxins that can lead to chronic inflammation that is responsible for chronic diseases such as cancer.
Prof Zhang added: “The results of our study suggest mushrooms may have a positive health effect on humans.
“Based on these findings, further studies that provide more information on dietary intake of mushrooms in other populations and settings are required to confirm this relationship.
“Considering the average American consumes less than five grams of mushrooms per day, which is lower than the 7.6g consumed by the participants in this study one would expect that even a small increase in mushroom consumption to offer potential health benefits.”