By Dianne Anderson

Whatever keeps the community up at night – or makes them pull the covers over their head to not face the day – probably won’t surface for years to come, but Dr. Karen Lincoln sees where it starts in the early stages through brain imaging.

In and of itself, she said it’s not so much about sleep, but rather why advanced aging disproportionately impacts the Black community. Two of her landmark studies, Sleep Tight and Express Yourself, show how and why everyday discrimination and microaggressions are taking a dramatic toll on health.

Earlier this year, Dr. Lincoln joined UCI faculty as a professor, and is also the director of the Center for Environmental Health Disparities Research.

She said too much sleep or lack of it is showing up in unexpected ways in the Black community, who, when compared to whites, show signs of aging faster and higher risk for Alzheimer’s disease.

“You can take a 60-year-old Black person and 60-year-old white person, even though they are the same chronological age, the Black person would be 67 years just because of exposure to all these social stressors,” said Dr. Lincoln, Ph.D., MSW, MA.

A good night’s sleep is between seven to eight hours each night, which helps the brain clear metabolic waste to prevent premature aging or Alzheimer’s.  But not enough or too much sleep is equally bad when it comes to clearing the brain of toxins.

Her research focused on Black Americans and Caribbean Americans. The data is new, but the next step is aggregating specific demographics within the Black community to see which groups are impacted, such as age, male or female.

From what she sees, about 25% of participants are getting over nine hours of sleep a night. As a mental health disparities researcher, she said that number is significant.

“Part of it is looking at depression, which is fairly prevalent among Black Americans and often undiagnosed. It certainly skyrocketed during COVID, it’s not something we are getting diagnosed with or treated for. That’s one explanation that I could explore, that [depressed] people sleep more,” she said.

Age also plays a factor in sleeping more, along with those with two or more medical conditions. The time of day that people sleep, which may not be at night, could be an issue.

But Black Americans tend toward the worst quality of sleep in America, and also have the highest risk of Alzheimer’s and dementia. It is the basis of her research, which is charting new territory.

“We now understand why sleeping too much is associated with cognitive impairment among Black Americans because it alters the brain clearance system,” she said

Knowing that too much or too little sleep is behind the problem, the big question is why the Black community is hit so hard compared to whites.

In the Express Yourself study, she used imaging data to explore whether racial discrimination was related to sleep quality, and if accelerated aging based on genetic expression is related to sleep quality and cognitive impairment.

“There are a lot of questions we can answer with these two studies that we haven’t been able to answer before. As a social scientist, I’m concerned about why we’re sleeping too much, or not enough. Beyond health behaviors, what is happening in our social environment?” she said.

In the study, she focused on specific genes that turned on when a person experiences danger and the everyday stress of racism, which also weakens the immune response. Those with the most experiences of flight or fight had their genes always turned on, which increases inflammation and reduces the ability of the immune system to fight off flu, COVID, or HIV.

“It increases our risk for cancer, heart attacks, and Alzheimer’s, but we found something to disrupt that relationship. It’s one thing to say that Black people experience racial discrimination and have accelerated aging, but I wanted to test, is there something that we can do?” she said.

Her next study will explore social factors that impact sleep quality and mental health in Black Americans, but also look to methods to improve brain clearance systems while awake through meditation and breathing, despite the circumstances.

“Especially for many of us with sleep apnea and other sleep disorders and just can’t get enough sleep, how are we able to improve this brain clearance without sleep?” she said.

Sleep is best, and while other methods may not be as efficient in clearing brain toxins, it can help.

“Ultimately I’m interested in improving our sleep quality and reducing our risk for Alzheimer’s disease. If we can do one thing to aid both those things, it’s a win for me,” she said.

Last month, she held a data walk, sharing her findings of both studies with study participants. She also invited their partners at Second Baptist Church, Health Equity for African Americans League (HEAAL).

But before any data was released, she said they first shared the information with their study participants. She emphasizes the need for the Black community to understand their rights and know what to watch out for to avoid exploitation of any scientific or clinical studies.

As director of the Center for Environmental Health Disparities Research, which is part of the Black Thriving Initiative, she is excited to be growing and molding the new center to serve the community.

“We are making a mark in the center I’m directing,” she said. “We are committed to making sure that it is a Black center. We want to focus on issues relevant to our communities and connect to people who are interested in the topics of concern for us.”

For the Center for Environmental Health Disparities Research, see https://sites.uci.edu/cehdr/