TL;DR
Turn your wind-down time into listening time
- Thousands of audiobooks, podcasts and originals
- Listen on your phone, tablet or Echo — also offline
- Cancel anytime
Researchers found that older adults with faster cognitive decline had fewer large nerve fibers, abnormal myelin buildup and lower levels of the protective protein NRF2 in oligodendrocytes. Experiments in mice suggest reduced NRF2 in these cells can cause similar brain changes, but whether medicines targeting the pathway can slow cognitive decline in people is not yet known.
Researchers studying human brain tissue and mice have linked reduced activity of a cell-protective protein, NRF2, in myelin-producing brain cells to changes associated with faster cognitive decline in older age. The findings, published in Nature Medicine, suggest that oligodendrocytes—cells that normally insulate nerve fibers—may become dysfunctional as the brain ages, though the research does not show that an existing drug can prevent cognitive decline in people.
The study was led by researchers from the University of Edinburgh and the UK Dementia Research Institute. The team examined participants in the Lothian Birth Cohort 1936, whose cognitive abilities had been tracked from childhood into old age. From 1,091 people enrolled in the cohort, 866 completed additional cognitive testing after age 70. Tests between ages 70 and 82 measured memory, information-processing speed and spatial reasoning.
Nearly all participants experienced some decline, but the rate differed. In post-mortem brain tissue from a subset of participants, greater decline was associated with fewer large nerve fibers and abnormal buildup of myelin, the coating that helps electrical signals travel along nerve fibers. These tissue features were associated with the rate of decline, not simply with a person’s cognitive test performance at a single age.
The researchers found lower levels of NRF2 in oligodendrocytes among people with more severe decline. In mice, reducing NRF2 specifically in these cells led to excessive myelin, loss of large nerve fibers and less improvement in cognitive performance as the animals aged. The experiments support a possible direct role for NRF2 loss in the observed changes, but animal results do not establish that the same mechanism causes human cognitive decline.
A New Target in Aging Brain Research
The findings broaden the picture of how age-related cognitive decline may develop. Oligodendrocytes are usually described as support cells because they build and maintain myelin. The study suggests that when their protective systems falter, these cells may contribute to damage affecting the nerve fibers they normally support. That makes cell health and myelin maintenance potential areas for further research, alongside the nerve cells themselves.
The work also points to a possible treatment avenue: medicines that affect the NRF2 pathway are already used for other neurological conditions, including multiple sclerosis. The researchers say this creates a reason to investigate whether the pathway could be relevant to age-related decline. It is not evidence that those medicines work for older adults with cognitive decline, and any treatment use would require testing for benefit and safety in that population.
As an affiliate, we earn on qualifying purchases.
From Lifelong Testing to Brain Tissue
The Lothian Birth Cohort gives researchers an unusually long record of cognitive performance, allowing them to compare changes across later life rather than relying only on a single assessment. In this study, the researchers connected those test histories with brain tissue collected after participants died. That design allowed the team to identify associations between the pace of cognitive change and tissue features, including myelin abnormalities and the number of large nerve fibers.
Human tissue findings alone cannot show what caused the changes. The mouse experiments addressed part of that question by lowering NRF2 in oligodendrocytes and observing similar abnormalities. The study therefore combines human associations with experimental evidence in animals, but it does not establish a complete causal pathway in people.
The researchers also point to prior studies in which increasing NRF2 activity was associated with improved cognitive function in people with multiple sclerosis. That evidence concerns a different condition and does not confirm that NRF2-targeting drugs will preserve cognition during normal aging.
“As the prevalence of cognitive decline is rising with an aging population and no current treatments exist, we are excited about this work as it points to a potential strategy for new therapeutic strategies to preserve cognitive ability in aging.”
— Veronique Miron, MRC Senior Non-Clinical Fellow and UK Dementia Research Institute group leader at the University of Edinburgh and St. Michael’s Hospital
As an affiliate, we earn on qualifying purchases.
Human Treatment Evidence Is Missing
The research does not show that low NRF2 activity is the sole cause of cognitive decline or that raising it would prevent or reverse decline in people. The human findings are associations drawn from a subset of a cohort, while the intervention experiments were conducted in mice. The report does not establish which biological changes occur first in humans, or how much they contribute compared with other processes involved in aging.
It also remains unclear whether medicines that act on the NRF2 pathway would reach the relevant brain cells at an effective dose, produce meaningful cognitive benefits, or carry acceptable risks for older adults. The study identifies a potential therapeutic target, not a proven treatment or a basis for individual medical decisions.
cognitive decline support supplement
As an affiliate, we earn on qualifying purchases.
As an affiliate, we earn on qualifying purchases.
Testing the Pathway in People
Further research will need to test whether changing NRF2 activity can protect oligodendrocytes, myelin and nerve fibers in ways that preserve cognition in older people. That could include studies of how the pathway behaves over time, followed by clinical trials if preclinical work supports a suitable treatment approach. Researchers would need to measure both cognitive outcomes and safety rather than assume results from multiple sclerosis or mouse studies apply to age-related decline.
For now, the reported development is a new research lead: evidence in human tissue paired with experiments suggesting that loss of NRF2 in oligodendrocytes can produce similar brain changes in mice. Whether that mechanism can be safely targeted to slow cognitive decline remains to be established.
As an affiliate, we earn on qualifying purchases.
Key Questions
What did the researchers find?
People who had experienced greater cognitive decline tended to have fewer large nerve fibers, abnormal myelin buildup and lower NRF2 levels in oligodendrocytes in examined brain tissue. The study also found similar changes after NRF2 was reduced in oligodendrocytes in mice.
What do oligodendrocytes do?
Oligodendrocytes produce and maintain myelin, the insulating coating around nerve fibers that helps electrical signals travel through the brain.
Does the study prove NRF2 loss causes cognitive decline in people?
No. The human results show associations. Experiments in mice support a possible causal role for reduced NRF2 in oligodendrocytes, but they do not prove the same process causes decline in humans.
The study does not show that. Some medicines affect the NRF2 pathway and are used for other conditions, but their safety and effectiveness for age-related cognitive decline would need to be tested in appropriate studies.
Source: rss
Halloween Picks
halloween
As an affiliate, we earn on qualifying purchases.
