A portion of mushrooms was defined as three-quarters of a cup of cooked mushrooms, weighing 150 grams. Two portions are about half a plate. Even one small portion of mushrooms a week was found to have some impact on mild cognitive impairment.
Assistant Professor Lei Feng explained, “This correlation is surprising and encouraging. It seems that a commonly available single ingredient could have a dramatic effect on cognitive decline.”
Data was collected from over 600 Chinese seniors and the study took place over six years.
Mild cognitive impairment is often seen as an early precursor to dementia. Patients with mild cognitive impairment experience forgetfulness, cognitive decline, and memory loss. Changes may be subtle and not impede on daily life as Alzheimer’s disease would.
Professor Fong added, “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 education background. Neuropsychological tests are specifically designed tasks that can measure various aspects of a person’s cognitive abilities. In fact, some of the tests we used in this study are adopted from commonly used IQ test battery, the Wechsler Adult Intelligence Scale (WAIS).”
The participants underwent extensive interviews to determine demographic information, medical history, psychological factors, and dietary habits. Participants also underwent a two-hour psychological assessment and received a dementia rating.
The most commonly consumed mushrooms were golden, oyster, shiitake, and white button mushrooms, as well as dried and canned mushrooms. The researchers suggest that other mushrooms could have benefits as well.
The researchers suggest that a specific compound in mushrooms could be attributed to the benefits of mushrooms on mild cognitive impairment.
Senior research fellow Dr. Irwin Cheah explained, “We’re very interested in a compound called ergothioneine (ET). ET is a unique antioxidant and anti-inflammatory which humans are unable to synthesize on their own. But it can be obtained from dietary sources, one of the main ones being mushrooms.”
Previous studies have shown that low levels of ET were found in patients with mild cognitive impairment. This led researchers to believe that a deficiency in ET could contribute to mild cognitive impairment.
The researchers will move forward to conduct more randomized trials on ET and other plant-based nutrients to uncover their effects on mild cognitive impairment.