Acute black tea consumption improves cutaneous vascular function in healthy middle-aged humans

Area of Science:

• Cardiovascular Physiology
• Vascular Biology
• Nutritional Science

Background:

• Dietary flavonoids in black tea may reduce cardiovascular disease (CVD) risk.
• Improved nitric oxide (NO)-mediated vascular function is a potential mechanism.
• The study investigated black tea's acute effects on cutaneous microvascular function.

Purpose of the Study:

• To examine the impact of acute black tea ingestion on skin blood flow.
• To assess changes in cutaneous vascular conductance (CVC) and perfusion.
• To differentiate between axon- and endothelium-dependent vasodilation.

Main Methods:

• Randomized, controlled, double-blind, cross-over study with 20 healthy participants.
• Participants consumed 200 ml black tea or placebo.
• Forearm cutaneous perfusion assessed using laser-Doppler flowmetry (LDF) and full-field laser perfusion imaging (FLPI) under different heating protocols.

Main Results:

• Black tea significantly increased absolute CVC and flux during gradual local heating to 42°C (P < 0.001).
• No significant effects were observed with rapid heating protocols (39°C or 42°C).
• Maximal CVC (%CVCmax) was not affected by tea ingestion.

Conclusions:

• Acute black tea intake enhances cutaneous vascular responses to gradual heating in healthy, middle-aged individuals.
• This effect may involve the activation of endothelium-derived mediators, such as NO.
• These findings support the potential cardiovascular health benefits of regular tea consumption.