Publications by MELODEM Participants

The 2024 PNAS publication “Effect of a Cash Transfer Intervention on Memory Decline and Dementia Probability in Older Adults in Rural South Africa” evaluated the impact of a randomized cash transfer on long-term cognitive outcomes in a low-income, aging population.

The study was possible because a randomized study of cash transfers ($36 US per month at time of study, equivalent to about 67% of the average household monthly consumption) happened to include the households of 862 participants in the HAALSI study (Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community, 2014–2022). Because HAALSI was already tracking cognitive changes longitudinally, they could compare whether changes were slower for older adults in households randomized to receive a cash transfer. The cash transfer study was launched 2011-2012, and cash payouts continued for 1-5 years based on the age of the teenage girl in the household (who were the original intended beneficiaries of the intervention). HAALSI baseline was in 2014/15 and follow-up continued for 7 years.

Older adults (average age 61 years, SD=12 years) in households who received a short-term cash transfer experienced slower memory decline after 7 years of follow-up in the HAALSI cohort study, with stabilized or slower declines in memory scores compared to those who did not receive the transfer. At the end of follow-up, older adults in households that received the cash transfer had a 3-percentage point lower probability of dementia compared to households that did not receive the transfer. This study showed that modest cash transfers to older adults in low-income settings can slow memory decline and reduce dementia risk, emphasizing financial support as a tool for improving brain health in resource-limited areas.

This manuscript was led by Dr. Molly Rosenberg at the Indiana University School of Public Health and senior authored by long-term MELODEM participant Dr. Lindsay Kobayashi of University of Michigan.  Congratulations to the authors on such an impressive and creative study.

The 2024 Neurology publication “Associations Between Blood-Based Biomarkers and Cognitive and Functional Trajectories Among Participants of the MEMENTO Cohort,” explores the relationship between blood-based Alzheimer’s Disease biomarkers and cognitive and functional trajectories over five years in older adults from the French MEMENTO cohort. With senior author Dr. Carole Dufouil and first-author Dr. Leslie Grasset, the team assessed the links between baseline biomarkers from blood samples and cognitive tests, including the Mini-Mental State Examination (MMSE), Free and Cued Selective Reminding Test (FCSRT), Semantic Fluency Test, and Trail Making Tests A and B (TMT-A and TMT-B).

Elevated blood biomarkers p-tau181 (linked to Alzheimer’s) and neurofilament light chain (NfL, indicating nerve cell damage), were associated with faster decline in both multiple cognitive measures (e.g., assessing memory and language), as well as measures of physical functioning and autonomy (e.g., a battery of physical performance tasks such as gait speed, balance, and strength and a brief assessment of limitations in instrumental activities of daily living) physical tasks. Together, p-tau181 and NfL were associated with greater cognitive and functional decline than either alone. A lower Aβ42/40 ratio was only associated with a slightly faster cognitive decline in FCSRT and semantic fluency, as well as a slightly faster progression of disability. The clinical significance of this study lies in its potential to better understand the biomarkers that link with the biological progression of Alzheimer’s and pathologies that cause dementia.