Mushroom consumption may curb cognitive decline in seniors, study finds

15 Mar 2019 --- A weekly serving of more than three-quarters of a cup of cooked mushrooms – the equivalent of 300 grams – may help facilitate the alleviation of mild cognitive impairment (MCI) in seniors by up to 50 percent. This is according to a six-year study conducted from 2011 to 2017 by researchers at the Department of Psychological Medicine and Department of Biochemistry at the Yong Loo Lin School of Medicine at the National University of Singapore (NUS). The research spotlights the antioxidant L-ergothioneine (ET), which holds anti-inflammatory properties and is present in fungi.

Assistant Professor Feng Lei of the NUS Department of Psychological Medicine and the lead author of the research program calls the correlation both “surprising and encouraging.”

“It seems that a commonly available single ingredient could have a dramatic effect on cognitive decline,” he states.

Over 600 Singaporeans aged 60 and above were interviewed against the criterion of mushroom consumption habits and cognitive capacity in the analysis, which published its results in the online Journal of Alzheimer’s Disease. The research focused on the six most commonly consumed mushrooms in Singapore, namely: Golden, oyster, shiitake and white button mushrooms, in dried and canned forms.

The research did not examine how the mushrooms were prepared by participants of the study.

Isolated compound in mushrooms might help slow mental decline

Spotlighted by the study is the compound ET, which is identified as an antioxidant with anti-inflammatory properties – produced only by microorganisms and fungi (primarily mushrooms) in nature and absorbed by humans through their diet.

Preliminary studies by the research team at NUS concluded that levels of ET present in blood plasma of participants with MCI were observably lower than the age-matched subjects who were identified as healthy under given parameters. 

This given risk factor for neurodegeneration has led to the belief that increasing ET intake through mushroom consumption might help sustain cognitive health and performance.

The study also identifies other compounds contained within mushrooms that may prove advantageous for decreasing the risk of cognitive decline. The synthesis of nerve growth may be promoted by certain hericenones, erinacines, scabronines, and dictyophorines found in the fungi. Bioactive compounds within mushrooms were cited as additional inhibitors of neurodegeneration, as they were found to have reduced the production of harmful beta-amyloid, phosphorylated tau and Acetylcholinesterase.

Identifying mild cognitive impairment in seniors
MCI is identified as a stage in-between the initial cognitive decline related to aging and the onset of dementia. Studies by Alzheimer’s Research UK estimate that each year, 10-15 percent of people with a diagnosis of MCI are likely to develop dementia.

Elderly individuals diagnosed with MCI most often display signs of impairment to memory as well as deficits in other cognitive functions such as language, attention and visuospatial perceptions. Still, it is noted that these symptoms do not always appear severe and may not manifest as extreme disabilities that hamper normal life activities, as would be a trait of Alzheimer’s and other variations of dementia.

Assistant Professor Feng clarified, “People with MCI are still able to carry out their normal daily activities. So, what we had to determine in this study is whether these seniors had poorer performance on standard neuropsychologist tests than other people of the same age and educational background.” 

For this study, researchers adopted tests based on the commonly used IQ test battery, the Wechsler Adult Intelligence Scale (WAIS) along with an assessment for dementia. Overall results were discussed in detail with psychiatrists to attain a diagnostic consensus.

Future steps in brain health and nutrition
The ongoing NUS research program – carried out with backing from the Life Sciences Institute and the Mind Science Centre at NUS and the Singapore Ministry of Health’s National Medical Research Council – is planning future randomized controlled trials studying the isolated ET compound, in addition to other plant-based ingredients linked to sustained brain health. These include L-theanine and catechins from tea leaves which are both potential deterrents to the onset of cognitive decline.

Global attention on the benefits of consistent ET consumption has already gained traction. Earlier this month, Tetrahedron, which specializes in developing ingredients for the nutraceutical, pharmaceutical and personal care industries, received Novel Food status from the European Commission (EC) for its Ergoneine brand, which is a pure, synthetic source of L-ergothioneine touted as protecting against oxidative stress and supporting healthy aging.

By Benjamin Ferrer