AI uses simple health data to predict your brain speed

Scientists have developed a machine learning algorithm that predicts how quickly your brain processes information using only some basic health measurements.

The new study shows that age, blood pressure and body mass index are the strongest predictors of cognitive performance, which is stronger than diet or exercise habits. This finding could change how doctors identify people with cognitive decline, which could be years before symptoms appear.

The study, published in the Journal of Nutrition, analyzed data from 374 adults aged 19 to 82 to determine which health factors best predict the performance of cognitive tests. Unlike traditional studies that examine one factor at a time, this approach uses artificial intelligence to evaluate multiple variables simultaneously.

Three key predictors emerge

“This study used machine learning to evaluate many variables at once to help identify those that best align with cognitive performance,” said Naiman Khan, professor of health and kinesiology at Urbana-urbana-Champaign, University of Illinois. “Standard statistical methods cannot accept this complexity at once.”

The algorithm performed a flanking task test on participants, a well-recognized cognitive test where one had to focus on the central arrow while ignoring distraction arrows pointing in different directions. Faster reaction times indicate better brain function.

After analyzing 18 different health and lifestyle factors, machine learning models identify important hierarchies. The importance score of age was 0.208, followed by diastolic blood pressure of 0.169 and BMI of 0.079. Surprisingly, factors such as gender and race had the lowest predictive power, with scores of 0.003 and 0.005, respectively.

Diastolic blood pressure is more important than systolic blood pressure

One particularly interesting finding not highlighted in the initial study abstract involves blood pressure measurements. This study shows that diastolic blood pressure (the base of blood pressure reading) predicts cognitive performance more significantly than systolic blood pressure (the highest number).

This distinction is important because diastolic pressure reflects the constant pressure of the arteries between the heartbeat, which may indicate how blood vessels deliver oxygen to the brain during rest. The findings suggest that sustained vascular health may be more important than peak blood pressure spikes.

Key findings include:

• Age is the most influential predictor with a score of 0.208
• Diestolic blood pressure ranked second in 0.169, with a systolic blood pressure of over 0.069
• The BMI score is 0.079, ranking it among all the factors tested
• Diet quality (Healthy Diet Index) scored 0.048, showing moderate but meaningful effects
• Sports activity appears as a moderate predictor of 0.034

Diet quality is still important

Although physical factors dominate the predictions, diet quality still plays a measurable role. A healthy dietary index is a comprehensive measure of someone following dietary guidelines, with an importance of 0.048, ranking fifth in total.

“Abide by a healthy diet index, a measure of diet quality, is related to the excellent executive function and processing speed of older people,” Khan explained. The study also examined other dietary patterns, including the Mediterranean, dash and mindful diet, although these dietary patterns showed a smaller impact.

Interestingly, interaction analysis of this study showed that good dietary quality could partially offset the negative cognitive effects of higher BMI. This shows that even if you take on extra weight, your diet is important.

Machine Learning Reveals Hidden Patterns

This study is particularly valuable because it uses advanced analysis to discover patterns that humans may miss. Traditional research methods usually examine one or two factors at a time, but cognitive health involves complex interactions between multiple variables.

“Obviously, cognitive health is driven by many factors, but which ones are most important?” said Shreya Verma, first author of the study and a PhD in Kinesiology. student. “We want to evaluate the relative strength of each factor in combination with other factors.”

Random forest algorithms (the best performing model) achieve excellent accuracy. Its prediction is usually within 0.7 milliseconds of the actual reaction time, less than 0.2% of the average response time.

Two-way interaction tells a bigger story

The researchers did not stop identifying individual predictors. They also examined how factors work together through two-way interactive analysis. These suggest that the combination of risk factors may complicate cognitive effects, while protective factors can work together.

For example, higher dash diet adherence is associated with faster response times at all blood pressure levels, but is most noticeable for people with lower blood pressure. This suggests that diet and cardiovascular health work together rather than independent.

Precision medicine for the brain

“This study reveals how machine learning brings precision and nuance to the field of nutritional neuroscience,” Khan noted. “By moving beyond traditional methods, machine learning can help customize strategies for aging population, people with metabolic risks, or people trying to enhance cognitive function through lifestyle changes.”

These implications go beyond personal health. Since dementia cases are expected to triple by 2050, early identification of people at high risk can be more effective in helping target interventions.

But can these findings actually help prevent cognitive decline? Cross-sectional design means that researchers are unable to prove causality yet. However, strong associations suggest that monitoring blood pressure and maintaining a healthy weight may be more important than previously realized.

The research team plans to validate these findings in a larger, more diverse population and explore whether the same pattern holds over time. They also look at whether specific nutrients in a healthy diet can bring cognitive benefits.

At the moment, the information seems clear: Your brain processes more than just getting older. The healthy choices you make – especially those that affect your cardiovascular system – may play a bigger role in maintaining a sharp mind.

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