Effects of Hydroxyhydroquinone-reduced Coffee in Patients with Essential Hypertension

Abstract

Recent animal and human studies suggest that chlorogenic acids, which are the main component of the class of polyphenols in coffee, reduce blood pressure, and that hydroxyhydroquinone (HHQ), produced by roasting green coffee beans, inhibits the antihypertensive effect of chlorogenic acids in brewed coffee. To examine the effects of 4 weeks of daily ingestion of HHQ-reduced coffee in patients with essential hypertension undergoing treatment with antihypertensive drugs. Patients being treated for essential hypertension with antihypertensive drugs participated in a randomized, double-blind, crossover controlled trial. After a 2-week run-in phase, participants consumed two cans of either HHQ-reduced coffee or Control coffee daily for 4 weeks. After a 2-week washout period, subjects were crossed over to the other treatment. Blood pressure and pulse rate were measured once a week. Blood biochemistry and hematology analysis was performed before and after the test beverage ingestion periods. A 4-week ingestion period of HHQ-reduced coffee did not significantly change systolic blood pressure (SBP) or diastolic blood pressure (DBP) compared to the Control coffee. There were no significant changes in pulse rate and body weight during the test beverage ingestion periods in either group, and no clinically relevant problems were reported. These findings suggest that 4 weeks of daily ingestion of HHQ-reduced coffee does not reduce or enhance the efficacy of antihypertensive drugs in treated essential hypertensive patients.

The effects of green coffee bean extract supplementation on lipid profile in humans: A systematic review and meta-analysis of randomized controlled trials

“…Conversely, there are some concerns about potential hepatotoxic effects of green coffee extracts. In an earlier investigation, 2 g of chlorogenic acid/day increased homocysteine concentrations (risk factor for cardiovascular disease) in coffee drinkers [34]. In that study, adverse events appeared, when concentrated green coffee was consumed over a week.…”

“…The characteristics of the included studies are detailed in Table 1. These studies were published between 2005 and 2019 (February) and were conducted in Iran [17,20,29,19], South Korea [32,33], Spain [28], Colombia [31], and Japan [27,30,34,35,36]. The follow-up period ranged from 2 to 12 weeks.…”

High consumption increases sensitivity to after-flavor of canned coffee beverages

“…After percolation, the extract is transferred to a can or other container, and sterilization is performed by exposing the container to high pressure and temperature. Some studies reports that the olfactory (Grosch, 1998;Mayer, Czerny, & Grosch, 2000;Semmelroch & Grosch, 1995) or gustatory (Blumberg, Frank, & Hofmann, 2010;Frank, Blumberg, Krümpel, & Hofmann, 2008;Frank, Blumberg, Kunert, Zehentbauer, & Hofmann, 2007;Frank, Zehentbauer, & Hofmann, 2006) substances that contribute coffee flavor are selectively reduced through the percolation process (Ochiai et al, 2008). In this experiment, we used two types of non-released products (Kao Corporation, Tokyo), samples B and C, among the three samples.…”

The effect of coffee consumption on blood pressure and the development of hypertension

“…Recent research has identified chlorogenic acids (CGAs) that are present in coffee may have an antihypertensive effect and that this may be inhibited by hydroxyhydroquinone (HHQ), which is produced during the roasting of green coffee beans [32,33]. HHQ-reduced coffee has shown some promising results in lowering BP in those with prehypertenison or mild hypertension [34][35][36]; however, one study of patients being treated for essential hypertension revealed no effect on either raising or lowering BP [37]. This interaction of CGA and HHQ may help explain the differential effects of coffee vs. other caffeinated beverages on BP.…”