Study Protocol: The Efficacy of Mushroom to Prevent Cognitive Decline in At-Risk Middle-aged 2 Adults and Young-olds Living in the Community 3

Jiatong Shan¹Luwen Cao¹Jiuyu Guo¹Kai Xuan Lim¹Na Li²Yinxia Chao³Yizhen Xie⁴Su Lin Lim¹Irwin Kee Mun Cheah¹Mihir Gandhi¹Tih-Shih Lee³Lei Feng^1*Kaisy Ye^1*

• ¹National University of Singapore, Singapore, Singapore
• ²Changchun University of Chinese Medicine, Changchun, Jilin Province, China
• ³Duke-NUS Medical School, Singapore, Singapore
• ⁴Microbial Safety and Health Research and Development Center, Guangdong Institute of Microbiology, Guangdong Academy of Science, Guangzhou, China

Background: Cognitive function declines with increasing age and maintaining high 30 cognitive functioning especially at late-life remains a challenging question to be addressed. 31 Emerging evidence in the role of mushroom in promoting cognition has been produced from 32 limited observational studies but there is a lack of definitive evidence on both longitudinal 33 relationships from prospective cohort studies and clinical efficacy from clinical trials. Objec-34 tives: To explore the definitive evidence of mushroom on cognitive functions among at-risk 35 middle-aged and young-olds. Design: The first study is a 10-year cognitive assessment fol-36 low-up on an existing cohort, the Diet and Healthy Aging (DaHA), which recruited over 1,000 37 older adults from the year 2010 to the year 2016. The second is a carefully designed random-38 ized controlled trial (RCT) to assess the role of mushrooms in promoting cognitive functioning 39 among around 600 middle-aged adults and young-olds. Participants: Participants were se-40 lected based on specific inclusion criteria, such as being community-living adults aged 45-74 41 years with a family history of dementia, APOE ε4 allele, or subjective cognitive decline, while 42 consuming mushrooms no more than once a week and having no dementia, along with the 43 exclusion of individuals with neurological or psychiatric disorders and significant sensory or 44 motor impairments. Intervention: Participants in the intervention group will consume Pleu-45 rotus citrinopileatus mushroom powder daily for 24 months, with compliance monitored us-46 ing electronic diary apps. The powder contains 7.0 mg/g of ergothioneine (dry weight). Meas-47 urements: Cognitive function including Mini Mental State Examination, Rey Auditory Verbal 48 Learning Test, Symbol Digit Modality test, Clinical Dementia Rating etc along with mental 49 health and biological markers will be measured at baseline, 1 year, and 2 years after baseline.