If you believe you’re impervious to the negative effects of an evening soda or other caffeinated beverage, you might want to listen up. Recent research finds that caffeine can affect sleep in ways beyond cutting your bedtime hours short. Scientists in Poland reviewed dozens of studies looking at how caffeine might influence the brain’s electrical activity during sleep. They found evidence that caffeine can subtly reduce the time people spend in deep sleep, even if they subjectively report feeling plenty restful in the morning. The findings support the medical advice that we should be mindful about our caffeine intake, especially later on in the day. “Caffeine reliably alters the neurophysiological architecture of human sleep in a direction consistent with reduced sleep depth and weakened homeostatic recovery,” the researchers wrote in their paper, published in the journal Nutrients.…