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Published on: May 17, 2024
Hydroxyhydroquinone-free coffee: a double-blind, randomized controlled dose-response study of blood pressure
Tohru Yamaguchi1, Akiro Chikama, Kenta Mori
1Health Care Food Research Laboratories, Kao Corporation, 2-1-3 Bunka, Sumida, Tokyo 131-8501, Japan. yamaguchi.tohru@kao.co.jp
Background And Aim:
Coffee is rich in chlorogenic acids (CGA), whose metabolites may have beneficial effects such as anti-hypertensive effects. However, trial results concerning the effects of coffee on blood pressure (BP) are not consistent. A recent study suggested that hydroxyhydroquinone (HHQ), produced by the roasting of green coffee beans, inhibits the effect of CGA. In the present study, the dose-response for CGA in HHQ-free coffee on BP were investigated in mildly hypertensive men and women.
Methods And Results:
The trial design was a double-blind, randomized controlled trial, with five study groups including, control, zero-dose, low-dose, middle-dose and high-dose. The control beverage was identical to ordinary coffee. The others contained reduced HHQ levels, compared to ordinary coffee, and the CGA were adjusted in target concentration. A total of 203 subjects were randomly allocated. Each subject drank one cup of coffee per day. The study involved a screening and a baseline observation period of 6 weeks and an intervention period of 4 weeks. BP response showed CGA has an anti-hypertensive effect in a dose-dependent manner in HHQ-free coffee, and ordinary coffee showed almost no effect. As a result, a significant correlation between BP change and the three dose-response patterns was observed (p<0.001).
Conclusions:
This study demonstrates a dose-dependent decrease in BP for CGA in HHQ-free coffee.
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