Scientists have developed a machine learning algorithm that can predict how quickly your brain processes information using just a few basic health measurements.
The new study reveals that age, blood pressure, and body mass index are the strongest predictors of cognitive performance—more powerful than diet or exercise habits. This discovery could transform how doctors identify people at risk for cognitive decline, potentially years before symptoms appear.
The research, published in The Journal of Nutrition, analyzed data from 374 adults aged 19 to 82 years to determine which health factors best predicted performance on cognitive tests. Unlike traditional studies that examine one factor at a time, this approach used artificial intelligence to evaluate multiple variables simultaneously.
Three Key Predictors Emerge
“This study used machine learning to evaluate a host of variables at once to help identify those that align most closely with cognitive performance,” said Naiman Khan, a professor of health and kinesiology at the University of Illinois Urbana-Champaign who led the research. “Standard statistical approaches cannot embrace this level of complexity all at once.”
The algorithm tested participants on a flanker task—a well-established cognitive test where people must focus on a central arrow while ignoring distracting arrows pointing in different directions. Faster reaction times indicate better brain function.
After analyzing 18 different health and lifestyle factors, the machine learning model identified a clear hierarchy of importance. Age topped the list with an importance score of 0.208, followed by diastolic blood pressure at 0.169 and BMI at 0.079. Surprisingly, factors like sex and ethnicity had minimal predictive power, scoring just 0.003 and 0.005 respectively.
Diastolic Pressure Matters More Than Systolic
One particularly intriguing finding that wasn’t highlighted in the initial research summary involves blood pressure measurements. The study revealed that diastolic blood pressure—the bottom number in a blood pressure reading—was significantly more predictive of cognitive performance than systolic pressure (the top number).
This distinction matters because diastolic pressure reflects the constant pressure in arteries between heartbeats, potentially indicating how well blood vessels deliver oxygen to the brain during rest periods. The finding suggests that sustained vascular health may be more critical for brain function than peak blood pressure spikes.
Key Findings Include:
- Age was the most influential predictor with a score of 0.208
- Diastolic blood pressure ranked second at 0.169, outweighing systolic pressure at 0.069
- BMI scored 0.079, placing it third among all factors tested
- Diet quality (Healthy Eating Index) scored 0.048, showing modest but meaningful impact
- Physical activity emerged as a moderate predictor at 0.034
Diet Quality Still Matters
While physical factors dominated the predictions, diet quality still played a measurable role. The Healthy Eating Index—a comprehensive measure of how well someone follows dietary guidelines—scored 0.048 in importance, ranking fifth overall.
“Adherence to the healthy eating index, a measure of diet quality, has been linked to superior executive function and processing speed in older adults,” Khan explained. The research also examined other dietary patterns including Mediterranean, DASH, and MIND diets, though these showed smaller effects.
Interestingly, the study’s interaction analyses revealed that good diet quality could partially offset negative cognitive effects from higher BMI. This suggests that what you eat matters even if you’re carrying extra weight.
Machine Learning Reveals Hidden Patterns
What makes this research particularly valuable is its use of advanced analytics to uncover patterns humans might miss. Traditional research methods typically examine one or two factors at a time, but cognitive health involves complex interactions between multiple variables.
“Clearly, cognitive health is driven by a host of factors, but which ones are most important?” said Shreya Verma, the study’s first author and a kinesiology Ph.D. student. “We wanted to evaluate the relative strength of each of these factors in combination with all the others.”
The random forest algorithm—the best performing model—achieved remarkable accuracy. Its predictions were typically within 0.7 milliseconds of actual reaction times, representing less than 0.2% of the average response time.
Two-Way Interactions Tell a Bigger Story
The researchers didn’t stop at identifying individual predictors. They also examined how factors work together through two-way interaction analyses. These revealed that combinations of risk factors could compound cognitive effects, while protective factors could work synergistically.
For example, higher DASH diet adherence was associated with faster reaction times across all blood pressure levels, but the benefits were most pronounced in people with lower blood pressure. This suggests that diet and cardiovascular health work together rather than independently.
Precision Medicine for the Brain
“This study reveals how machine learning can bring precision and nuance to the field of nutritional neuroscience,” Khan noted. “By moving beyond traditional approaches, machine learning could help tailor strategies for aging populations, individuals with metabolic risks or those seeking to enhance cognitive function through lifestyle changes.”
The implications extend beyond individual health. With dementia cases expected to triple by 2050, identifying at-risk individuals early could help target interventions more effectively.
But can these findings actually help prevent cognitive decline? The cross-sectional design means researchers can’t prove causation yet. However, the strong associations suggest that monitoring blood pressure and maintaining healthy weight could be more important for brain health than previously realized.
The research team plans to validate these findings in larger, more diverse populations and explore whether the same patterns hold over time. They’re also investigating whether specific nutrients within healthy diets drive the cognitive benefits.
For now, the message seems clear: your brain’s processing speed isn’t just about getting older. The health choices you make—particularly those affecting your cardiovascular system—may play a bigger role in maintaining sharp thinking than anyone realized.