- Adopting a predominantly plant-based diet significantly reduces the rate of cognitive decline in older Black adults in the United States, according to new research.
- White adults also experienced cognitive benefits from a plant-based diet, but these effects were less pronounced than in Black adults.
- In the study, participants were grouped based on their diet: healthy plant-based, less healthy plant-based, or diets rich in animal fats and proteins.
- Black adults who consumed healthier plant-based options showed 49.3% slower decline in perceptual speed and 44.2% slower decline in episodic memory compared to those who ate more animal-sourced foods.
- Multiple factors may explain the significant variation in cognitive benefits derived from plant-based diets between Black and white adults, including variation in dietary habits or a higher risk of cardiovascular complications amongst Black adults.
Consuming a mainly plant-based diet could significantly decelerate cognitive decline in older Black adults within the United States, reveals novel preliminary research.
However, the influence of this dietary pattern on cognitive decline appears less significant in older white adults, as indicated by the research findings.
The Effect of Plant-Based Diets on Different Races
The researcher, Xiaoran Liu from the Institute for Healthy Aging at Rush University Medical Center, clarified on the results. “It’s not that the diet doesn’t have any effect on white people. It just has a greater significance on African Americans,” she stated.
Prior research suggested that healthier dietary modification can hinder cognitive decline, but there’s limited research focusing on its effects on Black adults, who have about twice the susceptibility to dementia compared to their white counterparts. Furthermore, several studies associate a predominantly plant-based diet with reduced risk for stroke, heart disease, and Type 2 diabetes.
“We’ve seen strong scientific evidence supporting the significance of a healthy plant-based diet,” notes Maya Vadiveloo, a Nutrition and Food Sciences professor from the University of Rhode Island. “Though this doesn’t necessarily mean giving up animal-sourced foods, it should inspire people to incorporate more legumes and whole grains into their diets. Plant-based foods contribute significantly to our overall health,” she adds.
Unveiling the Study
In this study, researchers investigated the diet and cognitive performance over a decade of 4,753 Black and white adults with an average age of 74 years at the beginning of the study. Participants were assessed based on their diet patterns and were categorized into three groups:
- Those who adhered to healthy plant-based diets consisting of fruits, vegetables, nuts, whole grains, legumes, vegetable oils, tea, and coffee
- Those who consumed a less-healthy plant-based diet with fruit juices, refined grains, potatoes, sugar-sweetened beverages, and sweets
- Those whose diets were rich in animal fats, dairy, eggs, meats, fish, or seafood.
The study found that Black adults tended to consume more eggs, fish or seafood, sugary drinks, and whole grains than their white counterparts.
Interpreting the Findings
Researchers used tests to assess cognition, perceptual speed, and episodic memory – or the ability to remember personal experiences associated with specific times and places. The evidence demonstrated that a healthy plant-based diet slowed decline in all three categories to a greater extent for Black adults than for white adults.
The most dramatic impact was seen in perceptual speed and episodic memory, where Black adults who consumed the healthiest plant-based options experienced 49.3% slower decline in perceptual speed and 44.2% slower decline in episodic memory compared to those who ate more animal-sourced foods.
These fascinating findings are preliminary until a comprehensive study is published in a peer-reviewed journal.
Various explanations could account for the marked disparity between white and Black adults. One possibility is the higher risk of cardiovascular complications among the Black population, which impacts cognitive health. Thus, adopting a heart-healthy, plant-based diet might have a noticeably larger effect on the brain health of individuals at higher risk.
The study’s author also speculates that this discrepancy could be due to dietary habits, as Black adults consumed significantly more whole grains than white adults. Further analysis is being conducted to determine the impact of specific food groups on participants’ cognitive decline.
Vadiveloo voices hope that studies like this one will inspire people to adopt healthier eating habits. “People are often motivated differently by various health conditions. The fear of dementia can act as a strong catalyst for adults, possibly more so than heart disease,” she said.
By Laura Williamson