SINGAPORE: Seniors who eat more than two standard portions of mushrooms weekly may be half as likely to develop mild cognitive impairment (MCI), according to the findings of a study revealed on Tuesday (Mar 12).
The study, which was conducted on 600 Chinese seniors over the age of 60, defined a portion as three quarters of a cup of cooked mushrooms with an average weight of around 150g.
Two portions would be equivalent to about half a plate.
"While the portion sizes act as a guideline, it was shown that even one small portion of mushrooms a week may still be beneficial to reduce chances of MCI," according to a press release from the National University of Singapore (NUS).
“This correlation is surprising and encouraging. It seems that a commonly available single ingredient could have a dramatic effect on cognitive decline,” said assistant professor Feng Lei of the NUS Department of Psychological Medicine.
The ingredient has been identified as ergothioneine, "a unique antioxidant and anti-inflammatory which humans are unable to synthesise on their own," said Dr Irwin Cheah, a senior research fellow at the NUS Department of Biochemistry.
The study, conducted between 2011 and 2017, involved six commonly consumed types of mushrooms in Singapore: golden, oyster, shiitake, white button, dried and canned mushrooms.
To ensure scientific integrity, extensive interviews and tests were carried out with the participants. The seniors' demographic information, medical history, psychological state, dietary habits and physical abilities were taken into account.
"People with MCI are still able to carry out their normal daily activities. So, what we had to determine in this study was whether these seniors had poorer performance on standard neuropsychologist tests than other people of the same age and education background," Asst Prof Feng, the lead author of the study, said.
A simple screen test on cognition, depression and anxiety was also conducted, followed by a standard neuropsychological assessment. The results of these tests were discussed in depth with expert psychiatrists.
Commonly acknowledged as the stage between the cognitive decline that comes with ageing naturally and the more serious dementia, MCI symptoms include memory loss or forgetfulness and decline in cognitive functions including language, attention span and perceiving objects.