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Black tea increases coronary flow velocity reserve in healthy male subjects

Kumiko Hirata1, Kenei Shimada, Hiroyuki Watanabe

  • 1Department of Medicine, Division of Cardiology, College of Physicians & Surgeons, Columbia University, New York, NY, USA.

The American Journal of Cardiology
|May 29, 2004
PubMed

Insights

Black tea consumption significantly improves coronary flow velocity reserve (CFVR), a measure of coronary circulation function. This study demonstrates acute benefits of black tea on heart blood vessel health.

Area of Science:

  • Cardiology
  • Cardiovascular Physiology
  • Nutritional Science

Background:

  • Epidemiological studies indicate tea consumption is linked to reduced cardiovascular event risk.
  • Clinical evidence on tea's direct impact on coronary circulation is lacking.
  • Coronary flow velocity reserve (CFVR) is a key indicator of coronary circulatory function.

Purpose of the Study:

  • To investigate the acute effects of black tea consumption on coronary flow velocity reserve (CFVR).
  • To compare the impact of black tea versus caffeine on coronary circulation.
  • To utilize transthoracic Doppler echocardiography (TTDE) for CFVR assessment.

Main Methods:

  • A double-blind, crossover study involving 10 healthy male volunteers.
  • Measurement of coronary flow velocity in the left anterior descending coronary artery using TTDE.
  • Assessment of CFVR at baseline and during hyperemia induced by adenosine triphosphate infusion, before and after consuming black tea or caffeine.

Main Results:

  • Two-way ANOVA revealed significant effects of beverage type and consumption timing on CFVR (p = 0.001).
  • Black tea consumption led to a significant increase in CFVR (4.5 ± 0.9 to 5.2 ± 0.9, p < 0.0001).
  • The CFVR ratio was significantly higher after black tea consumption compared to caffeine (1.18 ± 0.07 vs. 1.04 ± 0.08, p = 0.002).

Conclusions:

  • Acute consumption of black tea enhances coronary vessel function.
  • The improvement in coronary circulation is evidenced by a significant increase in CFVR.
  • Black tea demonstrates a more pronounced effect on CFVR compared to caffeine.

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