We've already heard how the psilocybin from so-called "magic" mushrooms may help to alleviate depression. Well, a new study now suggests that a compound found in all mushrooms could also assist in warding off mild cognitive impairment.
Known as MCI for short, mild cognitive impairment isn't as severe as dementia, although there is strong evidence that the one can lead to the other. People with MCI are generally still able to look after themselves and go about their daily duties unimpeded, but they may have difficulty completing complex tasks or understanding information.
More than six percent of people in their 60s have MCI, and that figure jumps to over 37 percent for people aged 85 or older.
In a six-year study, which was conducted by the National University of Singapore between 2011 and 2017, data was collected from over 600 seniors living in Singapore. Throughout that period, different groups of the participants consumed differing amounts of mushrooms on a daily basis. When a group that consumed more than two standard portions of mushrooms per day was analyzed, the odds of their having MCI were found to be 50 percent lower than those of a control group.
One portion was defined as three quarters of a cup (177 ml) of cooked mushrooms with an average weight of around 150 grams (5.3 oz). The mushroom varieties that were consumed included golden, oyster, shiitake and white button. That said, it is suspected that other types would have produced similar results.
Each participant's cognitive abilities were assessed via an interview, based on a frequently-used IQ test known as the Wechsler Adult Intelligence Scale. "The interview takes into account demographic information, medical history, psychological factors, and dietary habits," says Asst. Prof. Feng Lei, lead author of a paper on the research. "A nurse will measure blood pressure, weight, height, handgrip, and walking speed. They will also do a simple screen test on cognition, depression, anxiety."
It is suspected that the beneficial effect is due to mushrooms' relatively high concentrations of ergothioneine (ET) – this is an antioxidant and anti-inflammatory compound that our bodies are able to produce on their own, but that can also be boosted through dietary sources. In an earlier study, it was found that blood-plasma ET levels were lower in individuals who had MCI. This finding in turn suggested that by increasing their ET intake, people could lower their chances of developing mild cognitive impairment – a theory that the newer study appears to support.
The scientists additionally believe that mushroom compounds including hericenones, erinacines, scabronines and dictyophorines could ward off MCI by promoting the synthesis of nerve growth factors. It's also possible that bioactive compounds from mushrooms may inhibit production of beta amyloid, phosphorylated tau and acetylcholinesterase, all of which have been linked to dementia.
A randomized controlled trial is now planned, in which test subjects will be given pure ergothioneine along with other plant-based compounds.
