FRIDAY, March 4, 2022 (American Heart Association News) — Nearly half of all dementia cases in the U.S. may be linked to a dozen modifiable risk factors – most notably high blood pressure, obesity and physical inactivity, according to new research. The findings suggest a large portion of dementia cases could be prevented, especially among Black and Hispanic adults, who had the highest percentage of combined risk factors.
“There are things people can do that can raise or lower their individual risk” for dementia, said Mark Lee, a PhD candidate at the University of Minnesota in Minneapolis. He led the study presented Friday at the American Heart Association’s Epidemiology and Prevention, Lifestyle and Cardiometabolic Health conference.
As the population ages, the number of dementia cases in the U.S. has been climbing. Currently about 5.8 million U.S. adults live with Alzheimer’s disease and related dementias, according to the Centers for Disease Control and Prevention. That number is expected to hit 14 million by 2060, with Black and Hispanic adults seeing the largest increases. Among Hispanic adults, cases are expected to rise sevenfold, while cases among aging Black adults are expected to quadruple.
Those higher rates among Black and Hispanic people may be due to higher rates of heart disease and diabetes, which are linked to dementia risk. Social determinants of health – such as lower levels of education, higher rates of poverty and greater exposure to discrimination – also play a role.
Previous research identified 12 modifiable risk factors believed to be responsible for roughly 40% of dementia cases worldwide. A 2020 report by the Lancet Commission listed these as lower education level, hearing loss, traumatic brain injury, high blood pressure, excessive alcohol consumption, obesity, smoking, depression, social isolation, not getting the recommended amount of physical activity, diabetes and air pollution.
In the new study, researchers wanted to know if some risk factors had a greater influence than others on dementia rates – and how that differed among Black, Hispanic, Asian and white adults. They compiled data from the CDC’s National Health and Nutrition Examination Survey and five other datasets.
Overall, 42.4% of dementia cases in the U.S. were attributable to the 12 factors, with three heart-related factors driving the bulk of that risk across races. High blood pressure, also known as hypertension, contributed to 6.7% of those cases; obesity to 7%; and physical inactivity to 6.7%.
The percentage of dementia cases attributable to those three risk factors was highest among Black adults. But the percentage of all 12 risk factors combined was highest among Hispanic people. Asian people had the lowest percentage of combined risk factors.
The results are considered preliminary until a full paper is published in a peer-reviewed journal.
The findings, Lee said, point to the need for better strategies to reduce heart-related risk factors, which would in turn reduce dementia risk population-wide.
This can, in part, be done through lifestyle changes, combined with medication as needed, said Priya Palta, an assistant professor of medical sciences and epidemiology at Columbia University Irving Medical Center in New York City.
“Maintaining a cognitively and physically active lifestyle and controlling risk factor levels pharmacologically, when necessary, throughout one’s life course is critical for later-life brain health and is likely to impact many of the risk factors examined in this study,” said Palta, who was not involved in the research.
Lee said the next step is to determine which interventions are most effective for reducing each of the 12 modifiable dementia risk factors. He also said a deeper investigation is needed into the social determinants of health underlying racial disparities, such as the disproportionately high rate of hypertension among Black adults.
“That’s a really important direction we need to move to if we are serious about achieving equity in health interventions.”
American Heart Association News covers heart and brain health. Not all views expressed in this story reflect the official position of the American Heart Association. Copyright is owned or held by the American Heart Association, Inc., and all rights are reserved. If you have questions or comments about this story, please email editor@heart.org.
By Laura Williamson
FRIDAY, March 4, 2022 (American Heart Association News) — Eating a predominantly plant-based diet may substantially slow the rate of cognitive decline in older Black adults in the U.S., according to preliminary research.
However, this dietary pattern had less effect on cognitive decline in older white adults, according to the findings presented Friday at the American Heart Association’s Epidemiology and Prevention, Lifestyle and Cardiometabolic Health conference in Chicago.
“It’s not that the diet doesn’t work on white people,” said lead researcher Xiaoran Liu, an assistant professor at Rush University Medical Center’s Institute for Healthy Aging in Chicago. “It just had a greater impact on African Americans.”
Previous studies have found healthy dietary changes can slow cognitive decline, but little research looked at the impact on Black adults, who face roughly twice the risk for dementia as white adults. Other studies have linked a predominantly plant-based diet to a lower risk for stroke, heart disease and Type 2 diabetes.
“Science is really coming out to support the importance of a healthy plant-based diet,” said Maya Vadiveloo, an assistant professor of nutrition and food sciences at the University of Rhode Island. “It doesn’t mean we can’t have any animal-sourced foods or low-fat dairy, but people should focus on eating more legumes and whole grains. These plant-based foods are really important for our overall health.”
In the new study, researchers analyzed diet and cognitive performance over a decade for 4,753 Black and white adults who were 74 years old on average at the start of the study. Based on their scores from self-reported dietary patterns, participants were divided into three groups: those with healthy plant-based diets high in fruits, vegetables, nuts, whole grains, legumes, vegetable oils, tea and coffee; those who ate a less-healthy plant-based diet that included fruit juices, refined grains, potatoes, sugar-sweetened beverages and sweets; and those who ate a diet with animal fats, dairy, eggs, meats, fish or seafood. Overall, Black adults in the study ate more eggs, fish or seafood, sugary drinks and whole grains than their white peers.
Researchers then used tests to measure overall cognition, perceptual speed and episodic memory – the ability to recall personal experiences associated with a particular time and place. The findings showed the healthiest plant-based diet slowed the decline more in all three areas for Black adults than it did for white adults.
Overall cognitive decline slowed by 28.4% among Black adults in the highest bracket of the healthiest eating group compared to their Black peers whose plant-based diet wasn’t as healthy. Black and white adults in the other two dietary categories showed no slowing of overall cognitive decline.
The impact of diet on perceptual speed and episodic memory was even more dramatic for Black adults. Those who ate the healthiest plant-based diet experienced a 49.3% slower decline in perceptual speed and a 44.2% slower decline in episodic memory than their peers who ate a diet with more animal foods. The findings are considered preliminary until a full study is published in a peer-reviewed journal.
There could be many explanations for the disparity between white and Black adults, Liu said. One reason may be Black adults are at higher risk for cardiovascular problems, which affect cognitive health, so reducing that risk by eating a heart-healthy, plant-based diet may have a more pronounced impact on their brain health than on people whose risk is lower to begin with.
Black people in the United States face those higher cardiovascular risks for a number of reasons, including systemic and societal issues that historically have limited access to care, medication, nutritious foods and other resources that can lower risks.
Liu said the disparity in cognitive decline in the study also could be caused by eating patterns. For example, Black adults ate a lot more whole grains than white adults. She is currently analyzing the impact of specific food groups on participants’ cognitive decline.
Vadiveloo, who was not involved in the new research, said she hoped findings like this would motivate people to eat a healthier diet. “Sometimes people are motivated by different health conditions differently. Dementia is pretty motivating for adults, maybe even more so than heart disease.”
Vadiveloo co-authored an AHA scientific statement last November offering dietary guidance to improve heart health. The statement emphasizes the importance of eating a wide range of fruits and vegetables along with whole grains, fish and seafood.
American Heart Association News covers heart and brain health. Not all views expressed in this story reflect the official position of the American Heart Association. Copyright is owned or held by the American Heart Association, Inc., and all rights are reserved. If you have questions or comments about this story, please email editor@heart.org.
By Laura Williamson

source