Month: October 2024

The accumulation of the protein amyloid-beta in the brain is one of the primary theories explaining Alzheimer’s. Evidence from University of Cincinnati researchers points to the reduction of amyloid-beta in the brain as the cause of cognitive decline. Researchers believe increasing brain protein levels could improve cognition.

While scientists still don’t know the exact cause of Alzheimer’s, current theories involve the accumulation of a protein called amyloid-beta in the brain.

Researchers at the University of Cincinnati now have evidence that suggests cognitive loss is caused by a decrease in amyloid-beta in the brain, and increasing brain protein levels may improve cognitive function.

According to the study published in the journal Brain, increases in protein levels associated with new Alzheimer’s medicines may explain both the slowing of cognitive impairment and the reduction in amyloid plaques [1].

The loss of Aβ42 contributes to Alzheimer’s.

Alberto Espay, MD, the lead author and professor of neurology at the UC College of Medicine and director and endowed chair of the James J. and Joan A. Gardner Family Center for Parkinson’s Disease and Movement Disorders at the UC Gardner Neuroscience Institute at the University of Cincinnati, and his team discovered that the majority of people with amyloid plaques do not develop Alzheimer’s.

According to Espay, only one-fifth of people with amyloid plaques go on to develop Alzheimer’s by the time they are 85. They found that the ability to create enough Aβ42, a crucial protein for brain health, to maintain those levels within a normal range is what keeps people with amyloid plaques cognitively normal, not the amount of plaques in the brain.

For decades, the accepted consensus in the field has been that a 42-amino-acid protein called amyloid-beta 42 (Aβ42) accumulates into clumps called amyloid plaques, which damage the brain and cause Alzheimer’s.

Espay and teams hypothesized that normal, soluble Aβ42 in the brain is necessary for cell health and that loss of Aβ42, not plaque accumulation, contributes to Alzheimer’s. There is published evidence that indicates dementia develops when Aβ42 levels are very low rather than when plaque levels are high [3].

The brain’s typical reaction to biological, infectious, or metabolic stress seems to be the conversion of Aβ42 into plaques, according to Espay’s findings.

Focusing on monoclonal antibody therapies.

For this study, researchers examined data from over 26,000 participants in 24 randomized clinical trials for newly approved Alzheimer’s treatments using monoclonal antibodies [3]. They assess cognitive impairment and differences Aβ42 levels before and after treatment.

After observing that these novel medicines inadvertently raised Aβ42 levels in the brain, Espay and his colleagues decided to concentrate on them.

According to Espay, Aβ42 is a protein that responds to various infectious and toxic exposures to protect the brain. During that process, Aβ42 stops working and changes into amyloid plaques. One could think of the plaques as Aβ42’s tombstones.

He added that they were interested in discovering whether any cognitive advantages may be explained by the rise in Aβ42 as much as by the decline in amyloid plaques. The data was available for extraction from each monoclonal antibody trial report’s supplemental material.

Higher levels of amyloid-beta are associated with slower cognitive deterioration.

Researchers analyzed the study data and found that slower cognitive impairment and clinical decline were independently linked to greater levels of Aβ42 following monoclonal antibody treatment.

The same group’s previous research has already demonstrated that, regardless of the levels of amyloid plaques, normal cognition is linked to cerebrospinal fluid Aβ42 levels above a particular threshold of compensation [2]. Higher baseline Aβ42 levels predict a slower progression to dementia, even in people with genetic types of Alzheimer’s.

Espay said that Alzheimer’s is a result of Aβ42 loss rather than amyloid buildup. Regardless of how many plaques there are, the brain does not swell but continues undergoing atrophy. Future treatments should directly increase Aβ42 rather than indirectly, as the current antibodies do.

Researchers are investigating treatments that could boost Aβ42 levels as a type of rescue treatment.

Alzheimer’s Research Association is a non-profit organization dedicated to helping caregivers of Alzheimer’s disease and dementia. We provide the latest information and news about the illness and helpful tips to help caregivers cope with their daily caregiving challenges. We realize the most important thing that a caregiver needs is financial assistance. Therefore, we provide grants to caregivers to ease their financial burden. Caregivers can apply for grants here: Alzheimer’s Grant Application. 

You can also help caregivers in their endeavor by donating as much as possible: Donation To Alzheimer’s Research Associations.

References

1. Abanto, J., Dwivedi, A.K., Imbimbo, B.P. and Espay, A.J., 2024. Increases in amyloid-β42 slow cognitive and clinical decline in Alzheimer’s disease trials. Brain, 147(10), pp.3513-3521.
2. Sturchio, A., Dwivedi, A.K., Malm, T., Wood, M.J., Cilia, R., Sharma, J.S., Hill, E.J., Schneider, L.S., Graff-Radford, N.R., Mori, H. and Nübling, G., 2022. High soluble amyloid-β42 predicts normal cognition in amyloid-positive individuals with Alzheimer’s disease-causing mutations. Journal of Alzheimer’s Disease, 90(1), pp.333-348.
3. Cummings, J., Osse, A.M.L., Cammann, D., Powell, J. and Chen, J., 2024. Anti-amyloid monoclonal antibodies for the treatment of Alzheimer’s disease. BioDrugs, 38(1), pp.5-22.
4. New study challenges amyloid-beta theory on cause for Alzheimer’s disease. Medical News Today. https://www.medicalnewstoday.com/articles/brain-protein-challenges-amyloid-beta-theory-cause-alzheimers-disease. Published Online: 18th September, 2024. Accessed: 14th October, 2024.
5. Boosting brain protein levels may slow decline from Alzheimer’s. Science Daily. https://www.sciencedaily.com/releases/2024/09/240911112040.htm. Published Online: 11th September, 2024. Accessed: 15th October, 2024.
6. Alzheimer’s decline may be slowed by protein boost. UC News. https://www.uc.edu/news/articles/2024/09/alzheimers-decline-may-be-slowed-by-protein-boost.html. Published Online: 12th September, 2024. Accessed: 15th October, 2024.

Overexposure to light pollution at night may increase the risk of acquiring Alzheimer’s. In a recent study, researchers discovered that light pollution had a stronger link with Alzheimer’s prevalence in adults aged 65 and younger than any other risk factor investigated.

Light pollution affects around 80% of the world’s population and is associated with several health issues, including sleep disorders, anxiety, and fatigue [1, 2] .

According to a recent study, there may be a substantial increase in Alzheimer’s risk due to light pollution [3] .

Numerous risk factors are known to increase the likelihood of getting Alzheimer’s. These include lifestyle choices like smoking and drinking alcohol , as well as medical disorders like diabetes , high blood pressure , and heart disease. This latest study provides compelling evidence that light pollution is an additional risk factor for the condition.

Frontiers in Neuroscience published the study.

Brighter Nights May Increase Alzheimer’s Risk: The Study

The study’s authors investigated satellite data to ascertain the average nighttime light intensity in the United States from 2012 to 2018.  

They ranked the lower 48 states based on the average nighttime light intensity. They then divided the states into five groups, ranging from the ones with the lowest average nighttime light intensity to those with the highest average nighttime light intensity. 

The researchers also collected Medicare data to evaluate Alzheimer’s prevalence in each state.

They discovered statistical disparities between states that were the darkest and the brightest at night. There was a positive correlation between the prevalence of Alzheimer’s disease and higher levels of light pollution at night.

The research team observed the effect in people under and over 65, men and women , and all races except Asian Pacific Islanders.

They discovered that, compared to other possible disease risk factors such as chronic kidney disease, alcohol abuse, depression, and obesity, nocturnal light pollution showed a stronger link with the occurrence of Alzheimer’s in adults 65 years of age and older.

However, for this group, some risk factors were more strongly associated with Alzheimer’s disease than light pollution, which included diabetes , stroke, and hypertension .

In people under the age of 65, the study authors discovered that higher levels of nighttime light pollution were related to a higher prevalence of Alzheimer’s than any other risk factor investigated.

Limitations of the Study

As with other studies, it is critical to acknowledge that this research has limitations. Some factors were not controlled for in this investigation, which may have affected the outcomes.

For example, the study did not measure artificial indoor light, such as that emitted by phones, televisions, and other electronic devices. Such factors are also linked to sleep problems and may influence the outcomes.

Another factor the team did not adjust and may have influenced the results is the impact of air pollution . Light pollution has a connection to air pollution since brightly lit places are often present in busier urban centers. These metropolitan settings have more vehicle traffic, industrial activity, and trash disposal. All of this contributes to higher concentrations of dangerous particulate matter, which is linked to dementia and cognitive decline.

Furthermore, the study’s data was limited to the US population. The analysis did not include health and socioeconomic status disparities, which are significant risk factors for Alzheimer’s and may have played a role.

Also, the study only looked at Alzheimer’s prevalence rather than incidence, and the Medicare data was limited.

However, this is not the first study to find a link between nighttime light pollution and cognitive health.

Previous studies have also found a link between dementia and nighttime light pollution. According to studies conducted in China and Italy, people who live in areas with high levels of light pollution are more likely to acquire moderate cognitive impairment and late-onset dementia [4, 5] . The most recent study broadens the body of data by demonstrating a direct correlation between light pollution and Alzheimer’s disease [3].

Studies have also indicated a connection between light pollution and Parkinson’s disease [6] .

Sleep: A Significant Risk Factor

The specific reason why nighttime light pollution is associated with an increased Alzheimer’s risk remains unknown. However, it might have something to do with how light pollution ruins sleep.

Sleep plays a significant part in dementia development. According to research, getting too little sleep can harm the brain’s glymphatic system, which is a network of vessels that helps remove waste and flush out the harmful proteins that are assumed to accumulate and lead to Alzheimer’s [7] . There is a theory that these proteins don’t get washed away and continue to build up when we don’t get enough sleep.

Nighttime light exposure can potentially interfere with a person’s circadian rhythm. This internal brain clock regulates our sleep and wake cycles by adjusting to variations in the light surrounding us. Disturbing this cycle might lead to inflammation and make a person more prone to illness. Such inflammation can lead to a rise in amyloid, a harmful protein usually present in the brains of Alzheimer’s patients . 

Other Risk Factors for Alzheimer’s

The precise cause of Alzheimer’s in the majority of cases remains unclear. However, scientists think it’s probably an intricate combination of lifestyle, health, and hereditary factors in addition to age-related brain changes.

Some risk factors, such as age and family history, are unchangeable. Nonetheless, there may be ways to change a few risk factors linked to Alzheimer’s.

These include unhealthy eating habits, poor sleep , smoking, alcohol abuse, physical inactivity, social isolation, and a lack of mental stimulation.

Awareness Can Help

The researchers observe that in some parts of the world, particularly urban areas, lights never go off.

They said up to 80% of the world’s population suffers from light pollution, which prevents most individuals living in urban and suburban regions from seeing the natural celestial light. Even though most people believe that artificial light at night is safe or even helpful, light pollution has adverse effects on the environment, human behavior, biology, and health.

The researchers intend to increase public awareness of the potential hazards related to nighttime light exposure with their findings.

Robin Voigt-Zuwala, Ph.D., first author of the study and an associate professor at Rush University Medical Center, stated in a press release that Understanding the link should enable people to easily modify their lifestyle, especially those who have risk factors for Alzheimer’s. Using eye masks when sleeping or utilizing blackout curtains are simple adjustments. Those who live in places with high levels of light pollution will find this very helpful [8] .

Alzheimer’s Research Association is a non-profit organization dedicated to helping caregivers of Alzheimer’s disease and dementia. We provide the latest information and news about the illness and helpful tips to help caregivers cope with their daily caregiving challenges. We realize the most important thing that a caregiver needs is financial assistance. Therefore, we provide grants to caregivers to ease their financial burden. Caregivers can apply for grants here: Alzheimer’s Grant Application . 

You can also help caregivers in their endeavor by donating as much as possible: Donation To Alzheimer’s Research Associations .

References

1. Falchi, F., Cinzano, P., Duriscoe, D., Kyba, C.C., Elvidge, C.D., Baugh, K., Portnov, B.A., Rybnikova, N.A. and Furgoni, R., 2016. The new world atlas of artificial night sky brightness. Science advances, 2(6), p.e1600377.
2. Chepesiuk, R., 2009. Missing the dark: health effects of light pollution. Environ Health Perspect., 117(1), A20–A27.
3. Voigt, R.M., Ouyang, B. and Keshavarzian, A., 2024. Outdoor Nighttime Light Exposure (Light Pollution) is Associated with Alzheimer’s Disease. medRxiv.
4. Chen, Y., Tan, J., Liu, Y., Dong, G.H., Yang, B.Y., Li, N., Wang, L., Chen, G., Li, S. and Guo, Y., 2022. Long-term exposure to outdoor light at night and mild cognitive impairment: a nationwide study in Chinese veterans. Science of the total environment, 847, p.157441.
5. Mazzoleni, E., Vinceti, M., Costanzini, S., Garuti, C., Adani, G., Vinceti, G., Zamboni, G., Tondelli, M., Galli, C., Salemme, S. and Teggi, S., 2023. Outdoor artificial light at night and risk of early-onset dementia: A case-control study in the Modena population, Northern Italy. Heliyon, 9(7).
6. Romeo, S., Viaggi, C., Di Camillo, D., Willis, A.W., Lozzi, L., Rocchi, C., Capannolo, M., Aloisi, G., Vaglini, F., Maccarone, R. and Caleo, M., 2013. Bright light exposure reduces TH-positive dopamine neurons: implications of light pollution in Parkinson’s disease epidemiology. Scientific Reports, 3(1), p.1395.
7. Buccellato, F.R., D’Anca, M., Serpente, M., Arighi, A. and Galimberti, D., 2022. The role of glymphatic system in Alzheimer’s and Parkinson’s disease pathogenesis. Biomedicines, 10(9), p.2261.
8. Excessive light pollution may increase risk of Alzheimer’s, especially in younger people. EurekAlert. News Release. https://www.eurekalert.org/news-releases/1054593. Published Online: 6th September, 2024. Accessed: 1st October, 2024.
9. Why light pollution may be linked to greater risk of Alzheimer’s disease. The Conversation. https://theconversation.com/why-light-pollution-may-be-linked-to-greater-risk-of-alzheimers-disease-238942. Published Online: 18th September, 2024. Accessed: 1st October, 2024.
10. Alzheimer’s risk in younger people linked to nightly light pollution in new study. Medical News Today. https://www.medicalnewstoday.com/articles/higher-alzheimers-risk-younger-people-linked-nightly-light-pollution-study. Published Online: 6th September, 2024. Accessed: 1st October, 2024.