Effects of hot tea, coffee and water ingestion on physiological responses and mood: the role of caffeine, water and beverage type

Abstract

Psychopharmacological studies using caffeinated beverages or caffeine have rarely considered temporal effects on psychological and physiological function or the specific contribution of caffeine, hot water, or beverage type to the observed effects. The effect of 400 ml hot tea, coffee, and water consumption on systolic and diastolic blood pressure (SBP and DBP), heart rate, skin conductance (a measure of sympathetic nervous system activation), skin temperature, salivary cortisol, and mood were monitored in 16 healthy caffeine-withdrawn (14 h) subjects in a complete crossover design. Beverages were ingested with/without 100 mg caffeine and milk (tea/coffee only). Hot beverage ingestion rapidly increased skin conductance and temperature (+1.7 degrees C) with peak effects observed only 10-30 min post-consumption. Caffeine in the beverage rapidly augmented skin conductance responses but, in contrast to the effect of hot water, reduced the skin temperature response and increased SBP (+2.8 mmHg) and DBP (+2.1 mmHg) 30-60 min post-consumption. Both caffeine and milk addition to beverages independently improved mood and reduced anxiety 30 and 60 min post-consumption. Milk addition had no other effects apart from attenuating the transient increase in physiological responses associated with the drinking phase. There were no effects of beverage consumption on salivary cortisol or of beverage vehicle on salivary caffeine levels, the latter indicating that caffeine pharmacokinetics was similar in both tea and coffee, and not different from caffeinated water. In keeping with this, the responses to tea and coffee ingestion were similar and largely accounted for by the effects of hot water and caffeine. However, tea potentiated the increase in skin temperature compared to coffee and water indicative of a greater vasodilatory response plausibly related to the presence of flavonoids in tea. We conclude that ingestion of hot caffeinated beverages stimulates physiological processes faster than hitherto described, primarily via the effects of hot water and caffeine, but with beverage type and milk playing important modulatory roles.

Expectation of having consumed caffeine can improve performance and mood

“…Peeling & Dawson, 2007). Placebo-controlled trials using objective measures can corroborate these reports; consumption of caffeine can produce significant improvements in: reaction time, short-term memory, vigilance, reasoning, response accuracy, attention, and general alertness (see Glade, 2010) Paralleling its effects on cognition, caffeine consumption is also accompanied by improved mood including increased 'happiness' (Amendola, Gabrieli & Lieberman, 1998), a reduction in depressive symptoms (Childs & de Wit, 2008), and decreased anxiety (Quinlan, Lane & Aspinall, 1997), although there are conflicting results with respect to anxiety (Broderick & Benjamin, 2004).…”

Caffeine Use in Sports: Considerations for the Athlete

“…Taken orally, caffeine reaches a peak plasma level between 30 and 75 minutes after ingestion (53). The half-life of caffeine has been reported to be 4 to 5 hours with a modest intake of coffee, but longer when the dose exceeds 300 mg; this value may vary between acute and chronic users (41,42,61).…”

“…Caffeine may result in dizziness, headache, jitteriness, nervousness, insomnia, and gastrointestinal distress, generally at doses greater than 9 and 13 mgÁkg 21 of caffeine for nonusers and users, respectively (12,19,41,53). These signs and symptoms at high doses may be linked to decreased performance in some athletes (24,28,54).…”

Good Mood Foods

“…Some people, for instance, find that taking a pain medicine or using a cold or hot pack works faster and better when they relax at the same time. Quinian et al [21] based on psychopharmacological studies concluded that ingestion of hot caffeinated beverages stimulates physiological processes faster than hitherto described, primarily via the effects of hot water and caffeine, but with beverage type and milk playing important modulatory roles.…”

“…The improvement of mood is among the effects attributed to caffeine in coffee drinkers [21]. Over consumption of coffee increase caffeine content of body which suppresses the serotonin, it leads to depression.…”