Coffee perks up brain function in AF patients

Daily coffee drinking may provide atrial fibrillation (AF) patients with cognitive benefits, as suggested in a study.

In a cohort of 2,413 participants (mean age 73 years, 72.6 percent male, 49.6 percent had average level of education) from the Swiss‐AF cohort, those who drank more coffee performed better on the cognitive construct (CoCo) and Montreal Cognitive Assessment (MoCA) compared with those who drank less than 1 cup per day. [J Am Heart Assoc 2024;doi:10.1161/JAHA.124.0343]

For both CoCo and MoCA, the highest estimated score was observed among participants who drank more than 5 cups of coffee per day. The associations between coffee consumption and CoCo and MoCA scores were robust, dose‐dependent, and detectable starting at 1 cup of coffee. Linear trend estimates showed that each higher consumption quantity category was associated with a 0.11-additional point (95 percent confidence interval [CI], 0.03–0.20) in CoCo score (p=0.01) and a 0.43-additional point (95 percent CI, –0.17 to 1.05) in MoCA score (p=0.16). The consumption quantity categories were as follows: <1, 1, 2-3, 4-5, and >5 cups per day.

These findings have important implications, with a 1‐point difference in the MoCA score having been shown to be equivalent to an average 10‐year age difference or the presence of diabetes or arterial hypertension, according to the investigators. “Accordingly, the effect size of more than 5 cups per day is comparable with a calculated age difference of 6.7 years.” [J Am Coll Cardiol 2019;73:989-999]

Reduced inflammation

In the cohort, most participants (48.3 percent) were consuming 2-3 cups of coffee per day. The mean BMI of participants across all consumption quantity categories was >25 kg/m². Notably, the highest consumption quantity category (>5 cups per day) had the highest prevalence of diabetes (21.4 percent) but the lowest prevalence of arterial hypertension (61.9 percent). Participants who drank more than 5 cups of coffee per day were also more likely than those in other consumption quantity categories to be an active smoker (23.8 percent).

“Our findings showed that the highest coffee consumers reached the highest estimated MoCA score (25.25) despite exhibiting the highest risk profile (highest BMI, active smokers), incidence of diabetes, lower educational level, and physical activity,” the investigators noted. “Accordingly, this group showed [the] second highest prevalence for stroke.”

Another interesting finding was the dose-dependent reductions in hs‐CRP and IL‐6 concentrations across the coffee consumption quantity categories, they added. Participants who drank more than 5 cups per day saw a 27-percent and a 22-percent decrease in hs‐CRP and IL‐6 levels, respectively.

“The reduction of inflammatory mediators in AF patients triggered by ischaemia, oxidative stress, and impaired integrity of the blood–brain‐barrier may explain our findings and is in line with recent studies. [These data are] of twofold importance because they may point to a mechanistic explanation of the effect that cannot be explained by a simple, caffeine‐induced short‐term increase in alertness in the test setting,” the investigators said.

They pointed out that while acute, high-dose caffeine consumption can provide a temporary boost in alertness, low-dose consumption may offer more sustained cognitive benefit. Given that the half‐life of caffeine is on average 5 hours and may reach up to 10 hours in older adults, it is likely that the mechanisms underlying the observed cognitive benefits may extend beyond acute arousal, they added. [Nutr Rev 2008;66:82-90; Anal Bioanal Chem 2013;405:8487-8503]

“Based on our findings and the current literature, clinicians should not discourage regular coffee consumption in patients with AF,” the investigators said.

The study was limited by its observational nature and the potential for recall bias and individual variability of coffee consumption (cup size, type and strength of coffee, and methods of preparation), among others.