Green tea might help alleviate Urinary Incontinence (UI) in middle-aged and older women.
Professor Andy Lee, from the Curtin Health Innovation Research Institute, collaborated with a Japanese research team to examine the effects of green tea consumption in a cohort of Japanese women aged between 40 and 75.
While UI was a problem for 28 per cent of participants, the results showed that those who drank four or more cups of green tea daily were significantly less likely to suffer from the condition.
"The difference between green tea and black tea is that the former is a non-fermented product," Professor Lee said.
"Both teas are produced from the leaves of Camelia sinensis, but green tea has undergone far less oxidation during processing, and it has far less caffeine," he said.
Of the principal chemical constituents of green tea, epigallocatechin gallate, or EGCG, is the most active polyphenol. Previous research has shown EGCG to be mainly responsible for the inhibitory effect of green tea on urinary stone formation.
EGCG has been demonstrated to cause a dose-dependent decrease in urinary bladder cancers. Another experimental study showed that green tea could reduce glucose levels and renal injury associated with abnormal glucose-related oxidative stress in diabetic nephropathy.
UI is a distressing condition and a costly problem for middle-aged and older people. Up to 35 per cent of the population aged 60 and over are estimated to suffer from UI, with women twice as likely to suffer from the condition as men. With around 50 per cent of nursing home admissions relating to UI, it is a serious problem worldwide.
A cross-sectional study in Finland reported that consumption of certain foods and beverages can affect the prevalence of UI and lower urinary tract symptoms. Age, gender, obesity and smoking are also established risk factors.
"We would now like to undertake a population-based prospective cohort study to confirm the benefits," Professor Lee said.
"But, as part of a preventative strategy, we recommend that women replace their consumption of other beverages, such as coffee, with green tea."
The study was recently published in the leading journal Neurourology and Urodynamics