Older adults who consume more caffeine may be less likely to experience cognitive decline, according to a new population-based study using U.S. health survey data. The findings suggest that higher levels of caffeine intake are associated with improved cognitive functioning, particularly in domains related to memory and attention. The study was published in the Journal of Human Nutrition and Dietetics.
As the global population ages, cognitive decline has become a growing public health concern. Conditions such as Alzheimer’s disease and related forms of dementia are rising in prevalence, placing increasing burdens on individuals, caregivers, and healthcare systems. While there are currently no widely available treatments to reverse cognitive impairment, researchers have focused on identifying lifestyle factors that might help delay or prevent its onset.
Diet is one such factor. Among the many components of a typical diet, caffeine has drawn particular interest because of its widespread use and potential impact on brain health. Previous studies have proposed that caffeine may improve alertness, memory, and attention by blocking adenosine receptors and promoting neurotransmitter release.
Some researchers have also pointed to the antioxidant and anti-inflammatory effects of caffeine as possible mechanisms for protecting brain function. However, most of the evidence comes from experimental or small-scale studies. Large population-based investigations examining the association between caffeine intake and cognitive outcomes have been limited.
To help address this gap, researchers from Shanxi Province in China used nationally representative data from older U.S. adults to evaluate whether caffeine intake is linked to cognitive performance. By analyzing a large, diverse sample, the study aimed to clarify whether the relationship between caffeine and cognition holds up across different groups and consumption levels.
The study analyzed data from 2,461 adults aged 60 and older who participated in the National Health and Nutrition Examination Survey (NHANES) during the 2011 to 2014 cycles. NHANES is a well-known survey conducted by the U.S. Centers for Disease Control and Prevention that collects detailed information about health, diet, and behavior from a representative sample of the non-institutionalized population.
Caffeine intake was assessed using a 24-hour dietary recall interview, which asked participants to report all food, drinks, and supplements they consumed the previous day. Trained personnel used a standardized method to ensure the accuracy of reporting. While dietary recall may not reflect long-term habits, it can offer a snapshot of typical consumption patterns, especially when standardized across a large sample.
To measure cognitive function, participants completed three standard assessments: the CERAD Word Learning Test (which evaluates verbal memory), the Animal Fluency Test (which assesses verbal fluency and executive function), and the Digit Symbol Substitution Test (which gauges processing speed and attention). Researchers combined these scores into a composite measure, with lower scores indicating poorer cognitive function.
The team used multivariable logistic regression models to analyze whether caffeine intake was linked to cognitive performance, adjusting for a range of factors that might also influence cognition. These included age, sex, education, marital status, body mass index, smoking and drinking habits, and medical history, including diabetes, hypertension, and stroke.
The results indicated a consistent association between higher caffeine intake and better cognitive function. In the fully adjusted model, each 80 milligram increase in daily caffeine consumption—roughly the amount in a cup of tea or a small cup of coffee—was linked to a 12 percent reduction in the odds of having poor cognitive function. Participants in the highest quartile of caffeine intake had a 42.5 percent lower risk of poor cognitive function compared to those in the lowest quartile.
A dose-response pattern emerged from the data: the more caffeine participants consumed, the less likely they were to exhibit cognitive impairment. This pattern appeared largely linear, based on a statistical method called restricted cubic spline analysis. Even after performing sensitivity tests and subgroup analyses to account for demographic and health differences, the inverse association between caffeine intake and poor cognition remained robust.
When broken down by age and sex, the findings suggested that younger participants (under 75) and men tended to benefit more from caffeine intake than older participants and women, although the differences were not statistically significant in all comparisons. Among men, those in the highest caffeine group had about one-third the odds of cognitive impairment compared to those in the lowest group. For women, the pattern was less consistent.
The relationship between caffeine and cognition also held across groups defined by education level, marital status, smoking, and drinking behaviors. Even among participants without a history of diabetes, hypertension, or stroke, higher caffeine intake was associated with better cognitive performance.
While the findings are suggestive, they come with several caveats. The study was cross-sectional, meaning all data were collected at one point in time. This design makes it impossible to determine cause and effect. It remains unclear whether caffeine protects against cognitive decline, or whether individuals with better cognitive function are more likely to consume caffeine regularly.
The use of a single 24-hour dietary recall may not fully capture long-term caffeine consumption habits. Although the recall method was standardized and professionally administered, there is still a risk of underreporting or overreporting, especially when it comes to items like tea, coffee, energy drinks, or supplements.
Cognitive function was measured using standardized tests rather than clinical diagnoses. While these tools are widely accepted and useful for research, they may not detect subtle impairments or distinguish between different types of cognitive decline.
The researchers also acknowledged the lack of data on other relevant factors such as physical activity, sleep quality, or genetics. For example, individual differences in caffeine metabolism, influenced by genetic variations, could affect how caffeine impacts the brain. Some people process caffeine more slowly, which may lead to longer-lasting effects on alertness or sleep, potentially altering its cognitive impact.
Another complication lies in the distinction between caffeine and coffee. Coffee contains other compounds such as chlorogenic acids and diterpenes, which may have independent or synergistic effects on brain health. By focusing specifically on caffeine from all dietary sources, including tea, soda, and chocolate, the study attempted to isolate caffeine’s role. However, it does not exclude the possibility that these other compounds contribute to the observed associations.
The study, “Caffeine Intake and Cognitive Function Among US Adults Aged 60+: Insights From NHANES 2011−2014,” was authored by Xiaoli Wang, Meng Li, and Minheng Zhang.
