Coffee drinking induces incorporation of phenolic acids into LDL and increases the resistance of LDL to ex vivo oxidation in humans.
ABSTRACT Epidemiologic and intervention studies indicate that both diet as a whole and single dietary components are involved in the risk of atherosclerosis. The resistance of LDL to oxidative modification is an ex vivo indicator of risk, which is modulated by dietary components. Coffee contains phenolic compounds with antioxidant activity. These molecules are found in plasma after the consumption of coffee, and it has been shown that, in vitro, they are able to decrease the susceptibility of LDL to oxidation.
The aim of this study was to evaluate the effect of coffee consumption on the redox status of LDL as modulated by the possible incorporation of phenolic acids into LDL.
Ten healthy volunteers, after an overnight fast, drank 200 mL filtered coffee. Blood was drawn before and 30 and 60 min after drinking. Changes in LDL redox status were evaluated by the measure of LDL resistance to oxidative modification and the concentration of LDL(-), a mildly modified, electronegative LDL subfraction. Chlorogenic and phenolic acids concentration in LDL were measured by electrochemical HPLC.
The resistance of LDL to oxidative modification increased significantly after coffee drinking, but the LDL(-) concentration did not increase. The concentration into LDL of conjugated forms of caffeic, p-coumaric, and ferulic acids increased significantly after coffee drinking.
Drinking 200 mL (1 cup) coffee induces an increase in the resistance of LDL to oxidative modification, probably as a result of the incorporation of coffee's phenolic acids into LDL.
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ABSTRACT: Objective: We aimed to use the meta-analysis method to assess the relationship between coffee drinking and all-cause mortality. Design: Categorical and dose–response meta-analyses were conducted using random-effects models. Setting: We systematically searched and identified eligible literature in the PubMed and Scopus databases. Subjects: Seventeen studies including 1 054 571 participants and 131 212 death events from all causes were included in the present study. Results: Seventeen studies were included and evaluated in the meta-analysis. A U-shaped dose–response relationship was found between coffee consumption and all-cause mortality (P for non-linearity < 0·001). Compared with non/occasional coffee drinkers, the relative risks for all-cause mortality were 0·89 (95 % CI 0·85, 0·93) for 1– < 3 cups/d, 0·87 (95 % CI 0·83, 0·91) for 3– < 5 cups/d and 0·90 (95 % CI 0·87, 0·94) for ≥5 cups/d, and the relationship was more marked in females than in males. Conclusions: The present meta-analysis of prospective cohort studies indicated that light to moderate coffee intake is associated with a reduced risk of death from all causes, particularly in women. Coffee is one of the most popular beverages in the world and the health-related effects of coffee have been fre-quently studied. Habitual coffee drinking was reported to be inversely related to the risks of type 2 diabetes (1) and chronic liver disease (2) . As a major dietary source of anti-oxidants, coffee may also help to improve the resistance of LDL to oxidation and reduce oxidative DNA damage (3) . Results from prospective cohort studies regarding the association of habitual coffee drinking with all-cause mortality were inconclusive (4–6) . O'Keefe et al. (7) recom-mended that moderate intake of coffee, tending towards two or three to as many as four cups daily, would be a better choice for keeping healthy rather than excessive coffee consumption. Besides, the association of coffee intake with all-cause mortality may differ between men and women. Lopez-Garcia et al. (8) observed that the sig-nificant inverse association of coffee drinking with total mortality was attenuated in men when compared with that in women. Similar results were also found in another large cohort study (9) . A recent meta-analysis of prospective cohort studies suggested that moderate coffee intake was associated with a lower risk of CHD in female drinkers but not in menPublic Health Nutrition 05/2015; DOI:10.1017/S1368980014001438 · 2.48 Impact Factor